FAA Flight Instructor Airplane (FIA)Aircraft Systems and InstrumentsEasy
On a standard airspeed indicator, a pilot observes the needle in the yellow arc during a descent. What does this arc range represent?
- ANormal operating range for all flight conditions
- BRange in which flap extension is structurally approved
- CRange in which the airplane will stall in a power-off, level-flight configuration
- DCaution range to be flown only in smooth air
Show answer & explanationAnswer & explanation
Correct answer: D. Caution range to be flown only in smooth air
The yellow arc on the airspeed indicator is the caution range, indicating speeds that should be flown only in smooth air because turbulence at these speeds could cause structural damage.
Why the other options are wrong
- A. The green arc, not yellow, represents normal operating range.
- B. Flap operating range is the white arc.
- C. Stall speeds correspond to the low-speed ends of the arcs, not the yellow arc itself.
Airspeed Indicator Color Coding
Colored arcs on the airspeed indicator denote operating speed ranges: white (flap range), green (normal range), yellow (caution, smooth air only), and a red line (never-exceed speed, VNE).
- White arc: VS0 to VFE, flap operating range
- Green arc: VS1 to VNO, normal operating range
- Yellow arc: VNO to VNE, caution range, smooth air only
- Red line: VNE, never-exceed speed
Memory trick: White for flaps, Green for go, Yellow for careful, Red for never