CAT.OP.MPA.115 Approach flight technique — aeroplanes

CONTINUOUS DESCENT FINAL APPROACH (CDFA) The following criteria apply to CDFA:

(a)For each NPA procedure to be used, the operator should provide information allowing the flight crew to determine the appropriate descent path. This information is either:

(1)a descent path depicted on the approach chart including check altitude/heights against range;

(2)a descent path coded into the aircraft flight management system; or

(3)a recommended descent rate based on estimated ground speed.

(b)The information provided to the crew should observe human factors principles.

(c)The descent path should be calculated to pass at or above the minimum altitude specified at any step-down fix.

(d)The optimum angle for the descent path is 3 and should not exceed 4,5 except for steep approach operations approved in accordance with this Part.

(e)For multi-pilot operations, the operator should establish procedures that require:

(1)the pilot monitoring to verbalise deviations from the required descent path;

(2)the pilot flying to make prompt corrections to deviation from the required descent path; and

(3)a call-out to be made when the aircraft is approaching the DA/H.

(f)A missed approach should be executed promptly at the DA/H or the MAPt, whichever is first, if the required visual references have not been established.

(g)For approaches other than circling approaches, the lateral part of the missed approach should be flown via the MAPt unless otherwise stated on the approach chart.

APPROACH OPERATIONS USING NPA PROCEDURES FLOWN WITH A FLIGHT TECHNIQUE OTHER THAN THE CDFA

(a)In case the CDFA technique is not used, the approach should be flown to an altitude/height at or above the MDA/H where a level flight segment at or above MDA/H may be flown to the MAPt.

(b)Even when the approach procedure is flown without the CDFA technique, the relevant procedures for ensuring a controlled and stable path to MDA/H should be followed.

(c)In case the CDFA technique is not used when flying an approach, the operator should implement procedures to ensure that early descent to the MDA/H will not result in a subsequent flight below MDA/H without adequate visual reference. These procedures could include:

(1)awareness of radio altimeter information with reference to the approach profile;

(2)terrain awareness warning system (TAWS);

(3)limitation of rate of descent;

(4)limitation of the number of repeated approaches;

(5)safeguards against too early descents with prolonged flight at MDA/H; and

(6)specification of visual requirements for the descent from the MDA/H.

(d)In case the CDFA technique is not used and when the MDA/H is high, it may be appropriate to make an early descent to MDA/H with appropriate safeguards such as the application of a significantly higher RVR or VIS.

(e)The procedures that are flown with level flight at or above the MDA/H should be listed in the OM.

(f)Operators should categorise aerodromes where there are approaches that require level flight at or above MDA/H as B or C. Such aerodrome categorisation will depend upon the operator’s experience, operational exposure, training programme(s) and flight crew qualification(s).

OPERATIONAL PROCEDURES AND INSTRUCTIONS AND TRAINING

(a)The operator should establish procedures and instructions for flying approaches using the CDFA technique and not using it. These procedures should be included in the operations manual and should include the duties of the flight crew during the conduct of such operations. The operator should ensure that the initial and recurrent flight crew training required by ORO.FC includes the use of the CDFA technique.

(b)Operators holding an approval to use another technique for NPAs on certain runways should establish procedures for the application of such techniques.

STABILISED APPROACH OPERATIONS — AEROPLANES The following criteria should be satisfied for all stabilised approach operations with aeroplanes:

(a)The flight management systems and approach aids should be correctly set, and any required radio aids identified before reaching a predetermined point or altitude/height on the approach.

(b)The aeroplane should be flown according to the following criteria from a predetermined point or altitude/height on the approach:

(1)the angle of bank should be less than 30 degrees; and

(2)the target rate of descent should be that required to maintain the correct vertical path at the planned approach speed.

(c)Variations in the rate of descent should normally not exceed 50 % of the target rate of descent.

(d)An aeroplane should be considered stabilised for landing when the following conditions are met:

(1)the aeroplane is tracking within an acceptable tolerance of the required lateral path;

(2)the aeroplane is tracking within an acceptable tolerance of the required vertical path;

(3)the vertical speed of the aeroplane is within an acceptable tolerance of the required rate of descent;

(4)the airspeed of the aeroplane is within an acceptable tolerance of the intended landing speed;

(5)the aeroplane is in the correct configuration for landing, unless operating procedures require a final configuration change for performance reasons after visual reference is acquired; and

(6)the thrust/power and trim settings are appropriate.

(e)The aeroplane should be stabilised for landing before reaching 500 ft above the landing runway threshold elevation.

