AWO.B.CATIII.118 CS AWO.B.CATIII.118 Landing distance

This AMC applies when using HUDs in manual CAT III operations. A relevant feature of the HUD system to consider would be flare guidance.

Relevant procedural elements associated with using the HUD would be any specific aeroplane configuration, approach speed increment, thrust management or automatic throttle / thrust speed target.

The increment of the landing distance referred to in CS AWO.B.CATIII.118 when using a HUD may be derived as follows:

- (a) The configuration, procedure and speed should be those recommended in the associated procedures. - (b) The distance from the runway threshold to the touchdown point should be the distance from the runway threshold to the glideslope origin (SO) plus the mean distance from the glideslope origin to touchdown (STD) plus three times the standard deviation of the distance from the glideslope origin to touchdown (σSTD). - (c) The gross distance from touchdown to come to a complete stop should be determined in accordance with CS 25.125(b)(1) through (5), assuming a touchdown speed equal to the main touchdown speed plus three standard deviations of the touchdown speed.

Note: The main values and standard deviations considered in paragraphs (b) and (c) should be based on random variations as determined by AMC AWO.A.HUD.107. The systematic variation of parameters should cover the normal range of AFM conditions.

Easy Access Rules for All-Weather Operations (CS-AWO)

SECTION 4 -AIRWORTHINESS CERTIFICATION OF AEROPLANES FOR OPERATIONS WITH DECISION HEIGHTS (DHs) BELOW 30 M (100 FT) OR NO DECISION HEIGHT (DH) -CATEGORY III (CAT III) OPERATIONS

- (d) The landing distance should be taken as the distance from the runway threshold to the touchdown point, as defined in (b), i.e. SO + STD + 3σ(STD ), plus the ground-roll distance defined in (c). - (e) The landing distance should include corrections for variations in glideslope angle and variations in glideslope height at the threshold. Alternatively, these effects may be included by the use of conservative assumptions in the basic presentation of data, with the applicable ranges stated in the AFM.

[Issue: CS-AWO/2]

CONTROLS, INDICATORS AND ALERTS