FCTM All Weather Operations

Dear Readers, Important notice This guide is intended to provide general information regarding All Weather Operations. In no case it is intended to replace the operational and flight manuals for ATR aircraft. In all events, the information contained in the Aircraft Flight Manual shall prevail over the content of this guide.

Every effort has been made to ensure document quality. However please do not hesitate to share your comments and information with us by using the following address: [email protected] We would also like to thank ENAC (Ecole Nationale de l’Aviation Civile) for its involvement in the development of this guide. Yours faithfully,

Printed on 100% recycled paper using vegetable inks

Your ATR Training and Flight Operations support team.

© ATC June 2010 All reasonable care has been taken by ATC to ensure the accuracy of the present document. However this document does not constitute any contractual commitment from the part of ATC which will offer, on request, any further information on the content of this brochure. Information in this brochure is the property of ATC and will be treated as confidential. No use or reproduction or release to a third part may be made there of other than as expressely authorised by ATC.

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Dear Readers, The ATR operational documentation chapters related to CAT II precision approaches are being revised (AFM 7-01-03 CATII Operation and FCOM 2-02-04 AFCS). The revision has been recently implemented for 42300/42-320 series and will be extended to the other aircraft types at their next documentation normal revision during the year 2010. The major evolution to notice is a change of the tasks management in the operational procedure, as described in Chapter E. Flight Crew Operating Procedures of this manual. Until the effective revision of the ATR operational documentation, the information contained in the Airplane Flight Manual shall prevail over the content of this manual. Your ATR Training and Flight Operations support team.

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Introduction The purpose of this guide is to provide ATR aircraft pilots and operators with information and regulatory material relating to All Weather Operations. Training pilots for All Weather Operations is the operator’s responsibility. This guide aims to give pilots a good overview on low visibility operations and to help operators develop their own documentation and their flight crew training programmes in order to obtain the Low Visibility Operations approval from their national authority. Most stated recommendations are issued from ICAO annexes and from FAA and EASA regulations. Nevertheless, some national authorities may have additional requirements. The content of this guide is intentionally limited to operations for which ATR aircraft have a technical capability, that is to say: low visibility take-off, lower than standard Category I, Category II, other than standard Category II and Category IIIA approaches. The overall safety level of low visibility operations is achieved through the implementation of specific rules and requirements equally concerning: – the aircraft – the airfield – the flight crew – the operator All 4 fields are addressed in this guide but with an emphasis on the last two items being more widely developed. This guide incorporates features of the ATR -600 aircraft type due for entry into service by 2011. For the time being, low visibility approach certifications are still under progress and the guide will be amended to develop these points specifically related to the -600 in later revision.

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Contents

Contents Chapter A. General 1. A brief history ........................................................................................................................................................................................................................................8 2. Economic aspects .........................................................................................................................................................................................................................8 3. Low Visibility Operations (LVO) concept...................................................................................................................................................9 3.1. General....................................................................................................................................................................................................................................................9 3.2. Low Visibility Take-Off (LVTO)..................................................................................................................................................................................9 3.3. Category II approaches................................................................................................................................................................................................10 3.4. Category IIIA approaches .........................................................................................................................................................................................10 3.5. Lower than standard Category I operation .......................................................................................................................................10 3.6. Other than Standard Category II operation ......................................................................................................................................10 4. Relevant regulations ..............................................................................................................................................................................................................10 4.1. Aeroplanes certification ..............................................................................................................................................................................................10 4.2. Airfield regulation .................................................................................................................................................................................................................10 4.3. Operational regulation ...................................................................................................................................................................................................11 5. Definitions ...............................................................................................................................................................................................................................................11 5.1. General................................................................................................................................................................................................................................................11 5.2. Categories of precision approach and landing operations ........................................................................................12 5.2.1. Category II (CAT II) .........................................................................................................................................................................................................12 5.2.2. Category IIIA (CAT IIIA) .............................................................................................................................................................................................13 5.2.3. Category IIIB (CAT IIIB) .............................................................................................................................................................................................13 5.2.4. Category IIIC (CAT IIIC).............................................................................................................................................................................................13 5.2.5. Lower than Standard Category I ....................................................................................................................................................................13 5.2 .6. Other than Standard Category II ....................................................................................................................................................................14 5.3. Summary ..........................................................................................................................................................................................................................................14

Chapter B. Revision of low visibility weather conditions 1. The characteristics of fog .............................................................................................................................................................................................16 1.1. Radiation fog ..............................................................................................................................................................................................................................16 1.2. Advection fog .............................................................................................................................................................................................................................17 1.3. Frontal / Precipitation fog .........................................................................................................................................................................................17 1.4. Upslope and valley fogs ..............................................................................................................................................................................................18 2. Effects of precipitation, wind and turbulences ..........................................................................................................................18 2.1. The effect of precipitation ........................................................................................................................................................................................18 2.2. The effect of wind and turbulences .............................................................................................................................................................19 3. Runway Visual Range (RVR)......................................................................................................................................................................................20 3.1. General................................................................................................................................................................................................................................................20 3.2. RVR measurements...........................................................................................................................................................................................................20 3.3. RVR use .............................................................................................................................................................................................................................................22 3.4. RVR practical limitation ...............................................................................................................................................................................................24 3.5. Conversion of reported meteorological visibility to RVR ...............................................................................................24

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4. Weather documentation ..................................................................................................................................................................................................25 4.1. Weather charts .........................................................................................................................................................................................................................25 4.2 TAF/METAR/SPECI ...............................................................................................................................................................................................................26 4.2.1. General .......................................................................................................................................................................................................................................26 4.2.2. TAF ..................................................................................................................................................................................................................................................26 4.2.3. METAR/SPECI .....................................................................................................................................................................................................................27

Chapter C. Aircraft requirements 1. Aircraft certification status .........................................................................................................................................................................................29 1.1. General................................................................................................................................................................................................................................................29 1.2. Guidance and landing systems .........................................................................................................................................................................29 1.2.1. CAT II approaches ..........................................................................................................................................................................................................29 1.2.2. CAT IIIA approaches with DH ≥50ft .............................................................................................................................................................30 1.2.3. Lower than standard CAT I and other than standard CAT II.............................................................................................30 1.2.4. Low visibility take-off ..................................................................................................................................................................................................30 1.3. System performances ....................................................................................................................................................................................................31 1.4. Aircraft Flight Manual content ............................................................................................................................................................................31 2. ATR automatic flight control system...........................................................................................................................................................31 2.1. AFCS on classic instruments ATR .................................................................................................................................................................31 2.2. AFCS on ATR -600 ...............................................................................................................................................................................................................33 3. Aircraft minimum equipment required .....................................................................................................................................................33 3.1. Classic instruments ATR ............................................................................................................................................................................................34 3.2. ATR -600 ............................................................................................................................................................................................................................................34 4. Aeroplane malfunctions ...................................................................................................................................................................................................34 4.1. ATR 72-500.....................................................................................................................................................................................................................................35 4.2. ATR -600 ............................................................................................................................................................................................................................................35 5. Maintenance ........................................................................................................................................................................................................................................36

Chapter D. Airfield requirements 1. Aerodrome approval...............................................................................................................................................................................................................38 2. Runway and taxiway characteristics..........................................................................................................................................................38 2.1. Runway length ..........................................................................................................................................................................................................................38 2.2. Runway width ............................................................................................................................................................................................................................38 2.3. Runway slope ............................................................................................................................................................................................................................38 2.4 Runway-holding position .............................................................................................................................................................................................38 3. Effects of pre-threshold terrain profile....................................................................................................................................................39 4. Obstacles clearances requirements............................................................................................................................................................39 5. Navaids - Characteristics and limitations ..........................................................................................................................................41 5.1. General................................................................................................................................................................................................................................................41 5.2. ILS characteristics ..............................................................................................................................................................................................................41 5.3. ILS performances .................................................................................................................................................................................................................42 5.4. ILS classification ...................................................................................................................................................................................................................43 5.5. ILS protection ............................................................................................................................................................................................................................44 6. Characteristics of the visual aids .....................................................................................................................................................................44 6.1. Runway markings.................................................................................................................................................................................................................44

Contents

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Contents

6.2. CAT II/III Lighting systems .......................................................................................................................................................................................45 6.2.1 Taxiway lights........................................................................................................................................................................................................................46 6.2.2. Stop bars ..................................................................................................................................................................................................................................46 6.2.3. Runway guard lights ....................................................................................................................................................................................................46 6.2.4. Runway lights ......................................................................................................................................................................................................................47 6.2.5. The approach lighting system ...........................................................................................................................................................................47 6.2.6. Lighting system condition .....................................................................................................................................................................................49

6.3. Lighting systems for Lower than standard CAT I and other than standard CAT II approaches ...................................................................................................................................................................................................................................49

7. ATC Procedures.............................................................................................................................................................................................................................50

Chapter E. Flight crew operating procedures 1. General .........................................................................................................................................................................................................................................................52 2. Pre-flight procedures............................................................................................................................................................................................................52 3. On ground procedures and precautions...............................................................................................................................................53 3.1. General................................................................................................................................................................................................................................................53 3.2. Recommended procedures ....................................................................................................................................................................................53 3.2.1. Prior to taxiing ....................................................................................................................................................................................................................53 3.2.2. During taxi...............................................................................................................................................................................................................................53 3.2.3. Prior to approach phase ..........................................................................................................................................................................................54 3.3. Usual difficulties.....................................................................................................................................................................................................................54 3.4. Airport moving map...........................................................................................................................................................................................................55 3.4.1. Electronic Flight Bag (EFB)...................................................................................................................................................................................55 3.4.2. ATR -600 ....................................................................................................................................................................................................................................55 4. Low visibility take-off (LVTO) ...................................................................................................................................................................................55 4.1. General................................................................................................................................................................................................................................................55 4.2. Low Visibility Take-Off under European regulation (EU-OPS) .................................................................................56 5. Approach preparation..........................................................................................................................................................................................................57 5.1. Conditions at destination / at the alternate aerodrome ..................................................................................................57 5.2. Aircraft capability .................................................................................................................................................................................................................57 5.3. Fuel calculation .......................................................................................................................................................................................................................57 5.4. DH setting .......................................................................................................................................................................................................................................58 5.5. Approach briefing.................................................................................................................................................................................................................58 5.6. Cabin crew information................................................................................................................................................................................................58 5.7. Seat position ...............................................................................................................................................................................................................................59 6. Normal procedures for low visibility approaches ..................................................................................................................59 6.1. General................................................................................................................................................................................................................................................59 6.2. Approach ban / RVR controlling ......................................................................................................................................................................59 6.3. Task sharing .................................................................................................................................................................................................................................60 6.4. Normal procedures on classic instruments ATR for CAT II approaches ..................................................60 6.5. Normal procedures and task sharing for CAT III, other than standard CAT II and lower than standard CAT I approaches on ATR -600.......................................................................................................... 64 6.6.Visual segment at DH and minimum visual references......................................................................................................64 6.7. Loss of visual references below DH ...........................................................................................................................................................65

7. Abnormal procedures ..........................................................................................................................................................................................................65 7.1. General................................................................................................................................................................................................................................................65


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7.2. Failure treatment concept ........................................................................................................................................................................................66 7.3. Failure treatment on classic instruments ATR .............................................................................................................................66 7.4. Failure treatment on ATR -600 ............................................................................................................................................................................67 7.5. Maximum ILS deviation allowed ......................................................................................................................................................................67

8. Effects of failure of ground equipment....................................................................................................................................................68

Chapter F. Flight crew training and qualification 1. General .........................................................................................................................................................................................................................................................71 2. Ground training...............................................................................................................................................................................................................................71 3. Simulator training and checking ........................................................................................................................................................................72 3.1. Full training program .......................................................................................................................................................................................................72 3.2. Training for flight crew members with Category II or Category III experience................................74 3.3. Training for flight crew members flying on classic instruments ATR and on ATR -600 .......74 3.4. Flight crew qualification ..............................................................................................................................................................................................74 4. Line training..........................................................................................................................................................................................................................................74 5. Type and command experience ..........................................................................................................................................................................75 6. Recurrent training and checking.......................................................................................................................................................................75 7. The qualification process of flight crew under EASA regulation: overview ...............................76

Chapter G. Operator’s duties 1. Establishing operating minima .............................................................................................................................................................................78 1.1. General................................................................................................................................................................................................................................................78 1.2. EASA take-off minima ....................................................................................................................................................................................................79 1.3. EASA CAT II minima ..........................................................................................................................................................................................................79 1.4. EASA CAT III minima ........................................................................................................................................................................................................79 1.5. EASA Lower than standard CAT I minima ..........................................................................................................................................80 1.6. EASA other than standard CAT II minima ...........................................................................................................................................80 1.7. Operating minima publication.............................................................................................................................................................................81 2. Operations manual content .......................................................................................................................................................................................81 3. Operational demonstration.........................................................................................................................................................................................82 3.1. General................................................................................................................................................................................................................................................82 3.2. Operational demonstration under European regulation .................................................................................................83 3.3. Operational demonstration under FAA regulation ..................................................................................................................84 4. Eligible aerodromes and runways ...................................................................................................................................................................84 5. Continuous monitoring ......................................................................................................................................................................................................85 6. Operator approval process .........................................................................................................................................................................................85 6.1. Prerequisite / transitional period.....................................................................................................................................................................85 6.2. Operational approval file ............................................................................................................................................................................................86 6.3. Sequencing of action during the approval process ..............................................................................................................86

Abbreviations

...............................................................................................................................................................................................................


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A. General

A - General 7B$75B$:2FKDSWHU$WR*PD\LQGG

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A. General

1. A brief history Landing in Low Visibility Conditions was made possible by huge improvements in aircraft automatic control systems over the last 40 years coupled with stringent requirements for airfield equipment and crew qualification. All modern aircraft are now certificated for CAT II operations and many for CAT III operations. CAT II approaches approval has been granted to ATR aircraft at the initial certification in 1985. The new series ATR 42-600 and ATR 72-600 will be certificated for CAT II and CAT IIIA approaches.

Figure A1: ATR aircraft in low visibility conditions at parking

2. Economic aspects There is an overall positive economic impact for the adoption of Low Visibility Operations. In certain regions of the world, the best way for an airline to maintain its schedule all year round without any diversion due to weather, is to be approved to perform Low Visibility Operations. There may initially be a cost implication to implement Low Visibility Operations (CAT II/III equipments, flight crew training...). However, it is the only way to keep in-line services operational throughout the whole year with a minimum number of diversions. Weather conditions mainly depend on the airfield location, nevertheless actual CAT II/III conditions may occur at any airfield depending on the periods of the year. Diversions and delayed flights are expensive for an airline, due not only to passenger compensation costs but also due to the resulting bad “image”. For these reasons, getting operational approval for CAT II/III approaches and Low Visibility Take-Off can be considered as a necessary step in the evolution of a modern airline. There may further be a slight positive environmental impact from a higher landing success rate at destination, plus a consequential reduction in fuel consumption.


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3. Low Visibility Operations (LVO) concept 3.1. General When developing low visibility procedures, the airline objective is to achieve under low visibility conditions both a level of safety and a rate of reliability equivalent to those achieved during normal operating conditions. Take-off and taxing in low visibility conditions involves specific operating procedures and suitable airport installations (runway lighting system, RVR measurement system, ...) but does not require specific on board equipment. Landing in low visibility conditions is made possible using high performances ground ILS equipment together with the onboard receivers and the automatic flight control system of the aircraft. The decision to land is taken in very close proximity to the ground (between 200ft and 0 ft, depending on the category of the approach); pilots see the runway lights only a few seconds before touchdown, therefore there is no margin for error. The desired level of safety is achieved through: – Ground ILS facility, – Airborne equipment, – Visual aids (runway markings, lighting systems), – Flight crew training, – Flight crew procedures, – Air Traffic Control procedures, – Aircraft maintenance, – Airfield maintenance, – Criteria for obstacle clearance. The basic principles governing Low Visibility Operations are that: Q the

aerodrome satisfies the ICAO standards for LVO, including visual and non-visual aids, runway characteristics, obstacle clearance area, RVR measurements, ATC procedures… The aerodrome is approved for such operations by the State in which the aerodrome is located.

Q the

aeroplane is certificated for such operations. Limitations and conditions specified in the Aircraft Flight Manual are respected. The aeroplane and its equipments are maintained in accordance with the approved maintenance manual.

Q each

flight crew member has successfully completed the training and checking program approved by the operator’s Authority.

Q operating

procedures have been established and are applied by flight crew members. Those procedures cover task sharing during Low Visibility Take-Off and approaches and the actions to be taken in case of equipment failure.

Q the

operator has obtained from his national authority an operational approval to perform such operations.

3.2. Low Visibility Take-Off (LVTO) When visibility decreases the pilot must continue to be able to judge the aeroplane’s lateral position to keep it within acceptable limits relative to the runway centre line throughout the take-off roll and eventually during the aborted takeoff phase. The basic information required by the pilot is normally provided by external visual cues but these may be supplemented by instrument derived information. When take-off is performed using only external visual cues, the runway lighting system is essential.


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A. General

3.3. Category II approaches In Category II operations, the ILS precision instrument approach is performed using the automatic flight control system down to below the Decision Height (typically 100ft). At the Decision Height, the visual references should be sufficient to allow the pilot to continue the approach and to perform a manual landing using only external visual cues.

3.4. Category IIIA approaches In Category III the Decision Height and the Runway Visual Range are lower than in CAT II operations. The time from the decision height to the start of the flare is shorter. To preserve the safety level it has been considered necessary that the ILS precision instrument approach be performed using the automatic flight control system right until the aircraft is on the ground. Approach, flare and landing are performed automatically. At the Decision Height, the visual references should be sufficient to allow the pilot to decide if the aircraft will land within the touchdown zone. The main difference between CAT II and CAT III operations is that in Category II conditions the pilot has enough time and sufficient visual references to permit a manual landing, whereas it is not the case when in Category III conditions and an automatic landing has to be performed.

3.5. Lower than Standard Category I operation On aerodromes only supporting Category I approach, the Decision Height can not be lower than 200ft. Nevertheless, depending on the ILS ground equipment performance, the required Runway Visual Range can be lower than the Standard CAT I RVR if the aircraft is equipped with an auto-land system approved for CAT III operations. In order to be authorised to use reduced RVR, the approach must be flown auto-coupled to an auto-land.

3.6. Other than Standard Category II operation Category II or III approach can not be published on aerodromes using limited facilities for approach lighting and runway lighting. On those aerodromes, aircraft able to perform an auto-land can consider the use of a Category II Decision Height (typically 100ft) with an RVR higher than the one of a Standard Category II approach. Such approaches are referred to as other than Standard Category II operation.

4. Relevant regulations 4.1. Aeroplanes certification FAA – Advisory circular AC 120-29A, Criteria for approval of Category I and Category II weather minima for approach – Advisory circular AC 120-28D, Criteria for approval of Category III weather minima for take-off, landing, and rollout – Advisory circular AC 20-57, Automatic Landing Systems

EASA – CS AWO, Certification Specifications for All Weather Operations

4.2. Airfield regulation ICAO – – – –

Annex 14 Volume 1, Aerodrome Design and Operations Annex 10 Volume 1, Radio navigation aids (ILS specifications) PANS-OPS (Doc 8168) Volume 2, Construction of visual and instrument flight procedures Doc 9328, Manual of Runway Visual Range Observing and Reporting Practices


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Other Each State may have its own policy to approve its aerodromes for Low Visibility Operations. Those regulations are not supposed to be less restrictive than ICAO Annexes otherwise differences should be notified.

4.3. Operational regulation ICAO – Annex 6, Operation of Aircraft – Doc 9365, Manual of All Weather Operations

FAA – Advisory circular AC 120-29A, Criteria for approval of Category I and Category II weather minima for approach – Advisory circular AC 120-28D, Criteria for approval of Category III weather minima for take-off, landing, and rollout

EASA – EU-OPS Subpart E, All Weather Operations

Other Each State may have its own operational regulation It is worth noting that harmonisation was conducted between EASA and FAA operational regulations for CAT II and CAT III operations which are now very similar.

5. Definitions 5.1. General All Weather Operations ICAO Doc 9365 – Foreword Any taxi, take-off and landing operations in conditions where visual reference is limited by weather conditions.

