What is the HUD field of view?

• A. 30 degrees
• B. 20 degrees, with optical center four degrees below aircraft waterline.
• C. 15 degrees
• D. 45 degrees

Answer: (B)

The field of view of the HUD is the angular width of the display area that the pilot can see without moving the head. For this system, about 20 degrees is used, which strikes a balance between giving enough room to view flight symbology and horizon cues while still keeping most of the outside world in the pilot’s forward view. The optical center being placed roughly four degrees below the aircraft waterline is a deliberate alignment to match the pilot’s natural line of sight with the HUD image given the cockpit geometry and seating position. This offset helps ensure that in level flight the horizon and symbols appear in the expected places, reducing the need to tilt the head or eyes and improving readability across typical eye positions. If the field were much wider, the HUD could crowd the pilot’s view; if it were much narrower, important cues might be missed in peripheral vision.