AWOPs

ALL WEATHER OPERATIONS

Craig Pearce - January 2003

INDEX

1) WHAT IS AWOPs ? Page 2 ENR 1.8 : All Weather Operations Page 2

2) PLANNING IFR FLIGHTS INTO IMC Page 2 3) THE DEPARTURE AERODROME Page 2

CATS 121.07.7 / 135.07.7 : Take-off minima Page 3 General Page 3 Visual references Page 3 Required RVR / Visibility Page 3

4) QUESTIONS DEPARTURE AERODROME Page 5 5) LOW VISIBILITY PROCEDURES (LVPs) Page 8

ENR 1.8.3 : Low Visibility Procedures Page 8 Introduction Page 8 General Page 8 Localizer Sensitive Area Page 8 6) QUESTIONS LOW VISIBILITY PROCEDURES Page 9 7) TAKE-OFF ALTERNATE AERODROME Page 9 CAR 1.00.1 : Definition Page 9 CAR 91.07.7 : Pre-flight selection or aerodromes Page 10 CAR 91.07.8 : Planning minima for IFR flights Page 10 8) QUESTIONS TAKE-OFF ALTERNATE Page 11 9) DESTINATION AERODROME Page 12 CAR 91.07.8 : Planning minima for IFR flights Page 12 CATS 121.07.7 : Aerodrome operating minima Page 13 Non-precision approach Page 13 System minima Page 13 Minimum descent height Page 13

Visual reference Page 13 Required RVR Page 14

Precision approach Page 16 General Page 16 Decision height Page 16 Visual reference Page 16 Required RVR Page 17

10) QUESTIONS DESTINATION AERODROME Page 18 11) THE ALTERNATE AERODROME Page 19 CAR 91.07.8 : Planning minima for IFR flights Page 19 CATS 91.07.8 : Pre-flight selection of aerodromes Page 21 CAR 91.07.7 : Pre-flight selection of aerodromes Page 21 12) QUESTIONS DESTINATION ALTERNATE AERODROME Page 23 13) THE APPROACH BAN Page 24 ENR 1.8.2.6 : Commencement of an approach Page 25 14) QUESTIONS - THE APPROACH BAN Page 25 15) TOOLS TO ASSIST THE PILOTS Page 26 The monitored approach Page 26 The approach preperation Page 27 15) APPENDIX Page 28

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WHAT IS AWOPs ?

As the name implies, one would think that it would apply to all weather conditions, VMC and IMC, however, the definition below clearly states that AWOPs only applies to IFR flights in IMC conditions.

ENR 1.8.1.2.2 All weather operations Any take-off, en-route or landing operations in IMC and operated in accordance with IFR.

PLANNING IFR FLIGHTS INTO IMC Before any flight is operated in Instrument Meteorological Conditions, it is vital that the pilot checks the weather conditions at the aerodrome of departure, aerodrome of destination and all the required alternate aerodromes to ensure that the flight can be conducted legally and safely. It is also important to check the availability and serviceability of all the required facilities as this can affect the weather minimums required.

THE DEPARTURE AERODROME At the Aerodrome of Departure we need to check the following:

Facilities at aerodrome of departure to determine the take-off RVR / Visibility required.

Does the weather at the departure aerodrome preclude a return landing.

Depending on the facilities available at the Aerodrome of Departure, we can determine the required RVR / Visibility for take-off. This is achieved by perusing Civil Aviation Technical Standard (CATS) 121.07.7 (for large aircraft engaged in commercial air transport operation) or Civil Aviation Technical Standard (CATS) 135.07.7 (for small aircraft engaged in commercial air transport operation).

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CATS 121.07.7 / CATS 135.07.7 : Take-off minima (1) General

(a) Take-off minima established by the operator must be expressed as visibility or RVR limits, taking into account all relevant factors for each aerodrome planned to be used and the aeroplane characteristics. Where there is a specific need to see and avoid obstacles on departure and/or for a forced landing, additional conditions (e.g. ceiling) must be specified.

(b) The pilot- in-command may not commence take-off unless the weather

conditions at the aerodrome of departure are equal to or better than applicable minima for landing at that aerodrome unless a suitable take-off alternate aerodrome is available.

(c) When the reported meteorological visibility is below that required for take-off

and RVR is not reported, a take-off may only be commenced if the pilot- in-command can determine that the RVR / visibility along the take-off runway is equal to or better than the required minimum.

(d) When no reported meteorological visibility or RVR is available, a take-off

may only be commenced if the pilot- in-command can determine that the RVR / visibility along the take-off runway is equal to or better than the required minimum.