Aerodrome operating minima for take-off ICAO Annex 6 – Chapter 1: Definition The limits of usability of an aerodrome expressed in terms of runway visual range and/or visibility and, if necessary, cloud conditions.

Aerodrome operating minima for precision approach and landing operations ICAO Annex 6 – Chapter 1: Definition The limits of usability of an aerodrome expressed in terms of visibility and/or runway visual range and decision altitude/height (DA/H) as appropriate to the category of the operation.

Decision altitude (DA) or decision height (DH) ICAO Annex 6 – Chapter 1: Definition A specified altitude or height in the precision approach or approach with vertical guidance at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. Note: Decision altitude (DA) is referenced to mean sea level and decision height (DH) is referenced to the threshold elevation.


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A. General

According to EASA, the Decision Height for Category II, Category III and other than Standard Category II operations is determined by means of radio-altimeter. For some specific Category II approaches, the FAA gives free choice on DH recognition (radio-altimeter, inner markers or barometric altimeter).

Low Visibility Operations (LVO) For this specific document, LVO includes Low Visibility Take-Off, Category II approaches, Category IIl approaches, other than Standard CAT II and lower than Standard CAT I approaches.

Low Visibility Procedures (LVP) - EASA definition EU-OPS 1.435 Terminology Procedures applied at an aerodrome for the purpose of ensuring safe operations during Lower than Standard Category I, Other than Standard Category II, Category II and III approaches and Low Visibility Take-Offs.

Low Visibility Take-Off (LVTO) - EASA definition EU-OPS 1.435 Terminology A Low Visibility Take-Off is a take off where the Runway Visual Range is less than 400m.

Runway visual range (RVR) ICAO Annex 6 – Chapter 1: Definition The range over which the pilot of an aircraft on the centre line of a runway can see the runway surface markings or the lights delineating the runway or identifying its centre line. NOTE: Category II and Category III instrument approach and landing operations shall not be authorised unless RVR information is provided.

5.2. Categories of precision approach and landing operations 5.2.1. Category II (CAT II) ICAO and FAA ICAO Annex 6 – Chapter 1: Definition AC 120-29A - Appendix 1: Definitions and acronyms A Category II operation is a precision instrument approach and landing with a decision height lower than 60 m (200 ft), but not lower than 30 m (100 ft), and a runway visual range not less than 350 m.

EASA EU-OPS 1.430 - Appendix 1 (new): Aerodrome operating minima (f) A Category II operation is a precision instrument approach and landing using ILS or MLS with a decision height below 200 ft but not lower than 100 ft; and a runway visual range of not less than 300 m. NOTE: For the minimum RVR requested, the EASA definition is slightly different from the ICAO and FAA definitions: not less than 350 m for ICAO and FAA but not less 300 m for EASA.


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5.2.2. Category IIIA (CAT IIIA) ICAO and FAA ICAO Annex 6 – Chapter 1: Definition AC 120-29A - Appendix 1: Definitions and acronyms A Category IIIA operation is a precision instrument approach and landing with a decision height lower than 30 m (100 ft) or no decision height; and a runway visual range not less than 200 m.

EASA EU-OPS 1.430 - Appendix 1 (new): Aerodrome operating minima (g) A Category IIIA operation is a precision instrument approach and landing using ILS or MLS with a decision height lower than 100 ft; and a runway visual range not less than 200 m. NOTE: The ICAO and FAA regulations differ from EASA by considering CAT IIIA approaches with no DH. EASA systematically associates CAT IIIA approaches with a decision height.

5.2.3. Category IIIB (CAT IIIB) ICAO and FAA ICAO Annex 6 – Chapter 1: Definition AC 120-29A - Appendix 1: Definitions and acronyms A Category IIIB operation is a precision instrument approach and landing with a decision height lower than 15 m (50 ft) or no decision height; and a runway visual range less than 200m but not less than 50 m.

EASA EU-OPS 1.430 - Appendix 1 (new): Aerodrome operating minima (g) A Category IIIB operation is a precision instrument approach and landing using ILS or MLS with a decision height lower than 100 ft, or no decision height; and a runway visual range lower than 200 m but not less than 75 m. NOTE: The ICAO and FAA regulations differ from EASA on the minimum RVR associated with CAT III B approaches.

5.2.4. Category IIIC (CAT IIIC) ICAO and FAA ICAO Annex 6 – Chapter 1: Definition AC 120-29A - Appendix 1: Definitions and acronyms A Category IIIC operation is a precision instrument approach and landing with no decision height and no runway visual range limitations.

EASA CAT III C operations are not currently authorised so EASA does not make reference to this sub-category.

5.2.5. Lower than Standard Category I EASA EU-OPS 1.435 Terminology A Category I Instrument Approach and Landing Operation using Category I DH, with an RVR lower than would normally be associated with the applicable DH.


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A. General

5.2.6. Other than Standard Category II EASA EU-OPS 1.435 Terminology A Category II Instrument Approach and Landing Operation to a runway where some or all of the elements of the ICAO Annex 14 Precision Approach Category II lighting system are not available.

5.3. Summary Definitions of Categories of precision approach give the lowest acceptable minima. During operations those values may be limited by aircraft capability, by airfield limitation, by crew individual qualification or by operator’s authorisation.

Lower than stand. CAT I

DH

ICAO

FAA

EASA

–

–

DH ≥200ft

RVR

–

–

400m≤RVR

DH

100ft ≤ DH < 200ft

100ft ≤ DH < 200ft

100ft ≤ DH < 200ft

CAT II

RVR

350m ≤ RVR 1200ft ≤ RVR

350m ≤ RVR < 800m 1200ft ≤ RVR < 2400ft

300m ≤ RVR 1000ft ≤ RVR

Other than stand. CAT II

DH

–

–

100ft ≤ DH < 200ft

RVR

–

–

350m ≤ RVR

DH

No DH or DH < 100ft

No DH or DH < 100ft

DH < 100ft

CAT IIIA

RVR

200m ≤ RVR 700ft ≤ RVR



DH

DH < 50ft or No DH

DH < 50ft or No DH

DH < 100ft or No DH

RVR

50m ≤ RVR < 200m 150ft ≤ RVR < 700ft

50m ≤ RVR < 200m 150ft ≤ RVR < 700ft

75m ≤ RVR < 200m 250ft ≤ RVR < 700ft

DH

No DH

No DH

–

RVR

No RVR limitation

No RVR limitation

–

CAT IIIB

CAT IIIC

Table A1: Summary of approach category definitions, in accordance with ICAO, FAA, and EASA Regulations

ICAO Annex 6 – Chapter 1: Definition

Note: Where decision height (DH) and runway visual range (RVR) fall into different categories of operation, the instrument approach and landing operation would be conducted in accordance with the requirements of the most demanding category (e.g. an operation with a DH in the range of CAT IIIA but with an RVR in the range of CAT IIIB would be considered a CAT IIIB operation or an operation with a DH in the range of CAT II but with an RVR in the range of CAT I would be considered a CAT II operation). Acceptable operational correspondance meter/feet (according to ICAO) 15m = 50ft 30m = 100ft 50m = 150ft 100m = 300ft 150m = 500ft 175m = 600ft 300m = 1000ft 350m = 1200ft 500m = 1600ft 600m = 2000ft 800m = 2400ft 1000m = 3000ft 1600m = 5000ft

75m = 250ft 200m = 700ft 550m = 1800ft 1200m = 4000ft


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B. Revision of low visibility weather conditions

B - Revision of low visibility weather conditions 7B$75B$:2FKDSWHU$WR*PD\LQGG

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1. The characteristics of fog Although visibility may be reduced by the presence in the air of solid particles such as smoke, dust or sand, most of the time low visibility conditions are caused by fog. There is fog if the visibility is less than 1000m and the obscuring agent is water droplets. Fog differs from rain or mist in that its water particles are more minute and suspended and do not fall earthward. The droplets of water suspended in the air near the earth’s surface act on scattering the light and thus reduce the visibility near the ground. The formation of a fog layer occurs when a moist air mass is cooled to its saturation point (dew point): the water vapor within the air mass condenses on small particles in the air to form liquid cloud droplets. This cooling can be the result of: – radiative processes (radiation fog), – advection of warm air over cold surfaces (advection fog), – evaporation of precipitation (precipitation or frontal fog), – movement of humid air up or down the hillside (upslope fog or valley fog).

1.1. Radiation fog Radiation fog is caused by the radiation cooling of earth’s surface. After sunset, earth receives no heat from the sun, but its surface continues to reradiate heat. The surface begins to cool because of this heat loss. As the Earth cools, the layer of air adjacent to the surface is cooled by conduction. This causes the layer near earth to be cooler than the air immediately above it, a condition called an inversion. If the air beneath the inversion layer is sufficiently moist and cools to its dew point, fog forms. In case of a calm wind and since air is a poor conductor of heat, this cooling by conduction affects only a very shallow layer i.e. a few inches deep. Wind of low speed (3 to 5 knots) causes slight, turbulent currents. Such turbulence is enough to spread the fog through deeper layers. As nocturnal cooling continues, the air temperature drops further, more moisture is condensed, and fog becomes deeper and denser. If wind speed is between 5 and 10 knots then the fog will usually thicken vertically. Winds greater than 10 knots usually result in the formation of low scud, stratus, or stratocumulus. At sunrise, the Earth is heated. Radiation from the warming surface heats the lower air, causing an evaporation of the lower part of fog, thereby giving the appearance of lifting fog. Before noon, the radiated heat from the warming of the earth surface destroys the inversion process, so then the fog evaporates into warmed air. Radiation fog appears over land, it never forms over a water surface and it may cover a wide area. The conditions giving rise to the formation of radiating fog are: – cloudless nights, allowing the earth to lose heat by radiation, – moist air that requires a little cooling to reach the dew point temperature, – light winds (5-7kts) to mix the lower layers of air, thereby thickening the fog layer. Such conditions are common in high-pressure areas during autumn and winter in temperate zones. Further radiational cooling at top of fog layer, deepens it.

Heat radiating from the surface at night, cools the bottom air until it reaches saturation.

Fog forms first at the surface, thickening as cooling continues. Figure B1: Radiation fog


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1.2. Advection fog Advection fogs are formed when air moves either over a cooler surface or over a warmer moist surface and, as a result, the air mass reaches saturation. Most often this occurs when a moist air mass moves over a cold surface with a temperature lower than the dew point of the moving air. Cooling from below takes place and gradually builds up a fog layer. The cooling rate depends on the wind speed and the difference between the air temperature and the temperature of the surface over which the air travels. A low wind speed heightens the likelihood as the air remains in contact with the surface long enough to sufficiently cool the air layer. Advection fogs are often persistent since the weather situation that forms them can last a day or more. Usually, either a frontal passage with a change of air-mass or a major change in wind direction are needed for the dissipation of advection fog.

Fog forms

Colder surface

Warmer, moist air moves over a colder surface and its temperature drops Figure B2: Advection fog

1.3. Frontal / Precipitation fog This fog type is due to the evaporation of falling rain and occurs under the frontal surface in the cold air mass. Precipitation falls from the lifted warm air through the cold air. Evaporation from the rain continues as long as the raindrop temperature is higher than the temperature of the air, even though the cold air is already saturated. Naturally, the upper regions become saturated first because, at higher altitude, both the temperature and dew point are lower. As rain evaporation continues, a layer of clouds begins to build down from the frontal surface. Eventually, this cloud layer extends to the ground turning into fog. Cold fronts usually move so rapidly and have such narrow bands of precipitation and high wind speeds that a cold front fog is comparatively rare and short lived. A warm front fog, on the other hand, is fairly common. Warm-front fog may cover a wide area. Also this type of fog is deep because it extends from the ground to the frontal surface. precipitation falls through warm air rain cloud warm air

front cold air

fog evaporation leads to saturation

Figure B3: Frontal fog


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1.4. Upslope and valley fogs Upslope fog is caused by adiabatic cooling of rising air. When moist, warm air is forced to move over a terrain obstacle, it cools to some degree as it rises, the degree of cooling depending on the amount of rise. During that cooling, if the air temperature falls below dew point, the resulting condensation will form a cloud. The air must be stable before it starts its motion, so that lifting does not cause convection, nor vertical currents, which would dissipate the fog. Wind speed is needed, of course, to cause upslope motion. This type of fog is deep and requires considerable time to dissipate.

Fog forms on slope.

Moist air flows toward slope.

As air rises with the terrain, it cools to condensation temperature. Figure B4: Upslope fog

Valley fog forms during the evening as a result of air being cooled by radiation on slopy topographical features. As this air becomes denser than its surroundings, it starts going down the slope. This results in the creation of a pool of cold air at valley floor level. If the air is cold enough to reach its dew point, fog formation occurs. Air cools at higher elevations. Fog forms in valley

Cold air drains downslope into valley.

Cold air drainage reduces air temperature in valley to condensation point. Figure B5: Valley fog

2. Effects of precipitation, wind and turbulences 2.1. The effect of precipitation Precipitation includes drizzle, rain, snow, ice crystals and hail. Although liquid precipitation on windshields can be a serious irritation for pilots, it does not seriously limit visibility, except when rain or drizzle is associated with fog. Even heavy rain does not usually limit visibility to less than 1 km.


p. 18

Figure B6: View from windshield during precipitation

Snow fall is a different matter; a very light snowfall alone can reduce visibility considerably. As snowfall becomes heavy, visibility may drop to only a few meters. Blowing snow is to be expected when loose snow is raised by the wind. The limited visibility may extend to a considerable height. This problem is quite significant in cold climates. Snow also affects approach and runway lighting intensity, thus reducing the chances of acquiring visual cues at Decision Height. Furthermore, the actual visibility may be less than the horizontally measured visibility because of the lack of contrast between the approach lighting and the snow-covered ground.

Figure B7: Snowy environment

2.2. The effect of wind and turbulences Low visibility conditions are usually due to the presence of fog which often appears in anticyclones. Therefore most of the time CAT II and CAT III approaches are performed with light or moderate wind, except on a limited number of airports where specific conditions may associate fog and strong wind. For CAT II operations, the ATR flight manual states the maximum “demonstrated wind”. It corresponds to the worth wind conditions encountered during certification flight tests. Therefore it should not be considered as a limitation. It is the operator’s responsibility to set the limit as per his national operational regulations. CAT III operations are constrained in respect of the wind component. Unlike the demonstrated wind for manual landings, the autoland wind capabilities are always limiting. The maximum crosswind values for auto-land operations are often less than the manually demonstrated crosswind landings.


p. 19

effect of tailwind: in some airports, not all runways are equipped for cat II/III operations. Therefore in low visibility conditions, a runway may be in use in spite of a light tail wind. The main consequence is a higher ground speed, reducing the time between DH and touchdown. During CAT II approaches, the pilot has less time to take control of the aircraft after the auto pilot disconnection.

Q The

effect of crosswind: At decision height the pilot may have more difficulties to acquire the visual references which are not located on the aircraft axis. Before Decision Height, according to the drift resulting from the crosswind, the pilot has to anticipate where to search visual cues. In CAT III operations the ATR autoland system performs the de-crab but does not follow the runway axis when the aircraft is on ground (no roll out function).

Q The

effect of turbulences: turbulences will increase the pilot’s workload to maintain the approach speed within acceptable limits. In case of severe turbulences, there is also a risk of autopilot disconnection, leading to a missed approach.

3. Runway Visual Range (RVR) 3.1. General The Runway Visual Range (RVR) is an instrumentally derived value that represents the horizontal distance a pilot may see down the runway. It is the maximum distance at which the runway markings or the runway lights can be seen by the pilot of a lined up aircraft. The purpose of RVR is to provide pilots and air traffic services with information on runway visibility conditions during periods of low visibility. ICAO Doc 9328 Chapter 11, Transmission and reporting practices, states the following practices for RVR reporting: – RVR must be assessed on all runways intended for Categories II and III approaches. – Where RVR assessments are required, they should be made and reported throughout periods when either the visibility or the RVR is observed to be less than 1500m. – The lower limit of the reporting range should be 50 m and the upper limit should be 2000 m. – The reporting increments should be 25 m up to 400 m RVR, 50 m between 400 and 800 m RVR, 100 m for values of RVR above 800 m. – The measurements should be averaged over a period of one minute.

3.2. RVR measurements The RVR value is determined by calibrated instruments (i.e. transmissometer or forward scatter meter) located alongside and higher than the centre line of the runway. A transmissometer measures the transmittance of the atmosphere between two points in space, over a specified path length or baseline. It consists essentially of a transmitter that directs a beam of light at a photo detector in a receiver unit. receiver

transmitter optical axis

height mini: 1.50 m maxi: 1.00 m


Q The

measurement reference = 30.00 m

electronic box frangible post data concentrator optical fibres link

Figure B8: Transmissometer principle


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A scatter meter estimates the extinction coefficient by measuring the flux scattered from a light beam by particles present in the atmosphere. It consists of a transmitter and a receiver spaced by about one meter.

Transmitter

Receiver

Figure B9: Forward scatter meter principle

RVR is calculated taking into account the measured quantity (i.e. transmittance or extinction coefficient), the characteristics of the lights and the expected detection sensitivity of the pilot’s eye under prevailing conditions of background luminance.

Figure B10: Transmissometer

Figure B11: Forward scatter meter

The RVR measurement system includes: – instruments (transmissometers or scatter meters), – background luminance sensor: it measures the brightness of the background, against which the pilot would view the runway lights, – a runway light intensity monitor: it provides information on runway light setting, – RVR computer (dedicated or part of the integrated observing system), – digital displays of RVR in the appropriate Air Traffic Services unit, – a recorder to archive data over a given period of time.


p. 21


Figure B12: RVR measurement

The visibility sensors are strategically located along the runway to provide RVR measurements associated with three basic portions of a runway: – the touchdown zone (TDZ), located about 300m from the threshold – the mid-runway portion (MID), located at a distance of 1000 m to 1 500 m from the threshold – the rollout portion or stop end located at a distance of about 300 m from the end of the runway NOTE: For runways less than 2400m, RVR is normally provided for TDZ and Rollout only. The lateral position of the sensors should be within 120m of the runway centreline and the height above runway should be approximately 2.5 m. In certain conditions the RVR may be measured by the pilot or other weather observers. Typically the RVR may be evaluated by the pilot at take-off position, by counting the number of either the runway edge lights or the centreline lights that are visible.

3.3. RVR use Operating minima are expressed in terms of DH and RVR for approach and landing but exclusively in terms of RVR for take-off (please refer to Paragraph G.1, Establishing operating minima). Before commencing a take-off or an approach to land, the crew must satisfy itself that the RVR reported by air traffic services is equal to, or better than, its operating minima.

Take-off The minimum RVR required for a take-off should provide the pilot with sufficient visual references to control the aeroplane until it is airborne, or until the end of an abandoned take-off. This minimum RVR value is to be compared to the reported RVR which represents the visual segment available at the take-off position.

Approach and landing For approach and landing, the minimum RVR associated to a Decision Height is intended to provide a high probability that the required visual references will be available at that decision height. The visual references required (please refer to Paragraph E.6.6, Visual segment at DH and minimum visual references) at and below DH depend on the nature of the task the pilot has to carry out (manual landing or monitoring of an autoland). The reported RVR is an horizontal measure made on the ground while the pilot will normally be looking along a slant path at approach Iights. It is probable that the fog will be less dense at ground level than it is above ground level and slant visibility will probably be Iess than the horizontal visibility at ground level too. Thus, the most relevant information for the pilot is the slant visual range (SVR); however, as practical methods of measuring SVR have not yet been developed, only the RVR measurement is made available.


p. 22

9=9

3PTP[VM ]PZPVU

3PTP[VM ]PZPVU

:=9

Figure B13: RVR and SVR

A geometrical relation can be used to compute the SVR required for the pilot to visually acquire the specified visual segment in relation to the obscured segment. There exist a number of models to convert required SVR into required RVR. They take into account the increase of fog density with the height and they provide SVR/RVR ratios as a function of eyes height. It is then possible to compute a minimum RVR as a function of the DH and of the required visual segment.

