FAA Aviation Mechanic Airframe (AMA)Airframe Electrical and InstrumentsMedium
A technician is inspecting the airspeed indicator on a single-engine airplane equipped with flaps. Which color marking on the dial indicates the flap operating speed range?
- AYellow arc
- BWhite arc
- CGreen arc
- DRed radial line
Show answer & explanationAnswer & explanation
Correct answer: B. White arc
The white arc on an airspeed indicator represents the flap operating range, extending from the power-off stalling speed with flaps and gear in landing configuration (Vso) to the maximum flap extended speed (Vfe).
Why the other options are wrong
- A. The yellow arc is the caution range, to be flown only in smooth air.
- C. The green arc represents the normal operating range, from Vs1 to Vno.
- D. The red radial line marks Vne, the never-exceed speed, not flap operation.
Airspeed Indicator Color Markings
Standardized colored arcs and lines on an airspeed indicator denote specific operating speed ranges and limits for safe aircraft operation.
- White arc = flap operating range (Vso to Vfe)
- Green arc = normal operating range (Vs1 to Vno)
- Yellow arc = caution range; red line = Vne (never exceed)
Memory trick: White for wings with flaps down.