(2) Visual reference The take-off minima must be selected to ensure sufficient guidance to control the aeroplane in the event of both a discontinued take-off in adverse circumstances and a continued take-off after failure of the critical power unit. (3) Required RVR / Visibility

(a) For multi-engined aeroplanes, whose performance is such that, in the event of a critical power unit failure at any point during take-off, the aeroplane can either stop or continue the take-off to a height of 1 500 feet above the aerodrome while clearing obstacles by the required margins, the take-off minima established by an operator must be expressed as RVR / Visibility values not lower than those given in Table 1 below except as provided in paragraph (4) below:

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Table 1: RVR / Visibility for take-off

Take-off RVR / Visibility

Facilities RVR / Visibility (Note 3) Nil (day only) 500 m Runway edge lighting and/or cenreline marking 250/300 m (note 1 and 2) Runway edge and centreline lighting 200/250 m (Note 1) Runway edge and centreline lighting and multiple RVR information

150/200 m (Note 1 and 4)

Notes: 1. The higher values apply to Category D aeroplanes. 2. For night operations at least runway edge and runway end lights are required. 3. The reported RVR / Visibility value representative of the initial part of the take-off run can be replaced by pilot assessment. 4. The required RVR value must be achieved for all of the relevant RVR reporting points with the exception given in Note 3 above.

(b) For multi-engined aeroplanes whose performance is such that they cannot comply with the performance conditions in subparagraph (3)(a) above in the event of a critical power unit failure, there may be a need to reland immediately and to see and avoid obstacles in the take-off area. Such aeroplanes may be operated to the following take-off minima provided they are able to comply with the applicable obstacle clearance criteria, assuming engine failure at the height specified. The take-off minima established by an operator must be based upon the height from which the one engine inoperative net take-off flight path can be constructed. The RVR minima used may not be lower than either of the values given in Table 1 above or Table 2 below.

Table 2:

Assumed engine failure height above the runway versus RVR / Visibility

Take-off RVR / Visibility flight path Assumed engine failure height above

the take-off runway RVR / Visibility (Note 2)

< 50 ft 200 m 51 100 ft 300 m

101 150 ft 400 m 151 200 ft 500 m 201 300 ft 1 000 m

> 300 ft 1 500 m (Note 1)

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Notes: 1. 1 500 m is also applicable if no positive take-off flight path can be constructed. 2. The reported RVR / Visibility value representative of the initial part of the take- off run can be replaced by pilot assessment.

(c) When reported RVR, or meteorological visibility is not available, the pilot-in- command may not commence take-off unless he or she can determine that the actual conditions satisfy the applicable take-off minima.

QUESTIONS DEPARTURE AERODROME

May I convert visibility to RVR, or visa versa, to establish take-off minima? No. If the aerodrome of departure is equipped with RVR observation sights, RVR values will be given for take-off. It would be pointless converting these RVR values to visibility as a more restrictive value will be obtained. If the aerodrome of departure is not equipped with RVR observation sights, visibility values will be given for take-off. As per CATS 121.07.7.8.(1) / CATS 135.07.7.8.(1), meteorological visibility may not be converted to RVR for calculating take-off minima, however, as per CATS 121.07.7.1(1)(c) and (d) / CATS 135.07.7.1 (1)(c) and (d), if the reported meteorological visibility is below that required for take-off or no reported meteorological visibility is available and RVR IS NOT REPORTED, a take-off may be commenced if the pilot-in-command can determine that the RVR / visibility along the take-off runway is equal to or better than the required minimum. The RVR / visibility can be determined by lining up on the active runway and counting the number of runway edge light or centreline lights visible. Multiple the number of lights counted by the distance that the lights are spaced (obtained from the Aeronautical Information Publication, Jeppeson or Aerad) to determine the RVR / visibility.

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If touch-down RVR is not available, may I still depart? As per CATS 121.07.7.1(3)(a) / CATS 135.07.7.1 (3)(a), the reported RVR / Visibility value representative of the initial part of the take-off run can be replaced by pilot assessment. The RVR / Visibility of the initial part of the take-off run can be determined by counting the runway lights as described previously. If the RVR / visibility is equal to or better than the required minimum, the take-off may be continued. If the touch-down and mid-zone RVR readings are equal to or greater than the required minimum, but the roll-out RVR is below minimum, may I still depart? As per CATS 121.07.7.1(3)(a) / CATS 135.07.7.1 (3)(a), the required RVR value must be achieved for all of the relevant RVR reporting points with the exception given in question 2. If the runway is 3000 meters long and the calculated accelerate-stop distance / accelerate-go distance is less than 2000 meters, only the touch-down and mid-zone values must be at or above the required values. How do I calculate the assumed engine failure height? If your aircraft is unable to clear all obstacles by the required margins in the event of an engine failure, it is vital that you are able to see and avoid all the obstacles in your flight path. If your aircraft climbs a certain height with all its engines operating and then experiences an engine failure and is able to continue the climb clearing all the obstacles by the required margins, then you are only at risk until the aircraft reaches this certain height, because if you experience an engine failure above this certain height, you can safely continue the climb. You need to determine to what height you have to climb your aircraft with all its engines operating to then be able to clear all obstacles if an engine should fail. This height is known as the assumed engine failure height. Page 6