7PSV[L`LZM[

WP[JO /VYPaVU[HSYLMLYLUJL *\[VMM HUNSL

M[T

:=9 :LNTLU[VIZJ\YLK M[T

=PZ\HSZLNTLU[

Figure B14: Visual and Obscured segment

SVR / RVR

1 0,9 0,8 0,7 0,6 0,5 0,4 0

25

50

75

100

125

150

175

Pilot’s eyes height (ft) Figure B15: Evolution of SVR/RVR ratio depending on height

Even if such methods enable to deal with the DH/RVR relationship in respect of Category II and III operations, the minimum RVR values set in most current operational regulations have been established by also taking into account various real-life operating experiences which have given satisfactory results over a long period. However it is worth noting that these RVR values, published in tables of operating minima, on their own, have no intrinsic meaning; they have significance only in conjunction with a set of operating policies and procedures.


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3.4. RVR practical limitation The reported RVR is an instrumentally derived value that has significant limitations. It can be greater than, or less than, the actual visibility available to a pilot’s eye. None of the values measured on the ground can accurately indicate whether or not the pilot will have the required visual reference when at decision height. Main error conditions are as follows: – RVR is measured horizontally while the pilot is looking along a slant path, – unusual daylight, such as when a runway is aligned with a sunrise or sunset conditions in shallow or patchy fog, – spatial variations in the weather phenomenon between the pilot‘s view and the location where the RVR is measured (e.g. patchy fog or obscuration varying rapidly in time), – measurement errors from the sensor measuring the extinction coefficient or the transmittance, – angular and temporal variations in light intensity, – differences between the actual and assumed runway light intensity, – differences in background luminance between the pilot‘s view and the direction where the background luminance is measured, or errors in background luminance measurements.

Figure B16: Distorted vision through the windshield

Figure B17: Shallow or patchy fog

Furthermore, when assessing RVR, no account is taken of the effects on the pilot‘s vision of factors such as: – the transmittance of the windshield of the aircraft, – rain on the windscreen, – the level of cockpit lighting, – the illumination to which the pilot has been exposed prior to take-off or landing such as apron floodlighting, very bright fog and flying over bright approach lights, – physical and psychological conditions, e.g. tiredness or stress.

3.5. Conversion of reported meteorological visibility to RVR On aerodromes where there is no instrument to measure the RVR, the only information transmitted to the pilot by Air traffic services is the meteorological visibility. To compare the transmitted value to his operating minima (expressed in terms of RVR), the pilot needs to convert the reported meteorological visibility into RVR. This conversion is prohibited for CAT II and CATIII operations. For other types of operations, the regulatory Authorities usually specify the rules for such conversion.


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For example the European regulation states that: EU-OPS 1.430 - Appendix 1 (new): Aerodrome operating minima (l) Conversion of reported meteorological visibility to RVR/CMV. An operator must ensure that a meteorological visibility to RVR/CMV conversion is not used for take-off, for calculating any other required RVR minimum less than 800m, or when reported RVR is available. (…) In all other circumstances an operator must ensure that the following Table is used: Lighting elements in operation

RVR/CMV= Report Met Visibility x Day

Night

Hi approach and runway lighting

1.5

2

Any type of lighting installation other than above

1.5

1.5

1

Not applicable

No Lighting

Note: If the RVR is reported as being above the maximum value assessed by the aerodrome operator, e.g. “RVR more than 1 500 meters”, it is not considered to be a reported RVR in this context and the Conversion Table may be used. Amongst the Low Visibility Operations covered by this document, only lower than Standard CAT I is concerned by this conversion.

4. Weather documentation During flight preparation the weather document analysis should enable the flight crew to identify or assess the risk of encountering low visibility conditions.

4.1. Weather charts Weather charts cover a large area and are not intended for detection of low visibility condition on a specific airport, nevertheless significant weather symbols inform where visibility reducing weather phenomena are likely to appear. Such information allows the crew to anticipate weather degradation and to be prepared to face low visibility conditions. 'UL]]OH +DLO 5DLQ 6HYHUHVDQGRUGXVWKD]H 6KRZHU 6QRZ :LGHVSUHDGEORZLQJVQRZ :LGHVSUHDGIRJ :LGHVSUHDGKD]H :LGHVSUHDGPLVW :LGHVSUHDGVDQGVWRUPRUGXVWVWRUP :LGHVSUHDGVPRNH Figure B18: Symbol of weather phenomena affecting visibility


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4.2 TAF/METAR/ SPECI The Information provided in the following paragraphs is voluntarily limited to elements affecting visibility.

4.2.1. General A METAR states the weather observed on an aerodrome during the last 10 minutes prior to the observation time. It is issued twice every hour. At some airports it may be issued only once an hour. If the weather changes significantly from the last METAR a special observation report (SPECI) is issued. The TAFs are meteorological forecasting at airport. It is worth noting that RVRs are never forecasted and thus never included in TAF messages. Only the horizontal meteorological visibility is provided. Range and resolution of visibility in TAF, METAR and SPECI: Horizontal visibility range

Resolution

Vertical visibility

Resolution

0000 m – 0800 m

50 m

VV000 – VV020

100ft (e.g. 160ft → VV001; 2000ft → VV020)

0800 m – 5000 m

100 m

VV ///

No vertical vis at all

5000 m – 10000 m

1000 m

Weather phenomena affecting visibility are reported into TAF METAR and SPECI using the following information.

Forecast weather abbreviations DZ RA SN SG IC PL GR

drizzle rain snow snow grains ice crystals (diamond dust) ice pellets hail

GS small hail and/or snow pellets BR mist FG fog FU smoke VA volcanic ash DU widespread dust

SA HZ PO SQ FC SS DS

sand haze dust/sand whirls (dust devils) squall funnel cloud(s) (tornado and waterspout) sandstorm duststorm

Examples + SHRA FZDZ + TSSNGR

heavy shower of rain moderate freezing drizzle thunderstorm with heavy snow and hail

TSSN SNRA

thunderstorm with moderate snow moderate snow and rain

4.2.2. TAF Below is a TAF message typical of CAT II conditions forecasting:

LFBO

150500Z

Airport identification

Day of issue 15 at 05TU

150615

36003KT

0500

Validity: the 15th between 06 and 15 TU

Wind 360° 03kt

Visibility: 500m

FZFG

Cloud layout 200ft

Weather: freezing fog


OVC002

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4.2.3. METAR / SPECI Below is a METAR typical of CAT III conditions:

LFBO

191050Z

Airport identification

01002KT

0200

Wind: 010°, 02kt

Day of issue 19 at 10h50 z

FZFG

R14R0250D

OVC001

Weather: RVR RWY Freezing fog 14R = 250m downgrading

Visibility 200m

M02/M02

Q1025

AOT= –2°C Dew point= –2°C

Cloud layout: 100ft

QNH

Other information on reported RVR in METAR (cf. ICAO Annex 3): – the RVR reported in a METAR is a value averaged over a period of 10 minutes, – only the representative value of the touchdown zone is reported in METAR, – in METAR, the runway visual range should be based on the maximum light intensity available on the runway, – whenever RVR changes and passes through 150, 350, 600 or 800m a report of special observations (SPECI) is issued. R16L/0350

R for RVR Runway 16 Left (C: center R right) RVR 350 meters

R16C/M0050

M means RVR is below the minimum value that can be determined by the system in use (i.e 50m)

R14L/P2000

P means RVR is above the maximum value that can be determined by the system in use (i.e.2000m)

R20/0400V0800

V means that during the averaging period of 10 minutes RVR has varied between 400m and 800m

R12/0550N R20/800D

“U” or “D” are used when during the averaging period of 10 minutes the variation of the RVR shows an Upward or Downward tendency. The abbreviation “N” indicates there is no distinct tendency Table B1: Description of the RVR in METAR

In a METAR, the present weather phenomena (i.e. FG or SN) may be associated with the following information: MIFG

Shallow – less than 2m above ground level.

BCFG

Patches – fog patches randomly covering the aerodrome.

PRFG

Partial – a substantial part of the aerodrome covered by fog while the remainder is clear.

DRSN

Low drifting – snow raised by the wind to less than 2 m above ground level.

BLSN

Blowing – snow raised by the wind to a height of 2 m or more above the ground.

VCFG

Vicinity – Fog reported between approximately 8 and 16 km of the aerodrome reference point.

The OAT / dew point is an interesting indicator: fog usually forms when the dew point and the air temperature are within a few degrees of each other, with the air temperature being lowered to the dew point, or when the dew point being increased to the air temperature causes fog formation. Contrarily, fog would be lifting when the temperature-dew point spread begins increasing.


p. 27

C. Aircraft requirements

C - Aircraft requirements 7B$75B$:2FKDSWHU$WR*PD\LQGG

p. 28

1. Aircraft certification status 1.1. General The basic rule for an aeroplane is to be operated under a current certificate of airworthiness and to be maintained in a serviceable condition, in accordance with an approved maintenance program. Instruments and equipment for Category II and Category III operations have to comply with specific airworthiness requirements. It is assumed that the aircraft has a basic airworthiness approval for IFR operations. The supplementary airworthiness requirements for CAT II operations are described in appendix 3 of AC 120-29A (FAA regulation) and in subpart 2 of CS-AWO (European regulation). For CAT IIIA operations the relevant regulations are Appendix 3 of AC 120-28D (FAA) and subpart 3 of CS AWO (European regulation). To perform lower than Standard CAT I approaches under European regulation, the aeroplane has to be certificated in accordance with CS-AWO to conduct Category II operations and the auto-land system shall be approved for Category IIIA operations. For other than Standard Category II operations under European regulation, the aircraft has to be certificated in accordance with CS-AWO for operations with a decision height below 200ft. The certification process is to demonstrate that a high safety level and an acceptable rate of missed approaches are achieved during low visibility approaches. Such demonstration can be done examining: – airborne system accuracy, – airborne system availability and integrity, – reliability of the airborne equipment, – degree of redundancy, – probability of airborne system failure and consequences. The safety level must not be less than the average safety level achieved in Category I precision approaches. The rate of approaches terminating in a go-around below 500ft, due to the approach and landing system performance or reliability, may not be greater than 5%.

1.2. Guidance and landing systems Aircraft equipped with head up guidance landing system (HUDLS) or enhanced/synthetic vision systems or hybrid system (e.g.; autoland system in combination with head up display system) can be certificated to perform CAT II, CAT IIIA, lower than Standard CAT I and other than Standard CAT II approaches. As ATR aircraft are not equipped with HUDLS the following paragraphs do not deal with those systems.

1.2.1. CAT II approaches An aircraft cannot be approved to perform CAT II approaches without being fitted with an approach guidance system, composed of the following equipment and functions: – two ILS and/or two MLS receivers, – an automatic approach coupler with an audible warning of automatic pilot failure or a flight director system, – one radio altimeter with display at each pilot’s station of radio altitude and the selected decision height, – an indication, at each pilot’s station, of when the aeroplane reaches the pre-selected decision height appropriate to the approach (e.g. an alert light), – an automatic or flight director go-around system, – an appropriate equipment failure warning system, – an alert, at each pilot’s station, on excess deviation from the required approach path. NOTE: FAA regulation authorises flight director CAT II approaches. For EU operational regulation, only auto-coupled CAT II approaches are considered. Classic instruments ATR aircraft are certificated for CAT II approaches providing MOD (1112) is applied. MOD (0069) allows the use of the auto-pilot down to 50ft (MOD 0069 is not available for ATR 42-500).


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AIRCRAFT

MOD

NAME

SB

42-300 72

0069

AUTOFLIGHT – AFCS: USE A CAT II APPROVED AP/FD DOWN TO 50 FT

42-22-0017 72-22-1006

All

1112

AUTOFLIGHT – RETROFIT CAT II CAPABILITY TO A/C DELIVERED WITH CAT I CAPABILITY

42-22-0001 72-22-1007

Basically, ATR -600s are CAT II certified.

1.2.2. CAT IIIA approaches with DH ≥50ft An aircraft approved to perform automatic CAT IIIA approaches (with DH ≥ 50ft) is basically fitted with an automatic approach and landing system including the equipment and functions listed above for CAT II approaches plus: – an automatic voice system, which calls when the aeroplane is approaching the decision height and when it reaches the decision height, – a fail-passive or fail-operational automatic landing system, – an acceptable speed control device or an automatic throttle control. An automatic landing system is fail-passive if, in the event of a failure, there is no significant out-of-trim condition or deviation of flight path or attitude but the landing is not completed automatically. For a fail-passive automatic landing system the pilot assumes control of the aircraft after a failure (cf. CS-AWO 300 Applicability and Terminology (b)(3)). Fail-passive landing system can support CAT IIIA approaches with DH ≥ 50ft, but cannot support CAT IIIB approaches nor CAT IIIA approaches with DH<50ft. An automatic landing system is fail-operational if, in the event of a failure below a specified height, the approach, the flare and landing can be completed by the remaining part of the automatic system. In the event of failure, the automatic landing system will operate as a fail-passive system (cf. CS-AWO 300 Applicability and Terminology (b)(4)). Fail operational landing system are requested for CAT IIIB approaches and CAT IIIA approaches with DH<50ft. Out of the ATR family of aircraft only the ATR -600 is equipped with a fail-passive automatic landing system and a speed control system. Only the ATR -600 can be certificated for CAT IIIA approaches with DH ≥50ft. ATR aircraft are not equipped with fail-operational landing systems nor automatic throttle controls, nor automatic ground roll controls, hence they cannot be certificated for CAT III approaches with DH<50ft.

1.2.3. Lower than Standard CAT I and other than Standard CAT II One of the conditions for an aircraft without HUDLS to be authorised for such operations is to perform an automatic landing. Only aircraft certificated to conduct Category II approaches and equipped with an auto-land system can perform lower than Standard CAT I or other than Standard CAT II. Since ATR -600s are equipped with an automatic landing system they can support lower than Standard CAT I and other than Standard CAT II operations.

1.2.4. Low visibility take-off As long as take-off is performed using only external visual references, even in low visibility conditions, there is no need to satisfy additional certification requirements. The operational regulation, which may vary from one State to another, sets the minimum RVR conditions in which the pilot may be expected to have available the external visual references required for the control of the aeroplane until it is airborne, or until the end of an abandoned take-off (e.g. 125m RVR for European regulation). This RVR limit may be lowered if the aircraft is equipped with a guidance system which provides directional guidance information to the pilot during the take-off or abandoned take-off (e.g. HUD). This guidance information normally takes the form of command information, but it may alternatively be a situation (or deviation) information. In the event of loss of visibility during the take-off or abandoned take-off, the system enables the pilot to control the aeroplane on the runway centreline using the normal steering controls. With the operational benefits provided by such devices being limited (e.g. RVR limit reduced from 125m to 75m), ATR aircraft are not equipped with such a guidance system for take-off, hence they are not required to be subjected to additional certification process.


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1.3. System performances During the certification process, a level of performance, integrity and availability must be demonstrated by a combination of simulator tests, statistical analysis and flight tests. The test conditions must be representative of operative conditions and they must cover the range of parameters affecting the behaviour of the aeroplane (e.g. wind speed, ILS ground facility characteristics, aerodrome elevation and temperature, ground profile, aeroplane configuration, weight, CG…). In addition, an analysis of failure conditions and their effects has to be carried out, including not only failures of the guidance and landing system but also failures of other aeroplane equipment. The aim of this guide is not to describe in details the airworthiness requirements which vary according to the type of operations and to the regulation applied. Nevertheless it is to be noted that, in CAT II certification, particular attention is given to the ILS tracking performances. The probability that the maximum ILS deviation does not exceed the excess deviation alerts has to be demonstrated as being satisfied. In CAT III, the autoland system performances have to be evaluated. Notably it must be shown that the touchdown performance is such that any of the following events is improbable: – longitudinal touchdown earlier than a 60 m from the threshold point on the runway, – longitudinal touchdown beyond the end of the touchdown zone lighting (900 m from threshold), – lateral touchdown with the outboard landing gear more than 21 m (70 ft) from runway centreline (this value assumes a 45 m (150 ft) runway), – sink rate for structural limit load, – bank angle resulting in hazard to the aeroplane and – lateral velocity or slip angle for structural limit load.

1.4. Aircraft Flight Manual content The certification process for Low Visibility Operation leads to specific statements in the Aircraft Flight Manual covering the following items: – Limitations, take-off and approach capacity, including the minimum decision height to which the aeroplane is certificated; – Permitted configurations (e.g. flap setting, number of operating engines); – Normal and abnormal procedures; – Changes to the performance information, if necessary (e.g. approach speed, landing distance required, goaround climb); – Minimum required equipment and effect of failures on aircraft capacity; – The height losses for go-around initiation heights below 30m (100ft). – The maximum head, tail and cross wind components in which the performance of the aeroplane has been demonstrated. NOTE: Actual RVR minima to be used are subject to operational regulation and may vary from one state to another taking account of local circumstances. For this reason, RVR minima should not be included in the Aeroplane Flight Manual as Limitations. With the ATR family, limitations depend on type (42 or 72), on series and modifications applied. Example:

Limitation for ATR 72-500 (please refer to AFM 7.01.03, CAT II operation): Minimum height for use of autopilot in approach mode: 80ft (50ft for MOD 0069) Minimum decision height: 100ft Certified configuration: flaps 30 Maximum demonstrated wind: Headwind: 30kts, tailwind: 10kts, crosswind: 15kts

2. ATR automatic flight control system 2.1. AFCS on classic instruments ATR The Automatic Flight Control System is made up of the following components: – one computer – one advisory control panel – one control panel – three servo-actuator (one for each axis)


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ADVISORIES

SELECT LT

MESSAGES ARMED MODE CAPTURED MODE

ADU

AFCS CONTROL PANEL

AFCS COMPUTER

QUICK DISC/ TCS

QUICK DISC/ TCS

Figure C1: Classic ATR AFCS description

The computer receives data from several sensors and generates commands to the flight control actuators and to the FD bars. Dual microprocessor architecture and digital servo-monitoring techniques are used to provide an adequate safety level. In ILS approach mode, LOC and GS are displayed both on ADU and on EADI: – In white during the arm phase LOC – In green with a star during the capture phase LOC* – In green without star when in track phase LOC . Track phase, for both LOC and G/S, can only take place below 1500ft RA, but must be achieved before 800ft RA.

Category II capability As soon as APP mode is armed, the approach capability (as seen by the AFCS computer), will be displayed on the first line of the ADU (CAT 1 or CAT 2) CAT2 message means that CAT II conditions are met; it replaces the CAT1 message on ADU as and when all the following requirements are satisfied: – Pilot and copilot AHRS valid – Pilot and copilot EFIS valid – Pilot or copilot DADC valid


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– Radio altitude 1 or radio altitude 2 valid – Pilot and copilot displaying an ILS source – Radio altitude greater than 800 feet AGL – Comparison monitor annunciator is non-active.

Figure C2: CAT 2 display on ADU

The CAT2 message remains displayed for the duration of the approach if all the above stated conditions remain satisfied. If any of those requirements for the CAT2 message are lost, a CAT2 INVALID message flashes on the ADU. In addition a triple click aural warning is generated. Excess Deviation monitoring utilizes ILS data from both SGU and is enabled when CAT II conditions are met.

Dual coupling During ILS approach, DUAL coupling automatically occurs after LOC and GS track phase has begun, if only if both NAV receivers are tuned to ILS. In dual CPL both arrows are illuminated and both NAV receivers are coupled to the AFCS computer which utilizes average data for guidance computation. Dual coupling requires that all of the following conditions are met. – The EHSIs are displaying different ILS navigation sources tuned to the same frequency – Both the localizer and glideslope are in track mode – Radio altitude is below 1200 feet AGL – Both navigation receivers are operative.

Figure C3: CPL on AFCS control panel

2.2. AFCS on ATR -600 For later revision.

3. Aircraft minimum equipment required The equipment which must be serviceable at the beginning of the approach is established during the certification process and included in the AFM. This list should be used to amend the airline Minimum Equipment List (MEL). The dispatch conditions for relevant equipment should clearly indicate that CAT II or CAT III operations are not authorised. This list should also be included in the airline operating manual and/or QRH to be used by the crew mainly in case of in flight failure. Before commencing a low visibility approach the crew has to check that all relevant equipment is operative.


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3.1. Classic instruments ATR Below is the minimum equipment required on ATR 72-500 to meet CAT II approach criteria (please refer to AFM 7.01.03, CAT II operation).

