How is the Indicated Airspeed Indicator displayed?

How is the Indicated Airspeed Indicator displayed?

• A. Green lighted for night vision goggle compatibility
• B. Red lighted for NVG incompatibility
• C. Blue indicator for daylight use
• D. No indicator

Answer: (A)

Night vision goggle (NVG) operations rely on cockpit lighting that stays easy on the eyes and readable through NVGs. The Indicated Airspeed Indicator uses a green illumination as the cue that it is NVG compatible. Green light is chosen because it is easier on the eyes and readable through NVGs without causing glare or losing contrast in low-light conditions. So when this indicator is green, it signals to the pilot that the IAS display is NVG-friendly. The other options don’t fit how NVG compatibility is conveyed: red would imply the opposite, blue for daylight use isn’t standard for this signal, and having no indicator wouldn’t provide the NVG compatibility cue.

Night vision goggle (NVG) operations rely on cockpit lighting that stays easy on the eyes and readable through NVGs. The Indicated Airspeed Indicator uses a green illumination as the cue that it is NVG compatible. Green light is chosen because it is easier on the eyes and readable through NVGs without causing glare or losing contrast in low-light conditions. So when this indicator is green, it signals to the pilot that the IAS display is NVG-friendly. The other options don’t fit how NVG compatibility is conveyed: red would imply the opposite, blue for daylight use isn’t standard for this signal, and having no indicator wouldn’t provide the NVG compatibility cue.