(f)For approach operations where the pilot does not have visual reference with the ground, the aeroplane should additionally be stabilised for landing before reaching 1 000 ft above the landing runway threshold elevation except that a later stabilisation in airspeed may be acceptable if higher than normal approach speeds are required for operational reasons specified in the operations manual.

(g)The operator should specify the following in the operations manual:

(1)the acceptable tolerances referred to in (d);

(2)the means to identify the predetermined points referred to in (a) and (b). This should normally be the FAF.

(h)When the operator requests approval for an alternative to the stabilised approach criteria for a particular approach to a particular runway, the operator should demonstrate that the proposed alternative will ensure that an acceptable level of safety is achieved.

ACCEPTABLE TOLERANCES FOR STABILISED APPROACH OPERATIONS

(a)The requirement for the aircraft to be tracking within an acceptable tolerance of the required lateral path does not imply that the aircraft has to be aligned with the runway centre line by any particular height.

(b)The target rate of descent for the final approach segment (FAS) of a stabilised approach normally does not exceed 1 000 fpm. Where a rate of descent of more than 1 000 fpm will be required (e.g. due to high ground speed or a steeper-than-normal approach path), this should be briefed in advance.

(c)Operational reasons for specifying a higher-than-normal approach speed below 1 000 ft may include compliance with air traffic control (ATC) speed restrictions.

(d)For operations where a level flight segment is required during the approach (e.g. circling approaches or approaches flown as non-CDFA), the criteria in point (b) of AMC1 CAT.OP.MPA.115(a) should apply from the predetermined point until the start of the level flight segment and again from the point at which the aircraft begins descent from the level flight segment down to a point of 50 ft above the threshold or the point where the flare manoeuvre is initiated, if higher.

CONTINUOUS DESCENT FINAL APPROACH (CDFA)

(a)Introduction

(1)Controlled flight into terrain (CFIT) is a major hazard in aviation. Most CFIT accidents occur in the FAS of approach operations flown using the NPA procedures. The use of stabilised-approach criteria on a continuous descent with a constant, predetermined vertical path is seen as a major improvement in safety during the conduct of such approaches.

(2)The elimination of level flight segments at MDA close to the ground during approaches, and the avoidance of major changes in attitude and power/thrust close to the runway that can destabilise approaches, are seen as ways to reduce operational risks significantly.

(3)The term CDFA has been selected to cover a flight technique for instrument approach operations using NPA procedures.

(4)The advantages of CDFA are as follows:

(i)the technique enhances safe approach operations by the utilisation of standard operating practices;

(ii)the technique is similar to that used when flying an ILS approach, including when executing the missed approach and the associated missed approach procedure manoeuvre;

(iii)the aeroplane attitude may enable better acquisition of visual cues;

(iv)the technique may reduce pilot workload;

(v)the approach profile is fuel-efficient;

(vi)the approach profile affords reduced noise levels;

(vii)the technique affords procedural integration with 3D approach operations; and

(viii)when used and the approach is flown in a stabilised manner, CDFA is the safest approach technique for all instrument approach operations using NPA procedures.

(b)Stabilised approach (SAp)

(1)The control of the descent path is not the only consideration when using the CDFA technique. Control of the aeroplane’s configuration and energy is also vital to the safe conduct of an approach.

(2)The control of the flight path, described above as one of the specifications for conducting an SAp, should not be confused with the path specifications for using the CDFA technique. The predetermined path specification for conducting an SAp are established by the operator and published in the operations manual.

(3)The appropriate descent path for applying the CDFA technique is established by the following:

(A)the published ‘nominal’ slope information when the approach has a nominal vertical profile; and

(B)the designated final-approach segment minimum of 3 NM, and maximum, when using timing techniques, of 8 NM.

(4)Straight-in approach operations using CDFA do not have a level segment of flight at MDA/H. This enhances safety by mandating a prompt missed approach procedure manoeuvre at DA/H.

(5)An approach using the CDFA technique is always flown as an SAp, since this is a specification for applying CDFA. However, an SAp does not have to be flown using the CDFA technique, for example, a visual approach.

(c)Circling approach operations using the CDFA technique Circling approach operations using the CDFA technique require a continuous descent from an altitude/height at or above the FAF altitude/height until MDA/H or visual flight manoeuvre altitude/height. This does not preclude level flight at or above the MDA/H. This level flight may be at MDA/H while following the IAP or after visual reference has been established as the aircraft is aligned with the final approach track. The conditions for descent from level flight are described in AMC7 CAT.OP.MPA.110.