Equipment required: Autopilot FD bars AP quick disconnect AP OFF warning (light and aural)

1 1 (PF side) 1 (PF side) 1

ADU ILS receiver AHRS Standby Horizon CRT SGU Radio altimeter DH indicator GA pushbutton Windshield wipers Yaw damper Airspeed indicators

1 2 2 1 3 (2 PF side) 2 1 (with 2 displays) 2 1 (PF side) 1 (PF side) 1 2 CM2 side must be operative(1) CM1 side must be operative, if CM1 is PF 3 Blue + Green DC: BUS 1 / BUS 2 / EMER / STBY / ESS AC: BUS 1 / BUS 2 / STBY ACW: BUS 1 / BUS 2 3

Altimeter Hydraulic system Electrical system

MFC modules (1)

The standby airspeed instrument can be easily monitored only from the Captain position.

In addition to this list it is worth noting that in case of engine failure on ATR, although the autopilot can be engaged during approach, CAT II approaches are not authorised.

3.2. ATR -600 For later revision.

4. Aeroplane malfunctions During the CAT II/III certification process, the analysis of failure conditions and their effects will determine the actions to be taken by the flight crew in case of failure of any system, instrument, or element during a low visibility approach. The nature of the failure and the point of its occurrence determine which response is appropriate. In general there are three possible responses to a failure: – CONTINUE the approach to the planned minima, – REVERT to higher minima and proceed to a new DH, – GO AROUND and reassess the capability. The appropriate actions to be taken in case of failure are provided by the Aircraft Flight Manual. The procedures following failure, established by the operator and published in his Operating Manual, should not be less restrictive than those of the AFM. Here below are listed the failures and associated actions during a CAT II Approach for an ATR aircraft.


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4.1. ATR 72-500

AFCS and ADU

Flight intruments

A/C systems

Warnings

Actions at the time of failure detection > 800 ft AGL

Flap failure, jammed between 0 and 15 position

Revert to CAT I minima

Flap failure, jammed above 15 position

Continue Increase VAPP (flaps 30) by 10 kt

Engine failure


Hydraulic failure (without fluid loss)

Transfer No capability loss

First MFC module failure

Apply associated procedure continue the approach

Second MFC module failure

Apply associated procedure Revert to CAT I minima

Standby horizon flag


Radio altimeter warning on PNF EFIS


ATT/PIT/ROLL warning on any EFIS

Switch to valid AHRS Reengage AP Revert to CAT I minima

HDG warning on any EFIS

Switch to valid AHRS Revert to CAT I minima

< 800 ft AGL

< 500 ft AGL

Not applicable

First action before switching AHRS is to refer to standby horizon to determine the wrong AHRS Discontinue the approach


Loss of one CRT

Switch affected CRT OFF

Loss of both CRT on one side

Switch to valid SGU. Revert to CAT I minima

Loss of CM2 airspeed indicator and CM1 side if PF


Loss of any altimeter


AP disengage

Try to recover If impossible revert to CAT I FD approach

Discontinue the approach

Not applicable


Loss of ADU

Perform a CAT I minima manual approach

Loss of CAT II capability (Triple click)

Try to recover If impossible revert to CAT I minima

Multiply landing distance flaps 30 by 1.13


LOC / GS / ILS / warning on any EFIS

LOC or G/S excess deviation

Complementary actions


Table C1: Failures & associated actions during a CAT II approach.

4.2. ATR -600 For later revision.


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5. Maintenance Operational regulations request that on board guidance systems and equipment used for Low Visibility Operations be maintained in accordance with a maintenance program established by the operator in liaison with the aircraft manufacturer, and approved by the authority. On all ATR aircraft, equipment used for Low Visibility Operations is part of the basic design standard. Therefore, related tasks are covered by the ATR Maintenance Program. There is no special recommendation for scheduled maintenance tasks or functional checks to maintain CAT II / CAT III capabilities. In case of failure affecting the aircraft CAT II or CAT III capability, the aircraft status is primarily governed by status messages issued from a Multi Purpose Computer. However, crew entry in the Technical Log Book must take precedence. A log entry must be made each time the CAT II or CAT III capacity is not available. Concerning the auto-land capability on ATR 42-600 / 72-600 a program for unscheduled maintenance is established to advise on all necessary corrective actions / procedures following an automatic landing failure and/or component failure. A reliability programme is also established to monitor the system operational status.


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D. Airfield requirements

D - Airfield requirements 7B$75B$:2FKDSWHU$WR*PD\LQGG

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1. Aerodrome approval Operations with limited visual references at an aerodrome will need additional facilities, services and procedures to those required for good weather operations. It is the responsibility of the airport national Authority to verify that ground facilities and services meet ICAO specifications, before promulgating a runway as available for Category II or III operations. An operator shall not use an aerodrome for CAT II or CAT III operations unless it is approved for such operations by the State in which the aerodrome is located. The relevant ICAO documents for the approval of an aerodrome for Low Visibility Operations are: – Annex 14 – aerodrome design and operations – Annex 10 - ILS – Doc 9365 – Manual of All Weather Operations There are national differences in methods for licensing aerodromes. Some States may promulgate specific national requirements but they should not be less restrictive than CAT II and CATIII ICAO standards. The additional criteria to satisfy before opening an aerodrome to all-weather operations concern mainly the following items: – adequacy of runways and taxiways, – visual and non-visual aids, – control of obstacles, – assessment of RVR, – air traffic service, including surface movement control. The demonstration of compliance with ICAO standards is a long and complex process, with a large number of directives to satisfy. This section sums up the ICAO specifications for CAT II/III airports.

2. Runway and taxiway characteristics 2.1. Runway length There is no specific requirement concerning runway length for an aerodrome to be CAT II or III approved. The runway length should be adequate to meet the operational requirements of the aeroplanes for which the runway is intended.

2.2. Runway width The runway width should normally be not less than 45m.

2.3. Runway slope In order to permit the use of the automatic landing system, disregarding normal standards, it is recommended that for the first and the last quarter of the length of the runway the longitudinal slope does not exceed 0.8%.

2.4. Runway-holding position The location of a runway-holding position is such that a holding aircraft or a vehicle does not infringe the obstacle free zone, approach surface, take-off climb surface or ILS critical/sensitive area nor interferes with radio aids. Without distinction of approach categories, ICAO recommends that the distance between the runway-holding position and the runway centreline should not be less than 90m (or 107.5m for a 60m width runway). Nevertheless, for many airports, CAT II and CAT III holding positions are located at a minimum distance of 150m from the runway centreline.


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3. Effects of pre-threshold terrain profile The topography of an approach terrain is important in all weather operations. A regular and preferably leveled prethreshold area ensures correct radio altimeter functioning. The operation of automatic landing systems is dependent, among other things, on the radio altimeter. The flare profile, the rate of descent at touchdown, and the distance of the touchdown point from the runway threshold can, therefore, be affected by the profile of the terrain immediately preceding the threshold. The terrain which is most critical lies in a 60 m area on either side of the runway centreline and extends before the threshold, to the distance of at least 300 m into the approach area. Within this area, ICAO recommends that slope changes be avoided or, when it is not possible, that the rate of change between two consecutive slopes should not exceed 2% per 30m. On some airfields where underlying terrain is irregular, radar reflectors are used to stabilise the radio altimeter signals in the area preceding the runway threshold. Regardless of the effect on the AFCS during the landing phase, an irregular terrain profile up to 1000 m out from the threshold may have an influence on the determination of a CAT II decision height. It may also affect the approach management. This is particularly so where the terrain under approach is markedly lower than the threshold. Then the time available for the head down to head up transition, and for the visual cues acquisition, may be significantly shortened. “Hundred above” “Hundred above”

“Decision” “Decision” 200ft RA

DH=110 ft 210 ft RA

DH=100ft

available time for decision making

shortened time for decision making

Figure D1: Effect of terrain profile on time available for decision making

4. Obstacles clearances requirements Obstacle clearance is a primary safety consideration in the development of instrument flight procedures. The criteria and methods used aim to avoid any aircraft at take-off, on approach, landing or go-around touching obstacles on the ground. For each runway a series of Obstacle Limitation Surfaces (OLS) define the limits to which objects may project into the airspace. Those surfaces, established in accordance with ICAO Annex 14 Chapter 4, Obstacle restriction and removal, identify the lower limits of the aerodrome airspace above which objects become obstacles. Transitional Conical

Inner horizontal

Outer horizontal

Figure D2: Obstacle Limitation Surfaces (OLS)


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Inner approach surface

Inner transitional surface - slope 33.3% Runway

Threshold

18 m

60 m

900 m

Slope 33.3%

m

Slope=2%

H= 45 m

12 0


For precision approach, surfaces closer to the runway (i.e. inner approach, inner transitional and balked landing surface) define a volume of airspace in the immediate vicinity of the runway known as the Obstacle Free Zone (OFZ). This zone must be kept free from any fixed obstacle other than a low-mass and frangibly mounted equipments required for air navigation purposes.

Balked landing surface

Divergence 10%

1,800m or runway length L if L<1,800m

Figure D3: Obstacle Free Zone (OFZ)

In addition to the OFZ constraints, for each approach type an Obstacle Clearance Height (OCH) is calculated. For an aircraft on the approach track, the OCA/H ensures clearance of obstacles from the start of the final approach to the end of the intermediate missed approach segment. The OCH of a precision approach is defined as the lowest height at which a missed approach must be initiated to ensure compliance with the appropriate obstacle clearance design criteria. The OCH is referenced to the elevation of the relevant runway threshold and it is used to establish the approach operating minima (please refer to Paragraph G.1, Establishing operating minima). The ICAO Doc 8168 (PANS OPS) Volume II Part II Section 1 chapter 1, Instrument Landing System (ILS), presents different methods for the OCH calculation. Q Among

those methods, two of them involve a set of surfaces (basic ILS surfaces or Obstacle Assessment Surfaces (OAS)). The OCH is determined by accounting for all obstacles which penetrate those surfaces. OAS are established taking into account, amongst others, the glide path angle, the miss approach climb gradient, the localizer-threshold distance, the category of the approach, the use or not of autopilots certified for CAT II operation.

Q Another

method uses a Collision Risk Model (CRM). This method is employed mainly when the obstacle density below OAS is considered to be excessive. The CRM is a computer program that takes into account all obstacles located in the vicinity of the runway. It determines the minimum OCH which provides a safety target of 10–7 (1 in 10 million) per approach for risk of collision with obstacles.

Z Y

Glid

X

e pa

th

W

E

l

Fina

oach appr

se

cour

C

D La

nd

ing

th

re sh

old

Figure D4: ILS Obstacle Assessment Surfaces (OAS)

OCH is established for all Category I and Category II precision approaches and for each aircraft category (A,B,C,D). An OCH is not associated with CAT III operations. These are supported by overlapping protection from the CAT II criteria. Category III operations are possible only if the CAT II OCH is equal or less than 100ft.


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5. Navaids - Characteristics and limitations 5.1. General The precision instrument approach systems intended to support CAT II and CAT III operations are: – Instrument Landing System (ILS) – Microwave Landing System (MLS) – GNSS Landing System (GLS) The ILS has been the mainstay of landing system aids for well over 50 years. Although ILS has some limitation, for the time being it is the only system to support CAT II and CAT III operations on a world scale. The MLS has a number of operational advantages, including a wide selection of channels, an ability to allow curved approaches, a lesser sensibility to interference, an excellent performance in all weather, and a small “footprint” at the airports. Although some MLS systems became operational in the 1990s, airline reluctance to invest in MLS and the rise of GLS has jeopardised a widespread deployment. GLS (LAAS) is a landing systems based upon the Global Navigation Satellite System (GNSS Landing System). For Low Visibility Operations the landing system typically includes a Local Area differential Augmentation System (LAAS) located in the vicinity of the runway. The local area system uses differential techniques to correct and improve the accuracy of GPS, it may serve one or more runways, or nearby airports. GLS (LAAS) promises to provide CAT II and CAT III capability and is already included into FAA regulation. Nevertheless LAAS is currently a research and development project focusing on the resolution of integrity and safety issues: no approaches have been certified to date (Sept. 2009). It is worth noting that Wide Area Augmentation Systems (e.g., WAAS, EGNOS) are typically considered to be RNAV systems, and are not alone considered to be GLS able to support CAT II/III operations. For the time being ATR aircraft are not equipped with MLS or GLS; consequently only ILS is developed in this brochure.

5.2. ILS characteristics An ILS consists of three independent sub-systems: – the localizer providing lateral guidance. A Localizer antenna array is located beyond the departure end of the runway and consists of several pairs of directional antennas, – the glideslope, providing vertical guidance. A Glidepath (GP) antenna array is sited to one side of the runway touchdown zone, – marker beacons or DME providing information on the distance from the runway threshold. In modern ILS installations a DME, co-located usually with the Glideslope, augments or replaces marker beacons. Localizer and Glideslope signals are transmitted on different carrier frequencies but the technical principles are similar: For each system, two signals are transmitted: one is modulated at 90 Hz, the other at 150 Hz. The on board localizer and glideslope receivers measure the Difference in the Depth of Modulation (DDM) of the 90 Hz and 150 Hz signals The difference between the two signals varies depending on the position of the approaching aircraft from the centreline for the localizer and from the desired slope (approximately 3°) for the glideslope. If there is a predominance of either 90 Hz or 150 Hz modulation, the aircraft is off ILS axes. If the DDMs are zero, then the aircraft is on axes.


p. 41

LOC Aerial


90 Hz

Localizer

150 Hz

90 Hz

Glideslope

GS Aerial

150 Hz

50 ft

~1,000 ft

Figure D5: Localizer and glideslope signals emission patterns.

To achieve a high degree of integrity, monitors continually assess the vital characteristics of the transmissions. If any significant deviation beyond strict limits is detected, either the transmitters are automatically switched or the ILS is turned off.

Figure D6: Glideslope antenna

Figure D7: Localizer antenna array

5.3. ILS performances The ILS installation must conform to technical specifications contained in ICAO Annex 10, Volume 1. Ground and flight check are performed at regular intervals to detect any degradation in ILS performances. The aim of this brochure is not to describe in detail complex technical standards; nevertheless some figures give an idea of ILS performances:

Localizer At threshold a half dot-deviation on the ILS indicator means the plane is off course by 27m. At threshold the course alignment accuracy requested is: – for CAT II ILS: 7.5 meters (4.5m recommended) – alarm threshold: 7.5m – for CAT III ILS: 3 meters- alarm threshold: 6m


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Glideslope The beam width is 1.4° (0.7° for full scale deflection). At threshold a one dot-deviation equals about a 7-foot excursion from the prescribed glidepath, 14ft at 100ft.

Monitoring system For CAT II and CAT III ILS, the monitoring system is such that the period of radiation outside the performance limits never exceeds 2 seconds (recommended 1 second).

5.4. ILS classification ILS are classified according to their performances by using three characters as follows: Q I,

II, III: Performance category: – I: ILS performances sufficient to provide guidance down to 200ft – II: ILS performances sufficient to provide guidance down to 50ft – III: ILS performances sufficient to provide guidance down to and along the surface of the runway. Performances concern several parameters such as coverage, carrier modulation characteristics, course accuracy, alarm threshold… Q A,B,C,T,D

or E: This character defines the point to which the localizer course structure comply with the ICAO annex 10 technical standard. The position of these points is given on the figure here below

Q 1,2,3,4: this number indicates the level of integrity and continuity of service as defined by ICAO annex 10: Level 3 is a required objective for equipment supporting CAT II and CAT IIIA operation Level 4 basically relates to the needs of the full range of CAT III operations.

C

A

B

Stop end of runway T Threshold E

D 30ft

600m

900m

1050m 7.5km (4 Nm) Figure D8: ILS points

ILS Class vs. approach category – An ILS intended to support CAT II approaches would be described at least as a class II/T/3. – An ILS intended to support CAT III approaches would be typically described as a class III/E/4. – An ILS intended to support lower than Standard Category I operation must be certificated to: Class I/T/1 for operation to a minimum RVR of 450m RVR; or Class II/D/2 for operations to less than 450m RVR. Single ILS facilities are only acceptable if Level 2 performance is provided. – An ILS intended to support other than Standard Category II operation must be certificated to class II/D/2 for operations in less than 450m RVR or to a DH of less than 200ft.


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5.5. ILS protection ILS localizer and glideslope systems have some limitations. Localizer systems are sensitive to obstructions in the signal broadcast area. Glideslope systems are also limited by the terrain in front of the glideslope antennas. If terrain is sloping or uneven, reflections can create an uneven glidepath causing unwanted bar deflections. The areas within which movable objet may degrade the guidance signal must be defined and recognised. ICAO considers two kinds of protection areas: Q The

ILS critical areas are areas of defined dimensions about the localizer and glide path antennas. All vehicles and aircraft must remain outside these areas during all ILS operations. Critical areas are fenced and secured to prevent them from unauthorised access.

Q The

ILS sensitive areas are much wider. Their size depends on a number of factors including the type of ILS antenna, the topography, the ILS category and the size of aircraft operating on the airport. They have to be entered and exited during normal operation but, during low visibility procedures, clearance from ATC is required before entering sensitive areas. Their limits are marked on the taxiway by yellow lines, red stop bars and CAT II/III signs.

Designation of critical and sensitive areas is the airport authority responsibility. ATC control access to sensitive areas when low visibility procedures are in force (please refer to Paragraph D.7, ATC procedures). With the same aim of protecting the ILS beam, ATC usually increase separation between aircraft on landing or take-off. 300m or end of runway

Localizer sensitive area

Localizer critical area

Runway

120m Localizer antenna Figure D9: Typical localizer critical and sensitive areas

Runway threshold Glideslope antenna

250m Glideslope critical area

30m

Glideslope sensitive area

Taxiway

Figure D10: Typical glideslope critical and sensitive areas

6. Characteristics of the visual aids The runway marking and lighting standards are detailed in ICAO Annex 14 Chapter 5, Visual aids for navigation.

6.1. Runway markings There is a no specific CAT II or CAT III requirement concerning runway markings except for the runway centreline that must have a width not less than 0.9m. The touchdown zone markings are mandatory for all runways supporting precision approaches, but CAT II/III runways usually have a distance coding.


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CAT II and CAT III specific holding positions are normally located upstream of the standard holding position to avoid aircraft entering into the obstacle free zone or the ILS sensitive area. The markings used are also specific. They are associated with CAT II or CAT III signs placed on either edge of the taxiway. The sign CAT III must be accompanied with flashing lights.

Runway

Figure D10: CAT II /III holding position signs

2.1m

Taxiway

3m

Figure D11: CAT II /III holding position markings

Figure D13: Taxiway markings for CAT II / III operations

Figure D13: Touchdown zone markings for runway with a length of 2400m or more

6.2. CAT II/III Lighting systems Runway and approach lights on runways intended to support CAT II or CAT III operations consist of high intensity lights. The main characteristics of a lighting system meeting the ICAO Annex 14 standard for CAT II/III operations are explained in the following paragraph.


p. 45


6.2.1 Taxiway lights Taxiway lights Colours

Spacing

Special features

Centre line

green

15m on a straight section 7.5m on curves

Requested for operations with RVR <350m

Edge lights

blue

60m on a straight section <60m on curves

Not requested for taxiways with centre line lights Table D1: Taxiway lights

6.2.2. Stop bars Stop bars consists of red lights spaced at interval of 3m across the taxiway. In conditions with less than 350m RVR a stop bar shall be provided at every runway-holding position, except where appropriate aids and/or procedures (e.g. surface movement radar) are available to prevent inadvertent runway incursions. Stop bars are controlled by Air Traffic Services; the switching is made in conjunction with at least 3 taxiway centre line lights.