The higher the assumed engine failure height, the longer you will be at risk until you reaches this height. While you are below this height, should an engine fail the aircraft will not clear all the obstacles by the required margins so you will have to see the obstacles so that you can avoid them. The higher the assumed engine failure height, the greater the RVR / visibility required for take-off to ensure that should an engine failure occur below this height, you will be able to see and avoid all the obstacles. In order to calculate the assumed engine failure height, you need to plot your aircrafts multi-engine take-off flight path from your lift-off point down the runway. You then need to plot your aircrafts engine-out take-off flight path so that it clears the most restrictive obstacle in your flight path by the required margin. You must then calculate at what height above the runway these two plots intersect to determine the assumed engine failure height. You then enter Table 2 with this assumed engine failure height to determine the RVR / visibility required for take-off.

The assumed engine failure height is calculated to be 105 feet, therefore, using Table 2, the required RVR / visibility is 400 meters. Page 7

35 ft

105 ft

Multi-engine take-off flight path

Engine-out take-off flight path

LOW VISIBILITY PROCEDURES (LVPs)

Low visibility procedures become effective when Category II and III approaches are being flown to ensure that the Localiser Sensitive Area is protected against interference.

ENR 1.8.3 : Low visibility procedures (LVP's)

1.8.3.1 Introduction These procedures have been devised to simplify the differing requirements of Category II and III operations. To achieve this, during the relevant weather conditions (see 2 below), the localizer sensitive area (LSA) is to be safe guarded. This ensures the protection of the localizer signal against interference and at the same time effectively meets the obstacle free zone requirements. (OFZ)

1.8.3.2 General

ATC Low Visibility Procedures become effective when:

a. The lowest RVR is less than 600 metres. b. The cloud ceiling is 200 feet or less irrespective of the serviceability state of the ILS, lighting, standby power, etc.

Pilots can expect ILS localizer and glide path signals to be fully protected from interference during the final approach, from the time that pilots are notified that LVP's are in operation until the time that pilots are notified that LVP's have been cancelled.

ATC will inform pilots when LVP's are in force. This may be obtained via the ATIS.

1.8.3.3 Localizer Sensitive Area (LSA)

For practicable purposes, the LSA is a rectangular area contained within parallel lines 150 m either side of the runway centreline and between the localizer aerial and the beginning of the runway demarcated by the airport authority.

No person, vehicle or aircraft is to be permitted to infringe the LSA from the time when: a. An approaching aircraft is 10 NM from touchdown until it has vacated the

LSA. b. A departing aircraft has commenced it's take-off run until it is airborne,

and has passed the LLZ antenna.

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QUESTIONS LOW VISIBILITY PROCEDURES

Must LVPs be in force if the RVR / visibility is below 400 meters? According to the Joint Aviation Regulations (JAR-OPS), if a take-off is to be commenced when the RVR is less than 400 metres, Low Visibility Procedures (LVPs) must be in force. The Civil Aviation Regulations do not state this restriction under CATS 121.07.7 / CATS 135.07.7 (Take-off minima). Due to the fact that our Regulations are based on the Joint Aviation Regulations, it would be wise to adhere to this restriction. When do LVPs become effective? As per ENR 1.8.3, low visibility procedures become effective when the lowest RVR is less than 600 meters and / or the cloud ceiling is 200 feet or less.

TAKE-OFF ALTERNATE AERODROME The weather minima at the aerodrome of departure only takes into account the need to see the runway ahead of you to keep the aircraft straight down the runway in the event of an engine failure. It does not consider the fact of getting airborne after the engine failure and having to return. For this reason, if the weather at the aerodrome of departure precludes a return for landing, a take-off alternate is required. The weather minima required at the take-off alternate is normal landing minima one hour before to one hour after your ETA. Page 9

CAR 1.00.1 : Definitions Take-off alternate aerodrome means an aerodrome to which a flight may proceed should the weather conditions at the aerodrome of departure preclude a return for landing. CAR 91.07.7 : Pre-flight selection of aerodrome (3) The owner or operator shall select and specify in the air traffic service flight

plan referred to in Regulation 91.03.3, a take-off alternate aerodrome, if it would not be possible for the aircraft to return to the aerodrome of departure due to meteorological or performance reasons.

