What should you verify about flap and trim indicators?

What should you verify about flap and trim indicators?

• A. Indicators show any random values.
• B. Indicators match a preflight log only.
• C. Position indicators match actual flap/trimmer position; check for sticking, abnormal noises, and proper retraction/extension.
• D. Indicators must be disabled during preflight.

Answer: (C)

The key idea is that flap and trim indicators must reflect the actual position of the flaps and stabilizer trim. You verify this by cycling the controls and watching the indicators while confirming the surfaces move to the commanded positions. The indicators should move smoothly and reach the exact position you select, with the physical surfaces agreeing with what the readout shows. This alignment is crucial because if the indicator and the actual position diverge, you won’t know the aircraft’s true configuration, which can affect lift, approach speeds, and stability during takeoff and landing. As you test, look for three things: that the indicators follow the control movements without sticking, that there are no abnormal noises suggesting binding or mechanical wear, and that the surfaces fully retract or extend to the commanded position. For the trim, ensure the indicator moves smoothly and the stabilizer actually moves to the indicated setting, with no hesitation or mismatch between the readout and the surface position. If you notice any misalignment, sticking, or odd noises, resolve it before flight to ensure predictable control feel and aircraft behavior.

The key idea is that flap and trim indicators must reflect the actual position of the flaps and stabilizer trim. You verify this by cycling the controls and watching the indicators while confirming the surfaces move to the commanded positions. The indicators should move smoothly and reach the exact position you select, with the physical surfaces agreeing with what the readout shows. This alignment is crucial because if the indicator and the actual position diverge, you won’t know the aircraft’s true configuration, which can affect lift, approach speeds, and stability during takeoff and landing.

As you test, look for three things: that the indicators follow the control movements without sticking, that there are no abnormal noises suggesting binding or mechanical wear, and that the surfaces fully retract or extend to the commanded position. For the trim, ensure the indicator moves smoothly and the stabilizer actually moves to the indicated setting, with no hesitation or mismatch between the readout and the surface position. If you notice any misalignment, sticking, or odd noises, resolve it before flight to ensure predictable control feel and aircraft behavior.