Figure D14: Stop bars

Figure D15: Stop bar closed

Figure D16: Stop bar opened

6.2.3. Runway guard lights Runway guard lights consist of two pairs of flashing yellow lights located at each side of the taxiway. Runway guard lights are provided at each taxiway / Runway intersection where a stop bar is not installed. Guard lights: pair of flashing yellow lights

Figure D17: Guard lights


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6.2.4. Runway lights Runway lights

Colours

Spacing

Special features

Threshold

Green – unidirectional

3m

Runway end

Red – unidirectional

6m

At least 6 lights

Edge

– Variable white – may be yellow from 600m to the runway end (limited to 1/3 of the runway)

60m

May be omitted at the intersection

Centre line

– variable white – alternate red and white from 900m (or runway mid point if RWY length <1800m) to 300m from the runway end – red from 300m to the runway end

15m – may be reduced to 7.5m

Touchdown zone

Barrette of variable white – unidirectional

– barrettes – longitudinal spacing : 60 or 30m – barrettes – lateral spacing: 18 to 22.5m

– A barrette is composed of at least 3 lights. Its length is between 3 and 4.5m – TDZ extends from threshold to 900m from threshold (or to runway mid point if RWY length <1800m) Table D2: Runway lights

6.2.5. The approach lighting system The approach lighting system consists of a row of lights on the extended centreline of the runway, extending, wherever possible, over a distance of 900m from the threshold. In addition, the system has two side rows of red lights, extending 270m from the threshold, and crossbars located at 150m, 300m, 450m, 600m and 750m from the threshold. Such approach lighting intends to support all low visibility approaches. Depending on the operational regulations, reduced lengths may be acceptable for CAT II or CAT III operations (please refer to Paragraph E.8, Effect of failure of ground equipments). For CAT I approaches a reduced approach lighting system causes an increase in operating minima. Approach lights

Colours

Spacing

Special features

Extended centre line for the first 300m from the threshold

Barrettes of variable white

30m

Minimum barrette length: 4m. Maximum spacing between barrettes’ lights: 1.5m

Extended centre line beyond 300m from the threshold

Variable white

30m

Consists of either: – barrettes, as used on the inner 300m – 2 lights in the central 300m and 3 lights in the outer 300m

Side row

red

– barrettes - longitudinal spacing : 30m – barrettes – lateral spacing: equal to that of the TDZ

Length of barrettes and spacing of its lights equal to those of the TDZ

Crossbar located at 150m from threshold

Variable white

Lights’ lateral spacing: ≤2.7m Fills the gap between the centre line and the side row barrettes

Crossbar located at 300m from threshold

Variable white

Lights’ lateral spacing: ≤2.7m Extends to 15m on both side of the center line Table D3: Approach lights


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Figure D18: CAT II/III approach light system


p. 48

Figure D19: Approach lights description

Figure D20: Approach lights during a night landing

6.2.6. Lighting system condition For a runway meant for use in low visibility conditions, the electrical systems for the power supply, lighting and control of the lighting are designed so that an equipment failure will not leave the pilot with inadequate visual guidance or misleading information. To achieve the required level of availability a secondary power supply must be able to switch over within one second (time extended to 15s for taxiway lights, edge lights and approach lights beyond 300m from the threshold). The maintenance services must ensure that, during any period of Category II or III operations, all approach and runway lights are serviceable, and that in any event at least 95% of the lights are serviceable except for runway end lights (75%), approach lights beyond 450m (85%) and TDZ lights (90%). In addition two adjacent lights should not remain unserviceable except for lights in a barrette or a crossbar.

6.3. Lighting systems for Lower than Standard CAT I and other than Standard CAT II approaches Lower than Standard CAT I and other than Standard CAT II approaches can be conducted on a runway where some or all of the elements of the ICAO Annex 14 Precision Approach Category II lighting systems are not available. For those approaches the lighting system must include at least the runway lighting (runway edge lights, threshold lights, runway end lights). As for CAT I operations, the length, the configuration and the intensity of the approach lighting has a direct impact on the minimum value of the RVR requested to perform such approaches (Please refer to Paragraph G.1, Establishing operating minima). In order to easily associate an RVR to a particular approach lighting system the European regulation has classified approach lighting into four main categories: Q FALS

(full approach light system): ICAO: Precision approach CAT I Lighting System (HIALS 720 m ≥) distance coded centreline, Barrette centreline.

Q IALS

(intermediate approach light system): ICAO: Simple approach lighting system (HIALS 420-719 m) single source, barrette.

Q BALS

(basic approach light system): Any other approach lighting System (HIALS, MIALS or ALS 210-419 m)

Q NALS

(no approach light system): Any other approach lighting system (HIALS, MIALS or ALS < 210 m) or no approach lights


p. 49


Presence of touch-down zone lights and/or runway centre line lights has also an impact on minima (Please refer to Paragraph G.1, Establishing operating minima).

Figure D21: Basic Approach Light System (BALS)

Figure D22: Full Approach Light System (FALS)

7. ATC Procedures In low visibility conditions the increased operating risk due to the lack of visual control requires that the aerodrome operator or Air traffic service provide specific Low Visibility Procedures (LVP). Those procedures are aimed at maintaining a safe ground environment for aircraft and vehicles by reducing to a minimum level the risk of collision and infringement of an active runway. Each aerodrome authority develops its own procedures taking into account local conditions; however, the main issues to address are: – – – – – – – –

control of any person or vehicle entering on the manoeuvering area, protection of the OFZ by the control of ground movements, protection of the ILS critical area and the ILS sensitive area by control of ground movements, separations between successive landing aeroplanes and between a departing aeroplane overflying the ILS antennas and the arriving aeroplane, control of runway access to prevent runway incursion by using, if necessary, any additional ground aids and equipment, information of the pilots in case off degradation in ILS performances and/or visual aids, establishment of appropriate emergency procedures (deployment of rescue and fire fighting services), reduction of the aerodrome capacity during Low Visibility Operations.

The ATS or airport authority has to define the weather conditions at which low visibility procedures come into operation. The delay to set up those procedures requires anticipating on weather downgrading: usually LVP are activated before reaching the CAT II conditions (e.g. when RVR is lower than 600m or ceiling equal or lower than 200ft). An operator shall verify that Low Visibility Procedures (LVP) have been established, and will be enforced, at aerodromes where Low Visibility Operations are to be conducted. Before commencing a Low Visibility Take-Off, a lower than Standard CAT I, an other than Standard CAT II, or a Category II or III approach, the commander must ensure that appropriate Low Visibility Procedures are in operation. There are a number of aerodromes which may support Low Visibility Take-Off although they are not approved for Category II or III operations. In such case, low visibility procedures may be lightened. The simplest acceptable LVP may consist in allowing only one aircraft at a time on the manoeuvering area and in restricting vehicle traffic to the absolute minimum.


p. 50

E. Flight crew operating procedures

E - Flight crew operating procedures 7B$75B$:2FKDSWHU$WR*PD\LQGG

p. 51


1. General Operators must develop procedures and operational instructions to be used by flight crews. These procedures and instructions must be published in the Operations Manual. All the instructions must be compatible with the limitations and mandatory procedures contained in the approved Aircraft Flight Manual. The procedures and the operational instructions should cover normal and abnormal situations that can be encountered in actual operations. Each airline develops its own procedures taking into account its own specificities. The following chapters give guidance material on the main items to be covered. Proposed procedures need to be modified or adapted to the airline operating rules according to the operational regulation in force.

General principles Q CAT

II, other than Standard CAT II and CAT III approaches on ATR are ILS approaches for which decision height (DH) is determined by means of a radio altimeter.

Q All

CAT Il, CAT III, other than Standard CAT II and lower than Standard CAT I approaches are performed with the autopilot engaged. – For CAT II approaches, the autopilot is disconnected at a height of 80ft and the landing is performed manually. – For CAT IIIA, other than Standard CAT II and lower than Standard CAT I approaches the autopilot is disconnected at touchdown: The approach and landing are performed automatically, the aircraft is controlled manually during the roll-out.

Q Prior

to conducting a Low Visibility Take-Off, CAT Il approach, CAT III approach, other than Standard CAT II or lower than Standard CAT I approach, each crew member must be qualified for such operations and have completed an approved training and checking program (please refer to chapter F, Flight crew training and qualification).

Q CAT

Il, CAT III, other than Standard CAT II and lower than Standard CAT I approaches are conducted according to a clearly defined task sharing. Basically the pilot flying is the one who acquires the visual references and takes the decision to land or to carry out a go-around at DH. The Pilot Not Flying has the task of monitoring the approach with permanent reference to the instruments and to make the appropriate call-outs.

2. Pre-flight procedures In addition to normal flight preparation, the following planning and preparation must be performed when CAT Il, CAT III, other than Standard CAT II and lower than Standard CAT I approaches are planned. Q Aircraft

status check: review the log book to confirm that no write-up during previous flights affects equipment required for Low Visibility Operations. The required equipment list is given in the FCOM and in the AFM and is duplicated in the operating manual (please refer to Paragraph C.3, Aircraft minimum equipment required). The dispatch conditions of the MEL should be in accordance with this list.

Q Crew

qualification: check that both Captain and First Officer are qualified and current to perform Low Visibility Operations.

Q Weather

information: In case of low visibility conditions at take-off or at the destination aerodrome, check that the weather forecasts at the take-off alternate aerodrome and/or at the destination alternate aerodromes allow complying with the operating regulation on planning minima.

Q NOTAMs

review: make sure that at the destination visual aids (runway and approach lighting) and non-visual aids (ILS, RVR equipment, stand-by power) still meet LVO requirements.

Q Fuel

planning: assess the need to take extra fuel for possible approach delays.


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3. On ground procedures and precautions 3.1. General Ground movement starts from the parking stand to the take-off run, and from the end of the landing roll to the parking stand. Many crew members are not aware that taxiing is one of the most critical phases in low visibility conditions. Aerodrome complexity and traffic density contributes to increase the risk of: – Mistake in location and identification of taxi routes to be followed, – Collision with vehicles or other aircraft on the maneuver area, at taxiway intersections or along taxiways, – Unauthorised entry to an active runway. The most hazardous situation comes from an unauthorized entry on to an operational runway. In restricted visibility or at night this can happen without the ATC controller being immediately aware of the situation. On airports approved to support Low Visibility Operations, active runways are clearly and unmistakably marked. The most common cause of unauthorised runway incursion is a misunderstood clearance. The crew believes that it has been cleared to enter or cross a runway and proceeds unless there is some obvious, immediate, danger. Language difficulties, busy environment, confusing phraseology, congested radio frequencies, cockpit distractions, time pressure, and similarity of call signs are all factors which may result in a misinterpretation of what has been said. Conversely, a good understanding of the over-all situation (gained by monitoring the ground frequency), a systematic request of clearance confirmation at the slightest doubt, a confirmation of clearance to enter a runway by visual signals (e.g. stop bars if installed) are good means to reduce the risks associated to a misunderstood clearance.

3.2. Recommended procedures The following procedures could give support in conducting safe and efficient taxi operations

3.2.1. Prior to taxiing Q Prepare

and read low visibility taxi charts (when published),

Q Determine

the expected taxi route to be followed,

Q Perform

a briefing with a detailed description of the routing between the apron and the holding point by using the airport chart and/or the low visibility taxi charts (when published); ensure that both crewmembers understand the expected taxi route,

Q Identify

the main intersections, the direction changes, the holding positions and the areas to be avoided,

Q Write

down the taxi clearance when received (CM2 copies it on the Nav Log or through the scratch pad which can be easily use as a short notepad),

Q Amend Q Adjust

the taxi briefing in accordance with the taxi clearance before commencing taxi,

the pilot’s seat and rudder pedals so that it is possible to apply maximum braking with full pedals deflec-

tion, Q Start

engine 1 before taxiing,

Q On

ATR -600 select the airport moving map on both MFD,

Q On

ATR equipped with an Electronic Flight Bag, activate the airport moving map.

3.2.2. During taxi Q In

low visibility conditions taxi with more caution, and at slower speeds,

Q Both

crew members must be concentrated on the visual surveillance and on the identification of taxi routes to be followed. Consequently: – Both CM1 and CM2 must have their taxi charts visible, – The flight crew should postpone all unnecessary activity and duties,


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– Taxi actions and checklist, before take-off briefing and company communication are performed preferably when the aircraft is stopped, – CM2 should follow taxi progress on the airport diagram, check consistency of taxiway orientation with aircraft heading, call out all signs to verify position. – On ATR -600 CM1 and CM2 control aircraft position on the airport moving map (please refer to Paragraph E.4, Low Visibility Take-Off). Q Always

use taxi light to visually indicate movement. (When entering any active runway ensure all exterior lights are illuminated).

Q Read

back all clearances: If any crewmember is in doubt regarding the clearance, stop the airplane and verify taxi routing against the written clearance or with ATC.

Q In

case of malfunction or if a problem occurs during taxi, stop the aircraft, set parking brake, and inform ATC before performing any action.

Q If

and when the crew feels lost or has any doubt on their position, they must ask ATC for help.

3.2.3. Prior to approach phase Q When

low visibility conditions exist at destination, the approach briefing should include a detailed description of the routing from the runway exit to the apron area. Potential difficulties should be addressed in reference to the airport chart and/or low visibility taxi charts (when published).

Q As

crew members establish contact with the company staff at destination, they request the assigned stand number to confirm (or eventually amend) the briefing.

Q If

it is necessary to cross a parallel runway after landing, the standard procedure is to hold short between runways. The crew members must monitor the tower frequency and be sure to have received a clearance to cross the runway before proceeding.

3.3. Usual difficulties Changes in visibility or light intensity, the disappearance of familiar landmarks, the use of a rarely employed taxiway or runway, an excessive concentration on the taxiway centreline can all contribute to mistakes in location identification and positioning.

Figure E1: Low Visibility taxiing

Pilots can get confused at intersections if they do not see the signs indicating which taxiway they are crossing. The problem lies in the fact that the signs are placed a fair distance before the intersection - an important feature which allows the crew to anticipate -, and that they are not repeated as a confirmation of the intersection. In fact, at a given intersection, the only visible signs may be those for the next intersection. For a variety of reasons pilots may face a change of route during the taxi phase: taxiing to the gate is most difficult when the route is changed in mid-stream. Once pilots get a mental picture of the route they need to take from the runway to the gate, it is hard to replace it with another route. Such situation requires increased vigilance during taxi routing and whilst in visual surveillance


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3.4. Airport moving map 3.4.1. Electronic Flight Bag (EFB) The PilotView® EFB can be fitted on any ATR version. EFB Chart viewer applications are provided by Jepessen, Lido or EAG. These interactive viewers allow the display of the aircraft position on the airport charts, from the aircraft GPS position input. During taxi, this is particularly interesting for pilots maneuvering around unfamiliar airports. This efficiently increases situational awareness and reduces runway incursions.

3.4.2. ATR -600 The airport NAV provides the flight crew with aircraft progression on airport surface by displaying an aircraft symbol on the airport map. Nevertheless the other aircraft are not displayed on the map. Such device is of real assistance to the pilots: it increases efficiency and safety during low-visibility surface operations.

Figure E2: Airport moving map

4. Low visibility take-off (LVTO) 4.1. General Low visibility take-offs on ATR are performed with the exclusive use of visual references during the take-off run and eventually during the aborted take-off phase. Consequently for LVTO on ATR: – there is no specific requirement concerning airborne equipment, – the standard take-off operating procedure applies. The airport installation (runway lighting system, RVR measurement system ...) is the determining factor in establishing the minimum acceptable values of RVR allowing a take-off based exclusively on visual reference. These minimum RVR values, defined as take-off minima, vary according to the applicable operational regulation. As an example, the following Paragraph E.4.2 presents the rules applicable for operators subject to European regulation. In addition to the conditions prescribed by regulation for LVTO, the operator may edit specific instructions such as: – The Captain is the Pilot flying – Rolling take-offs are prohibited – When possible, the full length of the runway is used…. In low visibility conditions it is usually not possible to come back and land at the aerodrome of departure. Consequently, a suitable take-off alternate aerodrome has to be selected, according to the applicable operational regulation.


p. 55


4.2. Low Visibility Take-Off under European regulation (EU-OPS) Operators must verify that Low Visibility Procedures (LVPs) have been established and will be enforced at aerodromes where Low Visibility Take-Offs are to be encountered. Conversion of reported meteorological visibility into RVR (please refer to Paragraph B.3.5, Conversion of reported meteorological visibility to RVR) is not permitted at take-off.

Take-offs with RVR less than 400m are considered by EU-OPS as LVTO and are split into two categories:

LVTO with RVR between 400m and 150m No operational approval is required to perform LVTO with these minima. The minimum RVR depends on the runway lighting and markings and on the RVR measurement system, in accordance with the table below: Ground facilities

RVR/ visibility(1)

Nil (day only)

RVR/visibility ≥500m

Runway edge lighting and/or centreline marking (for night operation, edge and runway end lights are required)

500m> RVR/visibility ≥250m

Runway edge and centreline lighting

250m> RVR/visibility ≥200m

Runway edge and centreline lighting and multiple RVR information

200m> RVR/visibility ≥150m(2)

(1)

The reported RVR/Visibility value representative of the initial part of the take-off run can be replaced by pilot assessment. (2)

RVR must be achieved for all of the relevant RVR reporting point (covering the acceleration/stop distance) except for the initial part of the take-off run that can be replaced by pilot assessment.

LVTO with RVR lower than 150m but not lower than 125m Take-offs in this range of RVR are subject to an operational approval by the Authority. Both flight crew members must be qualified for such operations and have completed training in a flight simulator (please refer to Chapter F, Flight crew training and qualification). The following conditions must also be met: – High intensity runway centreline lights spaced 15m or less and high intensity edge lights spaced 60m or less are in operation, – A 90m visual segment is available from the cockpit at the start of the take-off run, – The 125m RVR value has been achieved for all of the relevant RVR reporting points (no exemption for the initial part of the take off run). NOTE: The obscured segment for an ATR aircraft on ground is only 8 meters. Consequently, with 125m RVR, the condition on a 90m visual segment should not be a limiting condition. Example: EU OPS Take-off minima published for Toulouse Airport RVR <400m: low visibility take off. LVP must be in force.

Conditions on ground facilities and Associated RVR For CAT B (ATR)

Minimum RVR of 125m for Approved Operators


p. 56

Summary of flight crew actions before commencing a Low Visibility Take-Off under European regulation Q check

that low visibility procedures are active,

Q check

that the reported Visibility/RVR is not below the published minima (or the operator minima, if higher) according to the lighting and markings available,

Q check

that a take-off alternate aerodrome is available: as ATR aircraft are not certified to perform CAT II or CAT III approaches with one engine out, when the reported RVR is below the minimum value required for a Category I approach on the departure aerodrome (basically 550m), a take-off alternate aerodrome with weather conditions above the landing minima must be selected (please refer to EU-OPS 1.297, Planning minima for IFR flights),

Q for

take-off with RVR=125m check that the additional conditions are satisfied (Operator approval, crew qualification, runway lights spacing, visual segment, RVR for all relevant reporting points),

Q apply

standard take-off procedures and task sharing, except if airline policy introduces specific requests.

5. Approach preparation The following actions have to be performed preferably before the start of descent and in any case before the beginning of the approach phase.

5.1. Conditions at destination / at the alternate aerodrome When low visibility conditions are expected at destination, the flight crew should take ATIS as soon as possible. A weather analysis allows the crew to determine if present conditions require a low visibility approach and if the wind is compatible with the CAT II/III wind limitation (please refer to Paragraphs B.2.2, The effect of wind and turbulences and C.1.4, AFM content). The weather at the selected alternate aerodrome should also be collected. It must be checked that weather conditions at the destination or at the alternate aerodrome will be, at the expected time of arrival, above the operating minima. If weather conditions at destination are below the operating minima, the flight can be continued towards the destination (but not beyond the approach ban point) as long as conditions at the alternate are above the landing minima. If a CAT Il, CAT III, other than Standard CAT II or lower than Standard CAT I approach is likely, it must be check that LVPs are reported active. If any ground equipment is reported unserviceable, the effect on the minima must be determined (please refer to Paragraph E.8, Effects of failure of ground equipments).

5.2. Aircraft capability Flight crew members must verify the technical status of the aircraft to ensure that it has the capability to perform a low visibility approach. They must consider any equipment out of order, including that which failed during the flight. It must be checked, by using the lists published in the AFM and in the operating manual (please refer to Paragraph C.3, Aircraft minimum equipment required), that the minimum equipment required to perform CAT Il, CAT III, other than Standard CAT II or lower than Standard CAT I approach is available.