(4) The take-off alternate aerodrome referred to in sub-regulation (3), shall be located within -

(a) one hour flight time at one-engine cruising speed according to the aircraft flight manual referred to in Regulation 91.03.2 , in still air standard conditions based on the actual take-off mass for a twin-engine aircraft; (b) two hours flight time at one-engine inoperative cruising speed according to the aircraft flight manual referred to in Regulation 91.03.2, in still air standard conditions based on the actual take-off mass for three-engine and four-engine aircraft;

(c) if the aircraft flight manual referred to in Regulation 91.03.2, does not contain a one-engine inoperative cruising speed, the speed to be used for calculation, shall be the speed which is achieved with the remaining engine set at maximum continuous power.

CAR 91.07.8 : Planning minima for IFR flights

(1) The owner or operator of an aircraft shall not select an aerodrome as a take-off alternate aerodrome for a flight to be conducted, wholly or partly in accordance with IFR under IMC unless the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing one hour before and ending one hour after the estimated time of arrival at the aerodrome, the weather conditions will be at or above the applicable landing minima prescribed in Regulation 91.07.5.

(2) The ceiling shall be taken into account when the only approaches available are

non-precision or circling approaches.

(3) Any limitation related to one-engine inoperative operations shall be taken into account.

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QUESTIONS TAKE-OFF ALTERNATE If your twin-engine aircraft has a single-engine cruise speed of 100 knots and your take-off alternate aerodrome is 100 nautical miles away, may you depart if the forecast headwind to your take-off alternate is 50 knots? (Flying time to take-off alternate will be 1 hour 30 minutes.) Yes. As per CAR 91.07.7 (4), the take-off alternate aerodrome shall be located within one hour flight time at one-engine cruising speed according to the aircraft flight manual referred to in Regulation 91.03.2, in still air standard conditions based on the actual take-off mass for a twin-engine aircraft. You want to take-off from Lanseria International Airport with Johannesburg International Airport as your take-off alternate, Johannesburg International Airport is 30 minutes flying time away at your one-engine cruising speed in still air standard conditions, however, the forecast RVR at Johannesburg International Airport is below landing minima. You phone the weather bureau and they advice you that the fog is burning off and the RVR values are now above that required for landing, and state that the weather is improving. May you depart? No, you may only depart in 30 minutes. If you depart immediately and experience an engine failure, you will divert to your take-off alternate aerodrome and arrive there 30 minutes later. Although the weather at Johannesburg International Airport will be above landing minima, it would not have been above this minima for one hour before your arrival time. As per CAR 91.07.8, the owner or operator of an aircraft shall not select an aerodrome as a take-off alternate aerodrome for a flight to be conducted, wholly or partly in accordance with IFR under IMC unless the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing one hour before and ending one hour after the estimated time of arrival at the aerodrome, the weather conditions will be at or above the applicable landing minima prescribed in Regulation 91.07.5. Page 11

Can your aerodrome of departure be your take-off alternate aerodrome? No. By definition a take-off alternate aerodrome is an aerodrome to which a flight may proceed should the weather conditions at the aerodrome of departure preclude a return for landing. If you are able to land back at your aerodrome of departure, no take-off alternate aerodrome is required and therefore you do have to stipulate a take-off alternate on your flight plan .

DESTINATION AERODROME

Once you have established that you can get legally and safely take-off from the aerodrome of departure, you need to check the status of all the facilities at the destination aerodrome to establish the landing minima. The landing minima are then compared with the actual or forecast weather to establish whether the required minima are going to be achieved.

CAR 91.07.8 : Planning minima for IFR flights (4) The owner or operator of an aircraft shall only select the destination aerodrome or

destination alternate aerodrome when the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing one hour before and ending one hour after the estimated time of arrival at the aerodrome, the weather conditions will be at, or above, the applicable planning minima as follows:

(a) Planning minima for a destination aerodrome-

(i) RVR or visibility specified in accordance with Regulation 91.07.5; and (ii) for non-precision approach or a circling approach, the ceiling at, or above, MDA/H; and

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CATS 121.07.7.2 / CATS 135.07.7.2 : Aerodrome operating minima

Non-precision approach

(1) System minima (a) An operator must ensure that system minima for non-precision approach

procedures, which are based upon the use of ILS without glide path (LLZ only), VOR, NDB, SRA and VDF are not lower than the MDH values given in Table 3 below.

