AWO.A.HUD.113 CS AWO.A.HUD.113 Flare cue performance

- (a) The use of the flare cue during specific operations (e.g. steep approach, if approved) and abnormal conditions should be evaluated unless the AFM prohibits the use of the flare cue during those operations and/or abnormal conditions. The AFM should explicitly state whether there are cases when the flare cue cannot be used. - (b) Acceptable performance using a flare cue is achieved when the following criteria are demonstrated by flight test: - (1) touchdown is achieved within the touchdown zone, which is the first one third, or the first 3 000 ft, of the usable runway, whichever is more restrictive; - (2) the average touchdown sink rate does not exceed 6 ft per second;

- (3) touchdown with a bank angle that it is not hazardous to the aeroplane (i.e. no contact of any part of the engine nacelle or the wing with the ground).

A safe go-around is possible at any time including touchdown in all configurations to be certified.

- (c) The flare, from initiation until touchdown, should be assessed to ensure the following: - (1) Suitable flare performance that ensures the following: - (i) no evidence of early or late flare; - (ii) no over-flare or under-flare; - (iii) no undue 'pitch -down' tendency at flare initiation or during the flare; - (iv) no flare oscillation; - (v) no abrupt flare; - (vi) no inappropriate pitch response during the flare; - (vii) no unacceptable floating tendency; - (viii) any other unacceptable characteristic that a pilot could interpret as failure or inappropriate response of the flight guidance system, and disconnect, disregard, or contradict the flare indication. - (2) For a nominal range of 2.5 to 3.5° approach paths, demonstrate that there is not a substantial reduction in the flare performance from 2.0 to 4.0°.

[Issue: CS-AWO/2]

- (a) In accordance with CS AWO.HUD.113, the use of a flare cue during landing should ensure that the landing performance is acceptable according to the criteria established in AMC1 AWO.A.HUD.113 for all normal conditions where it is intended to be certified, which should include at least the following: - (1) landing weight range and centre-of-gravity (CG) range; - (2) range of speed, including possible aircraft failure cases for which flare cue is still intended to be used; - (3) tailwind; - (4) crosswind; - (5) turbulence; - (6) sensor (e.g. radio altimeter, vertical speed) nominal accuracy; - (7) runway slope and runway slope changes in touchdown zone; - (8) final approach angle; - (9) irregular terrain before to runway threshold.

- (b) Appropriate limitations on the use of the flare cue in relation to the conditions that it can be used should be published in the AFM.

[Issue: CS-AWO/2]