5.3. Fuel calculation When low visibility procedures are in force on an airfield, spacing between aircraft is increased and the number of runways in use may be reduced. The airport may have been closed for a time with several aircraft already waiting for weather improvement. If weather conditions are fluctuating, some aircraft going around may attempt another approach. For all these reasons, low visibility conditions often generate holding time for arriving aircraft. Consequently


p. 57


it is necessary to perform an accurate fuel management to establish the maximum holding time at destination before diverting. The crew should also consider the risk of holding due to a large number of diverting flights at the alternate aerodrome.

5.4. DH setting In addition to the standard setting performed prior to any ILS approach (speeds bugs, TQ bugs, Markers volume), for a CAT II, other than Standard CAT II or CATIII approach, the DH of the procedure must be set and cross-checked. A radio altimeter test is recommended.

Figure E3: DH setting on EADI

5.5. Approach briefing The approach briefing should include normal items, as for any IFR arrival, and in addition, the following subjects should be covered prior to a low visibility approach: Q qualification

of each flight crew member,

Q aircraft

systems status and capacity,

Q airfield

and runway operational status CAT II / CAT III, LVP in force…,

Q weather Q holding

conditions at destination, compatibility with the applicable minima,

time available before diverting,

Q brief

review of task sharing and call-outs,

Q brief

review of procedure in case of malfunction above and below 800ft,

Q review

of routing from the runway exit to the apron area,

Q review

of the go-around procedure,

Q alternate

aerodrome selected and weather conditions.

5.6. Cabin crew information A low visibility approach requires a specific task sharing between flight crew members. Both must be concentrated on systems monitoring and on the actions and call-out sequencing. In order to maintain a sterile cockpit during such approaches, the cabin crew must be informed that a low visibility approach will be performed. They are invited to not disturb the flight crew and to avoid awkward calls, except in case of emergency.


p. 58

5.7. Seat position Each flight crew member has to adjust his seat height and position to obtain an optimum visual segment. The seat is correctly adjusted when the pilot’s eyes are in line with the red and white balls located above the glare shield.

Figure E4: Seat position setting

6. Normal procedures for low visibility approaches 6.1. General CAT II approaches are conducted in automatic mode down to 80ft RA, the autopilot is disconnected at 80ft and landing and roll out are performed manually. CAT III, other than Standard CAT II and lower than Standard CAT I approaches are conducted in automatic mode, with the speed hold function engaged all the way to touchdown. The roll-out is performed manually. The go-around is performed manually using the flight director guidance. The DH recognition is made in reference to the height measured by radio-altimeter and all height call-outs are based on the radio altimeter. The approach may be continued below DH provided that the required visual reference is established at the DH. Flight crew members’ duties during approach, flare, roll-out and missed approach are to be clearly delineated in the Operations Manual. Special attention should be paid to the allocation of flight crew duties so as to ensure that the workload of the pilot making the decision to land or to execute a missed approach enables the pilot to concentrate on supervision and on the decision-making process. The task sharing proposed in Paragraph E.6.3 here below is one example of how to conduct a low visibility approach. It can be adapted by operators to be consistent with their own standard procedures; nevertheless, the AFM procedures must always be observed.

6.2. Approach ban / RVR controlling Policy regarding approach ban and RVR controlling may slightly differ according to the operational regulation applied. EU rules for approach ban and RVR controlling (cf. EU OPS 1.405): Q The

approach shall not be continued beyond the OM or equivalent position or 1000ft above the aerodrome (where no OM or equivalent position exists) if the reported RVR is less than the applicable minima.

Q After

passing this position, if the RVR falls below the applicable minima, the approach may be continued to DH.

The touchdown zone RVR is always controlled. If reported and relevant, the mid-point and the stop-end point are also controlled: the minimum RVR value for mid-point is 125m and 75m for the stop-end point. Relevant means: part of the runway used during the high speed phase of the landing down to a speed of approximately 60kts.This has to be appreciated taking into account the conditions of the day. Nevertheless, most of the time, given the ATRs’ landing distance (usually short), only TDZ RVR needs to be controlled.


p. 59


In summary, when passing OM or equivalent position if the last transmitted RVR for touch down zone is below the operating minima, a go-around is initiated.

6.3. Task sharing ATR AFM and FCOM procedures for low visibility approaches indicate task sharing between PF and PNF without specifying the real position of PF. This was intentionally done to give airlines the possibility of adapting their own policy. At the ATR Training Centres the recommended task sharing for low visibility approach is that CM1 is PF and CM2 is PNF. The workload is distributed in such a way that PF primary tasks are supervising and decision making, and the PNF primary task is the monitoring of automatic systems. In summary tasks are enacted and shared as follows:

CM1 - PF Q is

head down during approach,

Q monitors Q controls Q has

A/C position, flight path parameters and AP,

the speed,

hands on controls and power levers throughout the approach,

Q selects

modes and announces changes,

Q requests

checklists, flaps setting and gear extension,

Q is

head up approaching DH to search visual references,

Q at

DH, announces the decision to land or to go around,

Q in

CAT II: takes manual control at 80 ft and performs a manual landing,

Q in

CAT III, monitors flare and de-crab, at touchdown disconnects auto pilot, retards power levers and takes manual control for the roll-out.

CM2 - PNF Q is

head down to monitor flight instruments throughout approach, go-around or landing until rollout completion,

Q takes

charge of radio communications,

Q carries Q calls

out actions requested by CM1 (flaps setting, gear extension, AFCS (or FGCS) selection),

any deviation or failure warning,

Q monitors

auto call-out or calls out radio heights including “100 above”,

Q at

DH, if decision is not announced by CM1, calls out “DECISION”- If no response from CM1, initiates a goaround.

6.4. Normal procedures on classic instruments ATR for CAT II approaches The Table here below presents the detailed task-sharing recommended by ATR Training Centres for CAT II approaches with ATR-500 series, but it can be extended to other classic instruments ATR.


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E: Execute

A: Announce

C: Check

FLIGHT EVENTS / ACTIONS

O: Order

Items specific to CAT II CM1 (PF) ANNOUNCEMENTS CM2 (PNF) ANNOUNCEMENTS REMARKS

CM1

CM2

E E PF

E PNF

E/A E/A E

C C E

“ILS NAV 1set” - adjust Marker volume “NAV 2 VOR set”

E /A

C

O/E A O C O O

E/A A E C E A E/C E

“Approach mode set” “LOC white, G/S white” “VOR alive” “LOC star” “Runway Axis confirm” “Set RWY HDG, Dual ILS” “Rwy HDG set, Dual ILS set” “CAT II Capability” “STBY horizon checked” “Glide slope alive” “Flaps fifteen” “Speed checked” - set flaps to 15° “Flaps fifteen” “Speed bug white bug plus 10” “one dot” “Gear down” “Speed checked” - set LDG lever down, PWR MGT to TO, Taxi light ON “LDG gear down” “Half dot” “Flaps 30” “Speed checked” - set flaps to 30° “Flaps 30” “Speed bug V approach” “G/S star” “Set go-around altitude” “XXX ft set” “Before Landing C/L” “Center HDG bug”

Outer marker or equivalent position but not lower than 1000ft Check the altitude on radio altimeter and altimeter Check that A/C is stabilized

C

C/A

“Outer, altitude checked, stabilized” (1)

A

C

800ft RA Check dual coupling and no stars on LOC or G/S 500ft RA Speed maintain to Vapp +10kts/-5kts DH +100RA CM1 head up CM2 Head down DH (RA)

C

C/A

“Eight hundred, Dual coupling, No star” CM2 starts monitor ILS deviation

C E C

A C (A) A

“500”

Before descent CAT II briefing RA test / DH setting Not later than IAF Before Localizer interception NAV 1 ILS NAV 2 VOR (or ILS) ILS/VOR identification Cleared for approach App mode selected VOR alive LOC star Check HDG/Course/QFU HDG bug on RWY HDG / NAV 2 ILS CAT II on ADU Check STBY Horizon G/S alive Flaps to 15°

A O A E/A

C A

O

Flaps 15 O/E G/S one dot Gear to down

A C E/A E/A

E/A A E A

O E/A

Three Green lights G/S ½ dot Flaps to 30°

A A O

Flaps 30 G/S star Set Go-around altitude Before landing C/L Heading bug centered

A

“We continue”

“Hundred above” CM1 look outside for visual references “Decision”


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If visual references sufficient E: Execute

A: Announce

C: Check

O: Order

FLIGHT EVENTS / ACTIONS Approach is continued 80ft RA AP disconnection 50ft RA 20ft RA

CM1

Items specific to CAT II CM2

A

CM1 (PF) ANNOUNCEMENTS CM2 (PNF) ANNOUNCEMENTS REMARKS “Landing”

C E/A

A C

“80” “AP off” CM1 disconnects AP at 80 ft(2)

C C

A A

“50” “20” CM1 reduces PL and performs a manual landing CM2 remains head down until aircraft is on the ground with IAS< 70kts

A A

“Two low pitch” “70 kts” “I have control”

A

“Runway vacated” message to ATC

Low pitch 70kts A Runway vacated (1)

Stabilised means: – On the final approach segment flight path – In landing configuration at Vapp speed – Final checklist completed (2) On aircraft fitted with MOD 0069, AP can be disconnected between 80ft and 50ft (50ft is the minimum height certified for use of autopilot in approach mode)

If no visual or loss of visual reference or wrong positioning FLIGHT EVENTS / ACTIONS Approach is discontinued Normal Go-around procedure

CM1

CM2

A /E E

CM1 ANNOUNCEMENT CM2 ANNOUNCEMENTS REMARKS “Go-around – set power - Flaps one notch”

E

CAT 2 message on ADU The CAT2 message must be displayed before proceeding to Category II approach minima. This message remains displayed for the duration of the approach if all the CAT II conditions remain satisfied. If those conditions are lost the CAT2 INVALID message flashes on ADU. (Please refer to Paragraph C.2.1, AFCS on classic- instruments ATR)

Figure E5: CAT 2 display on ADU


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Dual couple approach mode Dual coupling is confirmed by checking that both the CPL arrows are displayed on the AFCS control panel. (Please refer to Paragraph C.2.1, AFCS on classic instruments ATR, for dual coupling conditions)

Figure E6: CPL on AFCS control panel

Key points for a CAT II approach – IAF: if the pilot flying on the flight leg is CM2, then CM1 should become PF not farther than IAF. – OM or equivalent position but not lower than 1000ft: it is the approach ban point. This point is also used to confirm glide slope and to check stabilisation. – 800ft RA: LOC and GS must be fully captured (no *) and dual coupling confirmed – this point is also a key point in failure management logic: below 800ft RA any failure should conduct to a go-around (Please refer to Paragraph E.7, Abnormal procedures). – DH +100ft: CM1 moves head up and searches visual references. – DH: CM1 decides to land or to go around. – 80ft: CM1 disconnects AP.

NAV 2 VOR set

CALL-OUTS DURING A CATEGORY II APPROACH

ILS NAV 1 set Approach mode set LOC white, GS white

GS star Set go around altitude

Speed bug white bug +10

CM1 (PF) call-outs

STBY horizon checked

Speed bug V approach

CM2 (PNF) call-outs

Gear down

Before LDG C/L

Flaps 30

LOC star CAT II capability

Flaps 15

Center HDG bug

Go around set-power flaps one notch

Half dot

xxxft set We continue

Speed checked Flaps 30 Outer, Altitude checked, Stabilized

500 Landing 80

AP off

50 20

100 above Decision 100ft RA

800ft RA

One dot Speed checked Flaps 15

VOR alive

Set RWY HDG, dual ILS

RWY HDG set, Dual ILS set

RWY axis confirm

LDG gear down Glide slope alive

Eight hundred, Dual coupling, No star

Two low pitch


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6.5. Normal procedures and task sharing for CAT III, other than Standard CAT II and lower than Standard CAT I approaches on ATR -600 For later revision.

6.6.Visual segment at DH and minimum visual references The minimum visual references allowing at the decision height to continue the approach and landing must be clearly defined in the Operations Manual and be in accordance with the applicable operational regulation.

Figure E7: Visual segment approaching CAT II minima

Figure E8: Visual segment at 80 ft

In CAT II conditions, the visual cues must be sufficient to enable the pilots to judge the aircraft’s orientation to the runway and to perform a manual landing. In CAT III, visual cues must allow the pilot to decide if the aircraft will land in the touch down zone. In order to establish lateral position and cross track velocity most pilots need not less than a 3 lights segment of the centreline of the approach light, or runway centre line or runway edge lines. For roll guidance, most pilots need to see a lateral element of the ground pattern (e.g an approach lighting cross bar, the landing threshold, or a barrette of the TDZ). To make an accurate adjustment to the flight path in the vertical plane, such as a flare, most pilots need to see a point on the ground which has a low or a zero rate of apparent movement relative to the aircraft. On the basis of those findings, the European regulation states that a pilot may not continue an approach below DH unless visual references in accordance with the table hereunder are obtained and maintained. Use of landing lights at night in low visibility conditions can be detrimental to the acquisition of visual references. Reflected lights from water droplets or snow may actually reduce visibility. Landing lights would therefore not normally be used in Category II/III weather conditions.


p. 64

CAT II Other than stand. CAT II Lower than stand. CAT I

CAT III A

3 consecutive lights of : – the centre line of the approach lights, – or the touchdown zone lights, – or the runway centreline lights, – or the runway edge lights, – or a combination of these

X

X

A lateral element of the ground pattern: – Approach lighting cross bars, – or threshold – or barrettes of the TDZ

X

Visual references

Table E1: visual references vs. approach categories

If the RVR is at the minimum value of the approach category (300m for CAT II, 200m for CAT IIIA) the visual segment at the decision height should be as shown on the drawings below:

Zone obscured by fog

Visual segment

Zone obscured by aircraft nose

Figure E9: Visual references at 100ft with 300m RVR

Figure E10: Visual references at 50ft with 200m RVR

6.7. Loss of visual references below DH Before touchdown, when the decision to continue has been made, if the visual references subsequently become insufficient, or if the flight path deviates unacceptably, a go-around must be initiated.

7. Abnormal procedures 7.1. General There are three possible responses to the failure of any system, instrument or element during a low visibility approach. – Continue the approach to the planned minima, – Continue the approach to higher minima and proceed to a new DH or DA, – Go-around, reassess the capability and consider a new approach or a diversion. The nature of the failure and the point of its occurrence will determine which response is appropriate.


p. 65


7.2. Failure treatment concept In the Operations Manual, each operator has to develop its own abnormal procedures, in agreement with its Authority. ATR recommends that any failure occurring during a low visibility approach be treated in accordance with the following general rule: Q If

associated actions, checklist and assessment are completed before reaching 800ft RA: – The approach can be continued to the planned minima if the failure does not affect the aircraft capability, – The approach can be continued to higher minima if the failure allows reversion from CAT II, lower than Standard CAT I, other than Standard CAT II to CAT I or from CAT III to CAT II or CAT I. In such cases the reported RVR must be above the new category’s minima; a short briefing is made and the new DH or DA is set. – If none of the previous situations apply, a go-around is performed and a diversion is considered

Q If

associated actions, checklist and assessment are not completed before reaching 800ft RA or if failure occurs below 800ft RA – A go-around is performed, the aircraft capability is reassessed and according to the weather conditions, the flight crew decides to perform a new approach or to divert.

It has been considered that below 800ft, not enough time is available for the crew to perform the necessary switching, to check system configuration and limitations and brief for minima. Nevertheless if visual references are obtained at the time of failure’s occurrence the Captain may decide to continue the approach considering the aircraft position and the kind of failure. The operator policy may also decide to make some exemption to this general rule for some very specific events (engine fire, smoke in the cabin…) where it may be considered preferable (Captain decision) to continue the approach.

The failure treatment is completed before 800ft RA and

CAT II / III capability is not affected

£

CAT II/III approach is continued

CAT II / III capability is affected Reversion to higher minima is possible

£

Approach is continued to higher minima

CAT II/III capability is affected £ Reversion to higher minima is not possible

Go-around

800ft RA

The failure treatment is not completed before 800ft RA

Go-around Go-around

The failure occurs between 800ft RA and DH

DH The failure occurs below DH £ Captain decision to land or to go-around according to the type of failure, the visual references and the aircraft position

Figure E11: Failure treatment logic during CAT II/III approaches

7.3. Failure treatment on classic instruments ATR Guidance material is available in the Aircraft Flight Manuel on the effect of some failures during a CAT II approach (please refer to Paragraph C.4, Aeroplane malfunctions).


p. 66

Those failures and their associated procedures have to be developed in details in the airline’s Operations Manual. A summary is given hereunder: Q Failures

for which a reversion to CAT I minima is possible if failure has been completely treated before reaching 800ft (considering CM1 is PF): – Flaps failure (jammed between 0 and 15°) – Engine failure – Failure of two MFC modules – Flag on standby horizon – Radio altimeter – EFIS COMP -ATT/PIT/ROLL warning on any EFIS – EFIS COMP - HDG warning on any EFIS – EFIS COMP - LOC/GS/ILS warning on any EFIS – Loss of both CRT on one side (SGU failure) – Loss of Airspeed indicator 1 or 2 – Loss of Altimeter 1 or 2 – AP disengagement (with impossibility to recover) – Loss of ADU – Loss of CAT II capability (with impossibility to recover)

Q Failures

which do not prevent continuation of the approach to CAT II minima if the failure has been completely treated before reaching 800ft: – Flaps failure (jammed above 15°) – Hydraulic failure without fluid loss (blue and green circuit available) – Failure of one MFC module – Loss of one CRT – Master Caution or Master Warning for any other event which do not cause one of the failure or warning address here above chapter E.7.2 and E.7.3.

Comments Q ATR

aircraft are not certificated for CAT II approaches with one engine out; nevertheless in conditions equal or better than CAT I, a single engine approach can be performed with the autopilot engaged.

Q The

STBY horizon must be operative during a CAT II approach because in case of: – CAT II INVALID message, – excess deviation (please refer to Paragraph E.7.5, Maximum ILS deviation allowed), – AFCS failure, – EFIS COMP, a Go-around must be performed by using the STBY horizon with an initial missed approach pitch of 10°. Q RA

Failure: If the radio altimeter fails, amber dashes replace the digital display, and the rising runway (if displayed) is removed.

Q The

ADU must be operative for the display on it of CAT II capability and “CAT II INVALID” messages.

7.4. Failure treatment on ATR -600 For later revision.

7.5. Maximum ILS deviation allowed As for any approach, in case of flight parameters’ deviation, the PNF must make the appropriate calls: DEVIATION

CALLs

IAS: +10 Kts / –5 Kts

speed

Bank angle >10°

bank

Pitch attitude: ± 4°

pitch


p. 67


The excessive ILS deviation monitor is active during dual coupled Category II approaches. Glideslope deviation is monitored between 500 feet and 100 feet AGL, and localizer deviation is monitored between 500 feet and 0 feet AGL. Excessive deviation threshold Localizer

1/3 dot

Glideslope

3/4 dot

On classic instruments ATR, if excessive deviation is detected, the associated scale and pointer turn amber and flash and the message EXCESS DEV is displayed on the ADU. If installed, the Guidance warning light located in the primary field of view of the pilot is also triggered. If this warning occurs during a CAT Il, CAT III, other than Standard CAT II or lower than Standard CAT I approach, the PNF announces “Deviation” or “Guidance” and the PF initiates a go-around except provided that visual references are sufficient.