Table 3: System minima for non-precision approach aids

System minima

Facility Lowest MDH ILS (no glide-path LLZ) 250 ft VOR 300 ft VOR / DME 250 ft NDB 300 ft

(2) Minimum descent height An operator must ensure that the minimum descent height for a non- precision approach is not lower than either

(a) the OCH/OCL for the Category of aeroplane; or (b) the system minimum.

(3) Visual reference A pilot may not continue an approach below MDA / MDH unless at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:

(a) Elements of the approach light system; (b) the threshold; (c) the threshold markings; (d) the threshold lights; (e) the threshold identification lights; (f) the visual glide slope indicator; (g) the touchdown zone or touchdown zone markings; (h) the touchdown zone lights; (i) runway edge lights; or (j) other visual references accepted by the Commissioner.

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(4) Required RVR The lowest minima to be used by an operator for non-precision approaches are:

Table 4(a): RVR for non-precision approach full facilities

Non-precision approach minima Full facilities (Notes (1), (5), (6) and (7)

MDH RVR/Aeroplane category A B C D

250 ft 299 ft 800 m 800 m 800 m 1 200 m 300 ft 449 ft 900 m 1 000 m 1 000 m 1 400 m 450 ft 649 ft 1 000 m 1 200 m 1 200 m 1 600 m

650 ft and above 1 200 m 1 400 m 1 400 m 1 800m

Table 4(b): RVR for non-precision approach intermediate facilities

Non-precision approach minima Intermediate facilities (Notes (1), (5), (6) and (7)

MDH RVR/Aeroplane category A B C D

250 ft 299 ft 1 000 m 1 100 m 1 200 m 1 400 m 300 ft 449 ft 1 200 m 1 300 m 1 400 m 1 600 m 450 ft 649 ft 1 400 m 1 500 m 1 600 m 1 800 m

650 ft and above 1 500 m 1 500 m 1 800 m 2 000 m Table 4(c): RVR for non-precision approach basic facilities

Non-precision approach minima

Basic facilities (Notes (3), (5), (6) and (7) MDH RVR/Aeroplane category

A B C D 250 ft 299 ft 1 200 m 1 300 m 1 400 m 1 600 m 300 ft 449 ft 1 300 m 1 400 m 1 600 m 1 800 m 450 ft 649 ft 1 500 m 1 500 m 1 800 m 2 000 m

650 ft and above 1 500 m 1 500 m 2 000 m 2 000 m

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Table 4(d): RVR for non-precision approach Nil approach light facilities

Non-precision approach minima

Nil approach light facilities (Notes (4), (5), (6) and (7) MDH RVR/Aeroplane category

A B C D 250 ft 299 ft 1 500 m 1 500 m 1 600 m 1 800 m 300 ft 449 ft 1 500 m 1 500 m 1 800 m 2 000 m 450 ft 649 ft 1 500 m 1 500 m 2 000 m 2 000 m

650 ft and above 1 500 m 1 500 m 2 000 m 2 000 m Notes:

1. Full facilities comprise runway markings, 720 m or more of HI/MI approach lights, runway edge lights, threshold lights and runway end lights. Lights must be on.

2. Intermediate facilities comprise runway markings, 420 - 719 m of HI/MI approach lights, runway edge lights, threshold lights and runway end lights. Lights must be on.

3. Basic facilities comprise runway markings, < 420 m of HI/MI approach lights, any length of LI approach lights, runway edge lights, threshold lights and runway end lights. Lights must be on.

4. Nil approach light facilities comprise runway markings, runway edge lights, threshold lights, runway end lights or no lights at all.

5. The tables are only applicable to conventional approaches with a nominal descent slope of not greater than 4. Greater descent slopes will usually require that visual glide slope guidance (e.g. PAPI) is also visible at the Minimum Descent Height.

6. The above figures are either reported RVR or meteorological visibility converted to RVR as in TS 121.07.7.8 below.

7. The MDH mentioned in Table 4(a), 4 (b), 4(c) and 4(d) refers to the initial calculation of MDH. When selecting the associated RVR, there is no need to take account of a rounding up to the nearest ten feet, which may be done for operational purposes, e.g. conversion to MDA.

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Precision approach - Category I operations (1) General A Category I operation is a precision instrument approach procedure which provides for an approach to a decision height not lower than 200 ft and a visibility not less than 800 m or RVR not less than 550 m. (2) Decision height An operator must ensure that the decision height to be used for a Category I precision approach is not lower than -

(a) the minimum decision height specified in the aeroplane flight manual (AFM) if stated;

(b) the minimum height to which the precision approach aid can be used without the required visual reference; (c) the OCH/OCL for the category of aeroplane; or (d) 200 ft

(3) Visual reference A pilot may not continue an approach below the Category I decision height, determined in accordance with paragraph (2) above, unless at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:

(a) Elements of the approach light system; (b) the threshold; (c) the threshold markings; (d) the threshold lights; (e) the threshold identification lights; (f) the visual glide slope indicator; (g) the touchdown zone or touchdown zone markings; (h) the touchdown zone lights; or (i) runway edge lights.

