AWO.A.HUD.111 CS AWO.A.HUD.111 Head-up displays used for synthetic vision guidance systems

A HUD (or equivalent display) used in a synthetic vision guidance system (SVGS) shall:

- (a) provide a means to control the SVGS scene brightness that is independent of the HUD (or equivalent display) symbology brightness control; this control shall be operable without causing excessive pilot workload, distraction or fatigue; - (b) provide a readily accessible control to enable the pilot to remove and reactivate the SVGS image from the HUD (or equivalent display) without requiring the pilot to remove their hands from the primary flight controls and thrust control; - (c) not cause interference with the safe and effective use of the pilot compartment view, either internally or externally; - (d) not cause adverse physiological effects to the pilots, such as fatigue or eye strain; - (e) not significantly alter the colour perception of the external scene; - (f) allow the pilot to recognise misaligned or non-conformal conditions in a timely manner; and - (g) not create a combination of display features to the extent that display clutter reduces the efficiency of reading and interpreting the pilot's external visual cue s.

If found to be necessary, a means to control the SVGS scene contrast shall be provided.

Note: In point (f), the misalignment or non-conformal conditions shall be those that can be detected by the system.

[Issue: CS-AWO/2]

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