8. Effects of failure of ground equipment Aerodrome facilities are expected to be installed and maintained to the prescribed standards in ICAO annexes 10 and 14. Any deficiencies are expected to be repaired without unnecessary delay. If the failure can not be fixed and concerns the ILS, the lighting, or the RVR measurement equipment, the general rule for the crew is to consider that the CAT II or CAT III approach is no longer available. Nevertheless and depending on the operational regulation applied, it may be accepted that a simple or partial failure does not prevent a low visibility approach or merely leads to increased minima. As an example, the table here below shows the effect of failure of ground equipment for operators applying the European regulation:

Failed or downgraded equipment Approach lights Approach lights except the last 210m

EFFECT ON LANDING MINIMA CAT IIIA

CAT II

Not allowed for operations with DH>50ft

Not allowed

No effect

Not allowed

Approach lights except the last 420m

No effect

Standby power for approach lights

No effect

Whole runway light system Edge lights Centreline lights

Not allowed Day only / Night – not allowed Day – RVR 300m Night – not allowed

Centreline lights spacing increased to 30m Touchdown zone lights

No effect Day – RVR 300m / Night – RVR 550m

Standby power for runway lights Taxi light system ILS standby transmitter

Day – RVR 300m Night – RVR 550m

Not allowed No effect- except delays due to reduced movement rate Not allowed

No effect

Outer marker

No effect if replaced by published equivalent position

Middle marker

No effect

Touch Down Zone RVR assessment system Midpoint or stopend RVR Anemometer for Rwy in used Celiometer

May be temporarily replaced with midpoint RVR if approved by the State of the aerodrome. RVR may be reported by human observation No effect No effect if other ground source available No effect


p. 68

NOTE:

– Multiple failures of runway lights other than indicated in this table are not acceptable. – Deficiencies of approach and runway lights are treated separately. – A combination of deficiencies in runway lights and RVR assessment equipment is not allowed. – Failures other than ILS affect RVR only and not DH.

This table is intended for use both pre-flight and in-flight. It is not expected however that the commander would consult such instructions after passing the outer marker or equivalent position. If failures of ground aids are announced at such a late stage, the approach could be continued at the commander’s discretion. If however failures are announced before such a late stage in the approach, their effect on the approach should be considered as described in the table, and the approach may have to be abandoned to allow this to happen.


p. 69

F. Flight crew training and qualification

F - Flight crew training and qualification 7B$75B$:2FKDSWHU$WR*PD\LQGG

p. 70

1. General Operators must provide appropriate training and qualification for each pilot intended to perform Low Visibility Operations. Training and crew qualification programs should include provisions for appropriate ground training, simulator training, and recurrent training. Flight crew members are expected to have a comprehensive level of knowledge with respect to each of the ground training subjects. During the simulator training pilots are expected to perform the relevant procedures or applicable manoeuvers and must demonstrate having the skill to perform their assigned duties. The training program must be related to the aeroplane type, to the particular airborne system and to the operating procedures adopted by the operator. Operational regulation establishes the minimum content of those training program. ICAO, FAA and EASA regulations are quite similar. Training and qualification program provided in the following paragraph is based on EASA requirements. Each flight crew member must have successfully completed this training and qualification program prior to conducting: – Low visibility take-offs in less than 150m RVR – Lower than Standard Category I approaches – Other than Standard Category II approaches – CAT II and CAT III approaches

2. Ground training It is the operator’s duty to establish a ground course to ensure flight crew understands the specific environment of Low Visibility Operations and that they have a good knowledge of characteristics and limitations of both ground and airborne equipment. The European regulation requests that at least the following items be covered (cf. Appendix 1 to EU-OPS 1.450 (b)). 1. The characteristics and limitations of the ILS and/or MLS. Please refer to Paragraph D.5

2. The characteristics of the visual aids. Please refer to Paragraph D.6

3. The characteristics of fog. Please refer to Paragraph B.1

4. The operational capabilities and limitations of the particular airborne system. Please refer to Paragraphs C.1 & C.2

5. The effects of precipitation, ice accretion, low-level windshear and turbulence. Please refer to Paragraph B.2

6. The effects of specific aircraft malfunctions. Please refer to Paragraph C.4

7. The use and limitations of RVR assessment system. Please refer to Paragraph B.3

8. The principles of obstacle clearance requirement. Please refer to Paragraph D.4

9. Recognition of and action to be taken in the event of failure of ground equipment. Please refer to Paragraph E.8. 10. The procedures and precautions to be followed with regard to surface movement during operations when the RVR is 400m or less and any additional procedures required for take-off in conditions below 150m. Please refer to Paragraphs E.3 & E.4

11. The significance of decision heights based upon radio altimeters and the effect of terrain profile in the approach area on radio altimeter readings and on the automatic approach/landing system. Please refer to Paragraph D.3

13. The qualification requirements for pilots to obtain and retain approval to conduct Low Visibility Take-Off and CAT II and CAT III operations. Please refer to Chapter F

14. The importance of correct seating and eye position. Please refer to Paragraph E.5.7

Flight crew members with previous CAT II or CAT III experience with the operator or with another European operator may undertake an abbreviated ground training course.


p. 71


3. Simulator training and checking 3.1. Full training program Each flight crew member must be trained to carry out his/her duties appropriate to the particular airborne system as well as be instructed on the coordination required with other crew members. Maximum use should be made of flight simulators capable of performing the specified manoeuvers, and which can appropriately represent the limiting visual conditions related to the applicable minima. EASA requirements are detailed in Appendix 1 to EU-OPS 1.450 (c & f). The main outlines of this document are explained here below: Training must be divided into phases covering normal operations with no aeroplane or equipment failure but including all weather conditions which may be encountered and detailed scenarios of aeroplane and equipment failures which could affect Category II or III operations. The initial simulator training program for Low Visibility Operations must include the following items (1 to 7) and the following exercises (8 to 19): 1. checks of satisfactory functioning of equipment, both on the ground and in flight; 2. effect on minima caused by changes in the status of ground installations; 3. monitoring of automatic flight control systems and autoland status annunciators with emphasis on the action to be taken in the event of failures of such systems; 4. actions to be taken in the event of failures such as engines, electrical systems, hydraulics or flight control systems; 5. the effect of known unserviceabilities and use of minimum equipment lists; 6. operating limitations resulting from airworthiness certification; 7. guidance on the visual cues required at DH together with information on maximum deviation allowed from glidepath or localizer; 8. approach using the appropriate flight guidance, autopilots and control systems installed in the aeroplane, to the appropriate decision height and to include transition to visual flight and landing; 9. approach with all engines operating using the appropriate flight guidance systems, autopilots, and control systems installed in the aeroplane down to the appropriate decision height followed by missed approach; all without external visual reference; 10. where appropriate, approaches utilising automatic flight systems to provide automatic flare, landing and rollout; 11. normal operation of the applicable system both with and without acquisition of visual cues at decision height; 12. approaches with engine failure at various stages on the approach; 13. approaches with critical equipment failures (e.g. electrical systems, auto flight systems, ground and/or airborne ILS/MLS systems and status monitors); 14. approaches where failures of auto flight equipment at low level require either; – reversion to manual flight to control flare, landing and roll out or missed approach; or – reversion to manual flight or a downgraded automatic mode to control missed approaches from, at or below decision height including those which may result in a touchdown on the runway; 15. failures of the systems which will result in excessive localizer and/or glide slope deviation, both above and below decision height, in the minimum visual conditions authorized for the operation. 16. failures and procedures specific to aeroplane type or variant. 17. practice in handling faults which require a reversion to higher minima. 18. handling of the aeroplane when, during a fail passive Category III approach, the fault causes the autopilot to disconnect at or below decision height when the last reported RVR is 300 m or less. 19. incapacitation procedures appropriate to Low Visibility Take-Offs and Category II and III operations. 20. take-offs with RVRs of 400 m and below: systems failures and engine failure resulting in continued as well as rejected take-offs.


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21. take-offs in RVRs below 150 m: – normal take-off in minimum authorised RVR conditions; – take-off in minimum authorised RVR conditions with an engine failure between V1 and V2, and – take-off in minimum authorised RVR conditions with an engine failure before V1 resulting in a rejected take-off.

Example of LVO syllabus for initial training on classic instruments ATR LVO Nb 1

Partial time

Total time

RVR 125m RVR 300m, ceiling 120ft Simulator freeze at 100ft / 50ft – view of visual references in day, dusk and night condition

0h25

0h25

LVO EXERCISES

REMARKS

LVTO - radar vectoring Full CAT II briefing CAT II approach / freeze at DH / landing

2

Repositioning base leg CAT II approach - landing

RVR 300m; ceiling 120ft

0h10

0h35

3

LVTO - radar vectoring Full CAT II briefing CAT II approach No visual reference – Go around

RVR 125m RVR 300m, ceiling 120ft RVR 300m, ceiling 50ft Engine failure at go around

0h25

0h55

4

Engine restart in down wind CAT II approach F/O decision / Go around

RVR 300m, ceiling 120ft Captain incapacitation at 1300ft Research of diverting airport

0h15

1h10

5

Radar vectoring to base leg CAT II approach Captain decision Go around with STBY horizon

RVR 300m, ceiling 120ft At 500ft: Drift roll EADI

0h15

1h25

6

Radar vectoring to base leg CAT II approach Go around

RVR 300m, ceiling 120ft auto-pilot failure at 400 ft

0h15

1h40

7

Repositioning to base leg CAT II approach Reversion to CAT I - Landing

Flaps jam 15° at 2000ft RVR 550m ceiling 220ft

0h10

1h55

8

LVTO Aborted take off

RVR 125m Engine failure before V1

0h05

2h00

0h05

2h05

9

LVTO FO’s decision – carrying on T/O

RVR 125m Captain incapacitation at 90kts

0h05

2h10

10

Radar vectoring CAT II approach Excess deviation - Go around

RVR 300m, ceiling 120ft LOC deviation at 200ft

0h15

2h25

11

Radar vectoring to base leg Procedure and C/L CAT I approach- landing

RVR 400m, RA failure at 2000ft RVR 550m ceiling 220m Reversion to CAT I

0h20

2h45

12

LVTO

RVR 125m – ceiling 120m Engine failure between V1&V2 Engine restart- RVR 300m “CAT 2 invalid” at 800ft

0h20

3h05

15

3h20

BREAK

Radar vectoring to base leg CAT II approach - Go around 13

Radar vectoring to base leg CAT II approach Captain decision – go around

RVR 300m, ceiling 120ft ADC failure at 500ft


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14

Repositioning 10Nm CAT II approach Captain decision – go around

RVR 300m, ceiling 120ft Loss of ADU at 1500ft

10

3h30

15

Repositioning 10Nm final CAT II approach Captain decision – go around

RVR 300m, ceiling 120ft Loss STBY horizon at 1200ft

10

3h40

16

Radar vectoring CAT II approach Captain decision: app. Continued Captain decision : landing

RVR 300m, ceiling 120ft FO’s EADI failure at 1200ft

20

4h00

Engine fire at 400ft

Example of LVO syllabus for initial training on ATR -600 For later revision.

3.2. Training for flight crew members with Category II or Category III experience The flight simulator course may be abbreviated for flight crew members who gained Category II/III experience with: – another European Community Operator through a similar type of operation (auto coupled/auto-land or Category II with manual land) on the same type and variant of aeroplane or – the operator but on a different type or variant of aeroplane. The abbreviated flight simulator course consists of a minimum of six approaches and/or landings in a flight simulator. With the approval of the Authority the operator may reduce this number of approaches/landings. More details on conditions allowing abbreviating the flight simulator course are given in Appendix 1 to EU-OPS 1.450 (a&d).

3.3. Training for flight crew members flying on classic instruments ATR and on ATR -600 For later revision.

3.4. Flight crew qualification Following completion of ground and simulator training, flight crew members must demonstrate their competency to the appropriate authorities. Each pilot undergoes a check before conducting Category II/III operations and/or Low Visibility Take-Off with RVR below 150m. This check may be replaced by successful completion of the flight simulator training prescribed here above.

4. Line training Once the simulator training and checking program has been completed, each flight crew member undergoes the following line flying under supervision (LIFUS) before initiating Category II or III approaches: (cf. Appendix 1 to EU-OPS 1.450 d (4)) Q For

Category II when a manual landing is required, a minimum of three landings from autopilot disconnect; except that only one manual landing is required when the flight simulator training required has been carried out in a flight simulator qualified for zero flight time (ZFT) conversion.


p. 74

Q For

Category III, a minimum of two auto lands except that only one autoland is required when the flight simulator training has been carried out in a flight simulator qualified for zero flight time conversion… (see also (d) ii B App 1 EU-OPS 1.450 for flight crew members who have completed a ZFT type rating conversion course)

5. Type and command experience Before a pilot may be authorised to operate with Category II or III minima, that pilot must have gained sufficient flight experience on the aeroplane type before being authorized to apply Category II or III operating minima under actual conditions. EASA requirements concerning flight experience can be summed up as follows: (cf. Appendix 1 to EU-OPS 1.450 (e)) Before commencing Category II or III operations, the following additional requirements are applicable to commanders, or pilots to whom conduct of the flight may be delegated, and who are new to the aeroplane type: – 50 hours or 20 sectors on the type, including line flying under supervision; and – 100 m must be added to the applicable Category II or Category III RVR minima until a total of 100 hours or 40 sectors, including LIFUS has been achieved on the type. Those requirements may be reduced for flight crew members who have previously been qualified for Category II/ III operations with a Community operator or who have CAT II/III command experience. See details in Appendix 1 to EU-OPS 1.450 (e).

6. Recurrent training and checking At fixed intervals, a recurrent training program should take place to ensure and maintain an adequate level of proficiency for Low Visibility Operations qualified pilots. In conjunction with the normal operator proficiency checks, a pilot’s knowledge and ability to perform the tasks associated with Low Visibility Operations must be demonstrated. Under European regulation (cf. Appendix 1 to EU-OPS 1.450 (g)), the required number of approaches to be undertaken in the flight simulator within the validity period of the operators proficiency check (6 month) is to be a minimum of two: – one must be a landing at the lowest approved RVR; – one may be substituted by an approach and landing in the aeroplane using approved Category II and III procedures. In addition, during the conduct of the operators proficiency check, one missed approach must be flown. If the operator is authorised to conduct take-off with RVR less than 150 m, at least one LVTO to the lowest applicable minima shall be flown during the conduct of the operators proficiency check. Recency for LTVO and Category II/III based upon automatic approaches and/or auto-lands is maintained by recurrent training and checking, as prescribed in this paragraph.


p. 75


7. The qualification process of flight crew under EASA regulation: overview Flight crew without CAT II/III experience

Flight crew with CAT II/III experience: – with other operator & – on different type

Flight crew with CAT II/III experience: – with other operator & – same type of operation on same type and variant

Flight crew with CAT II/III experience: – with same operator on different type or variant

GROUND TRAINING

GROUND TRAINING

GROUND TRAINING

GROUND TRAINING

Full ground training course

Abbreviated ground training course



SIM. TRAINING – Full Simulator training course – Simulator check

SIM. TRAINING – Abbreviated simulator training course – Simulator check

SIM. TRAINING – Full Simulator training course – Simulator check

LINE TRAINING Manual CAT II : 3 landings (1 if training on ZFT simulator) Autoland CAT III: 2 autoland (1 if training on ZFT simulator)

COMMANDER with

COMMANDER with

– 50h on type or – 20 sectors

– 100h on type or – 40 sectors

Qualification to CAT II/III approaches with RVR minima +100ft

SIM. TRAINING – Abbreviated simulator training course – Simulator check

Qualification for LVTO with RVR below 150m

FIRST OFFICER

QUALIFICATION FOR CAT II/III APPROACHES to the lowest minima


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G. Operator’s duties

G - Operator’s duties 7B$75B$:2FKDSWHU$WR*PD\LQGG

p. 77


1. Establishing operating minima 1.1. General Aerodrome operating minima are defined as the limits of usability of an aerodrome for either take-off or landing. They are established in order to ensure a desired level of safety for aeroplane operations at an aerodrome by limiting these operations in specified weather conditions. It’s the operator’s responsibility to establish aerodrome operating minima for each aerodrome to be used in operations. In determining the values of operating minima, the operator must take into account. (cf. ICAO Annex 6 § 4.2.7.2) The type, performance and handling characteristics of the aeroplane; Q the

composition of the flight crew, their competence and experience;

Q the

dimensions and characteristics of the runways which may be selected for use;

Q the

adequacy and performance of the available visual and non-visual ground aids;

Q the

equipment available on the aeroplane for the purpose of navigation and/or control of the flight path during the approach to landing and the missed approach;

Q the

obstacles in the approach and missed approach areas and the obstacle clearance altitude/height for the instrument approach procedures;

Q the

means used to determine and report meteorological conditions; and

Q the

obstacles in the climb-out areas and necessary clearance margins.

Take-off operating minima are expressed in terms of RVR / visibility. For low visibility approach, operating minima are expressed as an RVR associated to a DH. DH is the minimum height in an approach by which a missed approach must be initiated if the required visual reference to continue the approach has not been established. DH value is established taking into account: – the characteristics of the aeroplane and its equipment (i.e. minimum DH specified in the AFM), – obstacles in the approach and missed approach area (i.e. obstacle clearance height) – the performance of the approach aid (ILS), – the category of operations. The RVR associated to a Decision Height is intended to provide a high probability that the required visual references will be available at that decision height. The RVR is established taking into account: – the DH value: As a general rule, the higher the aeroplane is at DH, the greater will the RVR required be (please refer to Paragraph B.3.3, RVR use)

– the lighting system characteristics, – the tasks the pilot is required to carry out at and below DA/H in order to complete the landing (manual landing or monitoring of an autoland). Nevertheless, aerodrome minima established in that way by the operator must not be lower than: – minima that may be established by the State in which the aerodrome is located, – DH and RVR minimum values imposed by the operator’s authority through a specific authorisation, or more generally through the applicable operational regulation. NOTE: Minima on their own have no intrinsic meaning; they only have significance in conjunction with a set of operating policies, procedures and pilot training program. For this reason, the imposition of specific operating minima by the State of the Aerodrome on operators from another State can lead to inconsistencies or be counter-productive. For example, a European operator who has implemented low visibility operational procedures and a pilot training program, as described in Chapter E and F, can use the minimum DH and RVR required by EASA regulation, except if the State of the aerodrome where operations take place has published higher minima.


p. 78

1.2. EASA take-off minima Please refer to EU-OPS 1.430, Appendix 1 (a) - Take-off Minima

The take-off minima established by an operator must be expressed as RVR/Visibility values not lower than: Take off RVR / visibility RVR / visibility for ATR aircraft(1)

Facilities Nil (day only)

500m 250m(2)

Runway edge lighting and/or centreline markings Runway edge and centreline lighting

200m 150m(3)

Runway edge and centreline lighting and multiple RVR information (1)

The reported RVR/Visibility value representative of the initial part of the take-off run can be replaced by pilot assessment. (2) For night operations at least runway edge and runway end lights are required. (3) The required RVR value must be achieved for all of the relevant RVR reporting points with the exception cited (1) above.

Subject to approval from the relevant Authority, and provided additional conditions are satisfied, the take-off minima may be reduced to 125 m (please refer to Paragraph E.4.2, Low Visibility Take-Off under European regulation (EU-OPS) ).

1.3. EASA CAT II minima Please refer to EU-OPS 1.430, Appendix 1 (a) - Take-off Minima Q The

Decision Height for CAT II operations must not be lower than:

– the minimum decision height specified in the AFM (100ft for all ATR series); or – the minimum decision height to which the precision approach aid can be used without the required visual reference; or – the Obstacle Clearance Height (OCH- see paragraph D4) for the category of aeroplane; or – the Decision Height to which the flight crew is authorised to operate; or – 100ft (30m). NOTE: CAT II approaches are “auto-coupled” approaches to below DH. The automatic flight control system must be used down to a height which is not greater than 80% of the applicable DH. Thus airworthiness requirements may, through minimum engagement height for the automatic flight control system, affect the DH to be applied. For ATR aircraft, as the minimum height for the use of autopilot in approach mode is 80 ft (50ft for Aircraft with Mod 0069), there is no limitation for the use of a DH equals to 100ft. Q The

required RVR depends on the DH value as follows: Decision height

RVR for Cat B aircraft (ATR)

100ft – 120ft

300m

121ft- 140ft

400m

141ft and above

450m

1.4. EASA CAT III minima Please refer to EU-OPS 1.430, Appendix 1 (g) - Precision approach - Category III operations. Q The

Decision Height for CAT III operations must not be lower than:

– the minimum decision height specified in the AFM, (50ft for ATR -600); or – the minimum height to which the precision approach aid can be used without the required visual reference; or – the decision height to which the flight crew is authorised to operate. Q The

minimum RVR required for CAT IIIA approaches with a DH less than 100ft is 200m.


p. 79


1.5. EASA Lower than Standard CAT I minima Please refer to EU-OPS 1.430, Appendix 1 (e) - Lower than Standard Category I operations Q The

Decision Height for lower than Standard CAT I operations must not be lower than:

– the minimum decision height specified in the AFM, if stated; – the minimum height to which the precision approach aid can be used without the required visual reference; or – the OCH for the category of aeroplane; or – the decision height to which the flight crew is authorised to operate; or – 200 ft. Q The

required RVR depends on the DH value as follows: Class of lighting facility DH (ft)

FALS

IALS

BALS

NALS

RVR/CMV(1) (metres)

(1)

200 - 210

400

500

600

750

211 - 220

450

550

650

800

221 - 230

500

600

700

900

231 - 240

500

650

750

1000

241 - 249

550

700

800

1100

CMV: Converted Meteorological Visibility (please refer to Paragraph B.3.5, Conversion of reported meteorological

visibility to RVR).