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(4) Required RVR The lowest minima to be used by an operator for Category I operations are:

Table 5: RVR for Cat I approach vs facilities and DH

Category I minima DH Facilities/RVR (Note 5)

Full (Notes 1 & 6)

Intermediate (Notes 2 & 6)

Basic (Notes 3 & 6)

Nil (Notes 4 & 6)

200 ft 550 m 700 m 800 m 1 000 m 201 ft 250 ft 600 m 700 m 800 m 1 000 m 251 ft 300 ft 650 m 800 m 900 m 1 200 m

301 ft and above 800 m 900 m 1 000 m 1 200 m

Notes:

1. Full facilities comprise runway markings, 720 m or more of HI/MI approach lights, runway edge lights, threshold lights and runway end lights. Lights must be on.

2. Intermediate facilities comprise runway markings, 420 - 719 m of HI/MI approach lights, runway edge lights, threshold lights and runway end lights. Lights must be on.

3. Basic facilities comprise runway markings, < 420 m of HI/MI approach lights, any length of LI approach lights, runway edge lights, threshold lights and runway end lights. Lights must be on.

4. Nil approach light facilities comprise runway markings, runway edge lights, threshold lights, runway end lights or no lights at all.

5. The above figures are either the reported RVR or meteorological visibility converted to RVR as in accordance with technical standard 131.6.

6. The table is applicable to conventional approaches with a glide slope angle up to and including 4.

7. The DH mentioned in Table 5 refers to the initial calculation of DH. When selecting the associated RVR, there is no need to take account of a rounding up to the nearest ten feet, which may be done for operational purposes, e.g. conversion to DA.

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QUESTIONS DESTINATION AERODROME

A requirement to be satisfied before descending below DA/DH on an instrument approach is to have at least one of the required visual references in sight. One of these visual references is the visual glide slope indicator (PAPI or VASI). On reaching DA/DH you see the VASI. Will this VASI give you accurate glide path information until touchdown? No. A Visual Approach Slope Indicator (VASI) is only accurate to 200 feet. A Precision Approach Path Indicator (PAPI) is accurate until touchdown. What is the difference between MDA and DA? Minimum Descent Altitude (MDA) is a specified altitude in a non-precision approach below which descent may not be continued without the required visual reference. Depending on the rate-of-descent of the aircraft and groundspeed of the aircraft on the approach, the point where the aircraft reaches MDA will vary.

The red line depicts the ideal descent profile as the aircraft reaches MDA at the Visual Descent Point (VDP). If the required visual references are satisfied the aircraft can continue on this profile until touchdown. The black line depicts an aircraft that has descended fast or has encountered strong headwinds. The aircraft will have to level off at the MDA until the required visual references have been satisfied.

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Mapt VDPpd

MDA A

Sea Level

The blue line depicts an aircraft that has descended slow or has encountered strong tailwinds. If the required visual references are satisfied on reaching MDA, the aircraft will not be able to do a straight-in landing off the approach as it will be too high.

In all the above cases, if the required visual references are not satisfied, the aircraft will commence the go-around at or before missed approach point.

Decision altitude is a specified altitude in the precision approach at which a missed approach is initiated if the required visual references are not satisfied. If the ILS is flown accurately, the aircraft will always reach the DA at the same point. Due to the fact that the decision to land or go-around is made at the DA, the aircraft may descend through this altitude as the go-around is initiated.

THE ALTERNATE AERODROME

The last part of our planning phase is to consider our options if we are unable to land at our destination. It is not only the weather that could prevent us from landing at our destination, but unserviceable facilities, blocked runways or aircraft systems failures.

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DA

Glide slope intercept point

Sea Level

For this reason we need to select a destination alternate aerodrome(s). The weather at our selected destination alternate aerodrome(s) must have a safety factor built into it to ensure that if the weather were to deteriorate, our chances of landing at the destination alternate aerodrome would still be good. CATS 91.07.8, supplies a table to be used to determine the weather required at our destination alternate aerodrome(s)

CAR 91.07.8 Planning minima for IFR flights (4) The owner or operator of an aircraft shall only select the destination

aerodrome or destination alternate aerodrome when the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing one hour before and ending one hour after the estimated time of arrival at the aerodrome, the weather conditions will be at, or above, the applicable planning minima as follows:

(a) Planning minima for a destination aerodrome-

(i) RVR or visibility specified in accordance with Regulation

91.07.5; and (ii) for non-precision approach or a circling approach, the ceiling at, or above, MDA/MDH; and

(b) Planning minima for a destination alternate aerodrome shall be as prescribed in Document SA-CATS-OPS 91.

(5) The owner or operator of an aircraft shall not select an aerodrome as an en-

route alternate aerodrome unless the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing one hour before and ending one hour after the estimated time of arrival at the aerodrome, the weather conditions will be at or above the planning minima as prescribed in Document SA-CATS-OPS 91.

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CATS 91.07.8 Planning minima for IFR flights

(1) Planning minima for destination alternate aerodromes (1) An owner or operator may only select the destination aerodrome and / or

destination alternate aerodrome when the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing 1 hour before and ending 1 hour after the estimated time of arrival at the aerodrome, the weather conditions will be at or above the applicable planning minima as follows:

(b) Planning minima for the destination alternate aerodrome must be in

Accordance with Table 1.

Table 1: Planning minima En route and destination alternates

Type of approach Planning minima Cat II and III Cat I minima with RVR in accordance with TS 121.07.7 Cat I Non-precision minima and ceiling must be above MDH Non-precision Non-precision minima plus 200 ft added to MDH and

1 000 m added to RVR / Visibility. Ceiling must be above the MDH + 200 ft.

Circling Circling

2. Planning minima for en route alternate aerodromes (Non- ETOPS Flights)

An owner or operator may not select an aerodrome as an en route alternate aerodrome unless the appropriate weather reports or forecasts, or any combination thereof, indicate that, during a period commencing 1 hour before and ending 1 hour after the expected time of arrival at the aerodrome, the weather conditions will be at or above the planning minima prescribed in Table 1 above.

CAR 91.07.7 Pre-flight selection of aerodromes

(1) The owner or operator of an aircraft shall select destination or alternate aerodromes in accordance with Regulation 91.07.5 and Part 121, Part 127 or Part 135, as the case may be, when planning a flight.

(2) The owner or operator shall select a departure, destination or alternate

aerodrome only when the serviceability status of the aerodrome permits safe operation of the type of aircraft concerned.

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(6) The owner or operator of an aeroplane shall select at least one destination alternate aerodrome for each IFR flight, unless-

(a) two suitable non-intersecting runways are available at the destination aerodrome; and

(b) the meteorological conditions prevailing are such that, for the periods from one hour before until one hour after the expected time of arrival at the

destination aerodrome, the approach from the minimum sector safe altitude and landing can be made in VMC; or (c) the destination aerodrome is isolated and no adequate destination alternate aerodrome exists.

(7) The owner or operator shall select two destination alternate aerodromes when-

(a) the appropriate weather reports or forecasts for the destination aerodrome, or any combination thereof, indicate that during a period commencing one hour before and ending one hour after the estimated time of arrival, the weather conditions will be below the applicable planning minima; or

(b) no meteorological information can be obtained. (8) The owner or operator shall specify the destination alternate aerodrome in the air traffic service flight plan referred to in Regulation 91.03.3. (10) When planning a flight, the owner or operator shall only select an aerodrome as a destination or alternate aerodrome, if the appropriate weather reports or forecasts, or a combination thereof, are at or above the applicable planning minima for a period of one hour before to one hour after the estimated time of arrival of the aircraft at the aerodrome.

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QUESTIONS DESTINATION ALTERNATE AERODROMES

If you are unable to obtain the weather at your destination, or the weather at your destination is below minima, may you still depart? Yes, provided that you have two destination alternate aerodromes. As per CAR 91.07.7, the owner or operator shall select two destination alternate aerodromes when the appropriate weather reports or forecasts for the destination aerodrome, or any combination thereof, indicate that during a period commencing one hour before and ending one hour after the estimated time of arrival, the weather conditions will be below the applicable planning minima; or no meteorological information can be obtained. The weather must be above alternate weather minima at both these alternate aerodromes. When is a destination alternate aerodrome not required? As per CAR 91.07.7, a destination alternate aerodrome is not required for each IFR flight if two suitable non-intersecting runways are available at the destination aerodrome and the meteorological conditions prevailing are such that, for the periods from one hour before until one hour after the expected time of arrival at the destination aerodrome, the approach from the minimum sector safe altitude and landing can be made in VMC; or the destination aerodrome is isolated and no adequate destination alternate aerodrome exists.