The visual aids required to conduct lower than Standard Category I Operations comprise: – standard runway day markings and – runway lighting (runway edge lights, threshold lights, runway end lights). – approach lighting (for FALS, IALS, BALS and NALS definitions, please refer to Paragraph D.6.3) and, – touch-down zone and/or runway centre line lights for operations below 450m.

1.6. EASA other than Standard CAT II minima Please refer to EU-OPS 1.430, Appendix 1 (f) - Precision approach: Category II and other than Standard Category II Q The

DH is established as for Category II approaches (see here above)

Q The

required RVR depends on the DH value as follows: Class of lighting facility DH (ft)

FALS

IALS

BALS

NALS

RVR (meters) 100 - 120

350

450

600

700

121 - 140

400

500

600

700

141 - 160

450

500

600

750

161 - 199

450

550

650

750

The visual aids required to conduct other than Standard Category II Operations comprise: – standard runway day markings and – runway lighting (runway edge lights, threshold lights, runway end lights). – approach lighting ( for FALS, IALS, BALS and NALS definitions, please refer to Paragraph D.6.3) and – centre line lights for operations in RVR of 400 m or less.


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1.7. Operating minima publication For standard operations, a large number of operators decides to use operating minima published on Jeppesen approach charts. Minima published by Jeppesen are the minimum values allowed by the operational regulation prevailing in the concerned region of the world. Concerning Low Visibility Operations, Jeppesen documentation can also be used for Low Visibility Take-Off (please refer to Paragraph E.4.2) and for CAT II approaches (see figure 56 here below). Concerning lower than Standard CAT I, other than Standard CAT II and CAT III approaches, Jeppesen does not publish any operating minima. It is the operator responsibility to publish minima for these operations.

Figure G1: Example of CAT II minima on a Jeppesen approach chart

2. Operations manual content In their Operations Manual, operators must publish all relevant information, procedures and operating instructions relating to Low Visibility Operations. Instructions must be compatible with the limitations and mandatory procedures contained in the Aeroplane Flight Manual. The implementation of Low Visibility Operations will generally affect different parts of the Operations manual, depending on the general structure of the document. Q The

general/basic part which contains non type-related operational policies should include a chapter concerning Low Visibility Operations: this chapter should address the following matters: – definition of Low Visibility Operations (please refer to Paragraph A.5, Definitions), – regulatory framework (please refer to Paragraph A.4, Relevant regulations), – general conditions on aircraft, crew and ground equipment (please refer to Paragraph A.3, Low visibility operations (LVO) concept), – rules for the determination and use of operating minima (please refer to Paragraph G.1, Determination of operating minima), – rules for the commencement and continuation of approach (please refer to Paragraph E.6.2, Approach ban / RVR controlling), – use of weather report and RVR controlling (please refer to Paragraphs B.4, Weather Documentation and E.6.2, Approach ban / RVR controlling), – minimum visual references (please refer to Paragraph E.6.4, Normal procedures on classic instruments ATR for CAT II approaches), – effects of ground equipment failure (please refer to Paragraph E.8, Effects of ground equipment failure).

Q The

section on the Aeroplane operating matters comprises all type-related instructions and procedures. It should contain aircraft limitations plus detailed operating procedures which must include the description of flight crew member duties during take-offs, approaches, flares, roll-outs and missed approaches. Special attention must be paid to task sharing in conjunction with the workload of each crew member. Particular emphasis must be placed on flight crew responsibilities during transition from non-visual conditions to visual conditions, and on the procedures to be used in deteriorating visibility conditions or when failures occur. The given instructions depend on which airborne equipment is used and on which flight deck procedures are being followed (please refer to Chapter E, Flight crew operating procedures).


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Q The

Training part should describe in detail the flight crew training and qualification process and the recurrent training and checking program (please refer to Chapter F, Flight Crew Training and qualification).

For European operators, Appendix 1 to EU-OPS 1.455 (b) lists the different items to be covered by the operations manual: (i) checks for the satisfactory functioning of the aeroplane equipment, both before departure and in flight (please refer to § C3, E2, E5)

(ii) effect on minima caused by changes in the status of the ground installations and airborne equipment (please refer to § C3, C.4, E8)

(iii) procedures for the take-off, approach, flare, landing, roll-out and missed approach (please refer to § E3, E4, E5, E6)

(iv) procedures to be followed in the event of failures, warnings and other non-normal situations (please refer to § E7)

(v) the minimum visual reference required (please refer to § E.6.4); (vi) the importance of correct seating and eye position (please refer to § E.5.7); (vii) action which may be necessary arising from a deterioration of the visual reference (please refer to § E.6.5); (viii) allocation of crew duties in the carrying out of the procedures according to subparagraphs (i) to (iv) and (vi) above, to allow the Commander to devote himself/herself mainly to supervision and decision making (please refer to § E.6.3); (ix) the requirement for all height calls below 200 ft to be based on the radio altimeter and for one pilot to continue to monitor the aeroplane instruments until the landing is completed (please refer to § E.6.1); (x) the requirement for the Localizer Sensitive Area to be protected (please refer to § D.5.4 & E.5.1); (xi) the use of information relating to wind velocity, wind shear, turbulence, runway contamination and use of multiple RVR assessments (please refer to § B.2, B.3, B.4, E.5.1, E.6.2); (xii) procedures to be used for: (A) lower than Standard Category I; (B) other than Standard Category II; (C) practice approaches and landing on runways at which the full Category II or Category III aerodrome procedures are not in force (please refer to § E.6); (xiii) operating limitations resulting from airworthiness certification and (please refer to § C.1, C.2)

(xiv) information on the maximum deviation allowed from the ILS glide path and/or localizer (please refer to § E.7.5).

3. Operational demonstration 3.1. General Operational regulation (cf. AC 120-29A / AC 120-28D §10.5 and Appendix 1 to EU-OPS 1.440) compel operators to carry out an operational demonstration before being authorised to perform CAT II/III approaches. The aircraft system suitability is demonstrated through the initial airworthiness demonstration. The aim of the operational demonstration is not to repeat the flight test program performed for the CAT II/III airworthiness approval. It is to determine or validate the use and effectiveness of the aircraft flight guidance systems, training, flight crew procedures, maintenance program, and manuals applicable to the program being approved.


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In practice the operational demonstration consists in performing a number of approaches in CAT I or better weather conditions using Category II/III systems and procedures. Such demonstration may be conducted in line operations, during training flights or during aircraft type or route proving runs. The flight crew involved in this demonstration must have completed his low visibility ground and simulator training. Approaches and landings performed during this demonstration must be recorded through a data collection method (e.g. a form to be used by the flight crew) to establish that performances and reliability in line service are suitable. EU-OPS 1.440 - Appendix 1: Low visibility operations — General operating rules AC 120-28 and -29 Paragraph 10.5.2 – “Operator Use Suitability” Demonstration If an operator has different variants of the same type of aircraft utilising the same basic flight control and display systems, or different basic flight control and display systems on the same type of aircraft, the operator must [FAA: shoud] show that the various variants have satisfactory performance, but the operator need not conduct a full operational demonstration for each variant.

3.2. Operational demonstration under European regulation The EU regulation (cf. Appendix 1 to EU-OPS 1.440 b) requests that for CAT II/III operations with a DH of 50ft or higher, at least 30 approaches and landings be accomplished in operations to validate the operational demonstration. A reduction in the required number of landings may be considered on a case-by-case basis if justification is provided to the authority. If the number of unsuccessful approaches exceeds 5% of the total (e.g. unsatisfactory landings, system disconnects) the evaluation program must be extended in steps of at least 10 approaches and landings until the overall failure rate does not exceed 5%. Unsatisfactory approaches and/or automatic landings shall be documented and analysed. The resulting data and a summary of the demonstration data should be made available to the operational Authority.

Data Collection for Operational Demonstrations IEM Appendix 1 to EU-OPS 1.440 Data should be collected whenever an approach and landing is attempted utilising the Category II/III system, regardless of whether the approach is abandoned, unsatisfactory, or is concluded successfully. Not more than 30% of the demonstration flights should be made on the same runway. The data should, as a minimum, include the following information: – Inability to initiate an Approach: Identify deficiencies related to airborne equipment which preclude initiation of a Category II/III approach. – Abandoned Approaches: Give the reasons and altitude above the runway at which approach was discontinued or the automatic landing system was disengaged. – Touchdown performance: Describe whether or not the aircraft landed satisfactorily (within the desired touchdown area) with lateral velocity or cross track error which could be corrected by the pilot or automatic system so as to remain within the lateral confines of the runway without unusual pilot skill or technique. The approximate lateral and longitudinal position of the actual touchdown point in relation to the runway centreline and the runway threshold, respectively, should be indicated in the report. This report should also include any Category II/III system abnormalities which required manual intervention by the pilot to ensure a safe touchdown. Unsuccessful approaches due to the following factors may be excluded from the analysis: – ATS Factors: Examples include situations in which a flight is vectored too close to the final approach fix/ point for adequate localiser and glide slope capture, lack of protection of ILS sensitive areas, or ATS requests the flight to discontinue the approach. – Faulty Navaid Signals: Navaid (e.g. ILS localiser) irregularities, such as those caused by other aircraft taxiing, over-flying the navaid (antenna). – Other Factors. Any other specific factors that could affect the success of Category II/ III operations that are clearly discernible to the flight crew should be reported.


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EASA definition of a successful approach IEM Appendix 1 to EU-OPS 1.440 • From 500 feet to start of flare: – Speed is maintained as specified in AMC-AWO 231§ 2 (speed control); and – No relevant system failure occurs; and • From 300 feet to DH: – No excess deviation occurs; and – No centralised warning gives a go-around command (if installed).

EASA definition of a successful automatic landing IEM Appendix 1 to EU-OPS 1.440 No relevant system failure occurs; No flare failure occurs; No de-crab failure occurs (if installed); Longitudinal touchdown is beyond a point on the runway 60 meters after the threshold and before the end of the touchdown zone lighting (900 meters from the threshold); – Lateral touchdown with the outboard landing gear is not outside the touchdown zone lighting edge; – Sink rate is not excessive; – Bank angle does not exceed a bank angle limit; and – No roll-out failure or deviation (if installed) occurs. (More details can be found in CS-AWO 131, CS-AWO 231 and AMC-AWO 231) – – – –

3.3. Operational demonstration under FAA regulation The FAA regulation on operational demonstration is quite similar. The main difference concerns the number of approaches and landing to be carried out. At least 100 successful landings are required for the demonstration. Nevertheless a reduction in the required number of landings may be accepted by the authority on a case-by-case basis. AC 120-28 and -29 Paragraph 10.5.2 – “Operator Use Suitability” Demonstration. At least one-hundred (100) successful landings should be accomplished in line operations using the low visibility landing system installed in each aircraft type applicable to the Category II/ III authorisation. Demonstrations may be conducted in line operations, during training flights, or during aircraft type or route proving runs.

4. Eligible aerodromes and runways Operators must assess airports and runways eligible to perform Category III approaches. The purpose of this assessment is to check the compatibility between airborne and ground facilities to perform successful autoland. For Category II approaches such assessment is limited to specific situation in particular where the pre-threshold terrain profile may affect the conduct of the approach (please refer to Paragraph D.3. Effects of pre-threshold terrain profile). EU-OPS 1.440 - Appendix 1: Low visibility operations — General operating rules (h) Eligible aerodromes and runways 1. Each aeroplane type/runway combination must be verified by the successful completion of at least one approach and landing in Category II or better conditions, prior to commencing Category III operations. 2. For runways with irregular pre-threshold terrain or other foreseeable or known deficiencies, each aeroplane type/runway combination must be verified by operations in Standard Category I or better conditions, prior to commencing Lower than Standard Category I, Category II, or other than Standard Category II or Category III operations.


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5. Continuous monitoring After obtaining the authorisation to perform low visibility approaches, the operator must monitor the overall safety of those operations and monitor the automatic landing system performance of each aeroplane. The reporting of satisfactory and unsatisfactory Category II/III aircraft performance is a tool to detect any decrease in the level of safety before it becomes hazardous. Flight crew reports may be used to achieve this. If the analysis of those reports shows that conditions exist which could adversely affect safe Low Visibility Operations, the operator is expected to take appropriate corrective actions. Examples of appropriate corrective action could be an adjustment of Category II/III programs, procedures, training, modification to aircraft, restriction of minima, limitations on winds, restriction of NAVAID facility use, adjustment of payload, service bulletin incorporation, or other such measures necessary to ensure safe operation. Reported data and their analysis must be retained for a period of 12 months. It must include at least: (cf. Appendix 1 to EU-OPS 1.440(e)) Q the

total number of approaches, by aeroplane type, where the airborne Category II or III equipment was utilized to make satisfactory, actual or practice, approaches to the applicable Category II or III minima; and

Q reports

of unsatisfactory approaches and/or automatic landings, by aerodrome and aeroplane registration, in the following categories: – airborne equipment faults; – ground facility difficulties; – missed approaches because of ATC instructions; or – other reasons.

Such system for recording approach and/or automatic landing success and failure is requested by European regulation for Category II, other than Standard Category II, and Category III operations.

6. Operator approval process The approval process may differ according to the various regulations but the general principle consists in providing an operational approval file to the National Authority and in performing a specific sequence of actions in agreement with the Authority. Under European regulation, an operator cannot perform the following Low Visibility Operations unless approved by the Authority: – Low Visibility Take-Offs in less than 150m RVR; – Lower than Standard Category I approaches; – Other than Standard Category II approaches; – CAT II and CAT III approaches.

6.1. Prerequisite / transitional period The national Authority may request that an operator has operated an aeroplane type for a said-minimum period before granting an LVO approval. For instance, under EASA regulation, an operator must have gained a minimum experience of 6 months of Category I operations on the aeroplane type before being authorised to perform CAT II or CAT III approaches. Nevertheless an operator with previous CAT II/III experience (on another aeroplane type) may obtain authorisation for a reduced transition period.


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6.2. Operational approval file The operational approval file represents the official application for Low Visibility Operations. The aim of this file is to demonstrate to the authority that arrangements made by the operator comply with the relevant operational regulation on Low Visibility Operations. Basically, this file should include the following items. Q General

Presentation of the type of operations submitted to approbation (Category of approach, LVTO, special operations...), timetable for the implementation of LVO, previous experience with other aircraft type, lowest values of the operating minima established for the different categories of operations… Q Aircraft

status Extracts from the Aircraft Flight Manual addressing certification status for Low Visibility Operations, associated limitations, list of required equipment for the intended operations, normal procedures and procedures following failures. For ATR aircraft this information is provided in part 3 of the AFM.

Q Operating

procedures Copy of the amendment to the Operations manual covering Low visibility operations. Information and procedures to be introduced into the operation manual by an operator who intends to perform LVO are set out in paragraph G.2, Operations manual content. Details of operating procedures are addressed in Chapter E, Flight crew operating procedures.

Q Flight

crew training and qualification – Description of the flight crew training and qualification process according to the pilot’s previous experience (ground, simulator and line training, command experience, checking) including the process to qualify instructors. – Description of the recurrent training and checking. (please refer to Chapter F, Flight crew training and qualification)

Q Maintenance

program Description of the maintenance program, which is mandatory to ensure the airborne equipment will remain at the level of performance and reliability demonstrated during the certification (please refer to Paragraph C.5, Maintenance).

Q Aerodromes

List of aerodromes (if requested by the Authority) where the operator intends to perform Low Visibility Operations and demonstration that those aerodromes are eligible to such operations. (please refer to Paragraph G.4, Eligible aerodromes and runways) Q Operational

demonstration Presentation of the operational demonstration that the operator intends to perform including the data collection and analysis process. (please refer to Paragraph G.3, Operational demonstration)

Q Continuous

monitoring Description of procedures set up by the operator to monitor LVO performances after having obtained the initial authorisation. (please refer to Paragraph G.5, Continuous monitoring)

6.3. Sequencing of action during the approval process 1) The first step consists in obtaining acceptance of the file described here above by the National Authority. This may require several corrections or amendments involving multiple back and forth stage between the Authority and the operator. 2) As soon as the operating procedures, the training and qualification programmes are accepted by the Authority, ground and simulator training can be initiated. Some Authorities may request to supervise the first simulator sessions and/or the training and checking of instructors.


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3) Line training is initiated with flight crew members having completed their ground and simulator training. When approaches performed for line training are recorded they may be taken into account for the operational demonstration. 4) As and When: – the transitional period (please refer to Paragraph G.6.1, Prerequisite / transitional period) is over and

– the operational demonstration (please refer to Paragraph G.3, Operational demonstration) is completed with satisfactory results and

– the amendment to the operating manual covering Low Visibility Operations is effective, the National Authority should grant authorisation to perform LVOs 5) Low Visibility Operations can be initiated by the operator to the lowest minima with the possible limitation associated to the “type and command experience” (please refer to Paragraph F.5, Type and command experience) and to conditions on “eligible aerodromes and runways” (please refer to Paragraph G.4, Eligible aerodrome and runways). 6) Actions concerning the continuous monitoring must become effective. (please refer to Paragraph G.5, Continuous monitoring).


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Abbreviations ADU

Autopilot Display Unit

AFCS

Automatic Flight Control System

AGL

Above Ground Level

AHRS

Attitude & Heading Reference System

AP

Auto Pilot

ATC

Air Traffic Control

AWO

All Weather Operations

BALS

Basic Approach Light System

CRM

Collision Risk Model

CS

Certification Specifications

CM1

Left-seated Crew Member

CM2

Right-seated Crew Member

CMV

Converted Meteological Visibility

DH

Decision Height

EADI

Electronic Attitude Display Indicator

EASA

European Aviation Safety Agency

FAA

Federal Aviation Administration

FALS

Full Approach Light System

FD

Flight Director

GLS

GNSS Landing System

G/S

Glide Slope

HUDLS

Head-Up Display Landing System

IALS

Intermediate Approach Light System

ICAO

International Civil Aviation Organisation

ILS

Instrument Landing System

LOC

Localizer

LVO

Low Visibility Operations

LVP

Low Visibility Procedures

LVTO

Low Visibility Take-Off

METAR

Meteo Airport Report

MLS

Microwaves Landing System

NALS

No Approach Light System

OAS

Obstacle Assessment Surfaces

OCH

Obstacle Clearance Height

OFZ

Obstacle Free Zone

OLS

Obstacle Limitation Surfaces

OM

Outer Marker

PF

Pilot Flying

PNF

Pilot Non Flying

RA

Radio Altimeter

RVR

Runway Visual Range

SVR

Slant Visual Range

TAF

Terminal Aerodrome Forecast

TDZ

Touch Down Zone

Abbreviations 7B$75B$:2FKDSWHU$WR*PD\LQGG

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Dear Readers, Every effort has been made to ensure document quality. However please do not hesitate to share your comments and information with us by using the following address: [email protected] We would also like to thank ENAC (Ecole Nationale de l’Aviation Civile) for its involvement in the development of this guide. Yours faithfully,

Printed on 100% recycled paper using vegetable inks

Your ATR Training and Flight Operations support team.

© ATC June 2010 All reasonable care has been taken by ATC to ensure the accuracy of the present document. However this document does not constitute any contractual commitment from the part of ATC which will offer, on request, any further information on the content of this brochure. Information in this brochure is the property of ATC and will be treated as confidential. No use or reproduction or release to a third part may be made there of other than as expressely authorised by ATC.

7B$75B$:2BFRYHULQGGFRXY

FCTM All Weather Operations

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