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If you require two destination alternate aerodromes, do you require sufficient fuel to fly to the first alternate aerodrome and then to the second alternate aerodrome? No. You only have to carry sufficient fuel to fly to the most fuel critical destination alternate aerodrome. Before you commence the approach at your destination aerodrome you must obtain an update of the weather at your two destination alternate aerodromes and confirm the serviceability of these aerodromes and then decide which aerodrome you are going to nominate as you destination alternate aerodrome.

THE APPROACH BAN The approach ban stipulates that the pilot-in-command of an aircraft may commence an instrument approach regardless of the reported RVR / Visibility but the approach shall not be continued beyond the outer marker, or equivalent position, if the reported RVR / Visibility is less than the applicable minima. One of the reasons for enforcing an approach ban is so that departing traffic is not delayed while an aircraft attempts an approach with very little chance of success.

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ENR 1.8.2.6 Commencement and continuation of an approach. The pilot- in-command may commence an instrument approach regardless of the reported RVR / Visibility but the approach shall not be continued beyond the outer marker, or equivalent position, if the reported RVR / Visibility is less than the applicable minima (See CAR 91.07.25(1)).

(a) Where RVR is not available, RVR values may be derived by converting the reported visibility in accordance with table 9 below (conversion of visibility to RVR).

(b) If, after passing the outer marker or equivalent position in accordance with (a) above, the reported RVR / Visibility falls below the required minima, the pilot in command may continue the approach to DA/H or MDA/H. (c) Where no outer marker or equivalent position exist, the pilot in command shall decide whether to continue or abandon the approach before descending below 1 000 feet above the aerodrome on the final approach segment. (d) The approach may be continued below DA/H or MDA/H and the landing may be completed provided that the required visual reference is established at the DA/H or MDA/H and is maintained.

No aircraft shall descend below the state published OCA/H unless the required visual reference has been established.

QUESTIONS THE APPROACH BAN

If the ATIS states that the RVR at your destination aerodrome is below that required for the landing, may you still attempt the approach? Yes. As per ENR 1.8.2.6, you may commence the approach but you may not continue beyond the outer marker or descend below 1000 feet, as the case may be, if the RVR is still below that required for landing. Although you may try the approach, this is bad airmanship as you are wasting valuable fuel that you could rather use at your alternate aerodrome and you will hold up departing traffic while you attempt this approach. Page 25

After crossing the outer marker or equivalent point, ATC informs you that the RVR has reduced below that required for landing. May you continue the approach and land?

As per ENR 1.8.2.6, you may continue the approach, but you may only land if the required visual reference is established at or before DA/MDA.

TOOLS TO ASSIST THE PILOTS

As flying in poor weather conditions is stressful and demanding, the more tools the pilot has at his disposal, the safer the operation. The monitored approach The concept of the monitored approach is to let the co-pilot fly the approach, preferably with the help of an autopilot, while the captain monitors the flying. As the aircraft approaches the DA, the captain looks outside the aircraft to allow his / her eyes to focus long distance to improve the chances of obtaining the required visual clues, while the co-pilot keeps his / her eyes on the aircrafts instrumentation to maintain the correct flight profile. When reaching the DA the co-pilot will call-out DECIDE. If the captain has the required visual clues in sight, he / she will respond with LANDING and take control of the aircraft and land. If the captain does not have the required visual clues or elects to go-around, he will respond with GO-AROUND. The co-pilot will initiate the go-around and the captain will then assist as necessary. The same principle can be used for a non-precision approach. Page 26

The approach preparations

CHECK THE FOLLOWING

Weather at destination Is the weather above landing minima

Weather at alternate Is the weather above alternate landing minima

Crew qualifications Have the crew done two approaches in the last three months

Aircraft serviceability status Is the instrumentation serviceable. See MEL if required

Airfield serviceability status Are all the facilities and navigational aids serviceable

REVIEW INSTRUMENT APPROACH BRIEFING

Safety altitudes for the descent Pattern entry, instrument approach, go-around and missed approach Failures on final approach and go-around Standard call-outs Nominate alternate airfield Minimum fuel required for diversion and alternate course of action DISCUSS THE FOLLOWING Auto pilot annunciations Approach lighting system Use of anti-ice / de-ice, wipers, landing lights and autobrakes Handover point / Monitored approach

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APPROACH PREPARATIONS Review wind / general limitations Inform Air Traffic Control of approach intentions Review the approach ban Review the use of the auto pilot Review the taxi planning after landing Seat position APPROACH CALL-OUTS 500 feet in the slot----------------------------- Captain My calls------------------------------------------- Co-pilot 100 feet to minima----------------------------- Co-pilot Decide---------------------------------------------Co-pilot Landing or Go-around-------------------------Captain Page 28