FAA Commercial Pilot Airplane (CAX)Aircraft SystemsMedium
In a typical retractable-gear airplane, the landing gear aural warning horn is designed to sound automatically under which condition?
- AWhenever the master switch is turned on before engine start
- BWhen cabin pressurization exceeds the maximum differential limit
- CWhen the propeller control is moved to the feather position
- DWhen the throttle is retarded to a low power setting and the gear is not down and locked
Show answer & explanationAnswer & explanation
Correct answer: D. When the throttle is retarded to a low power setting and the gear is not down and locked
The gear warning horn is typically wired to a switch on the throttle linkage so that reducing power below a threshold (as would occur during approach/landing) with the gear retracted triggers an aural warning to prevent a gear-up landing.
Why the other options are wrong
- A. Master switch activation alone does not indicate an unsafe gear condition.
- B. Cabin pressurization limits are unrelated to the gear warning system.
- C. Propeller feathering is unrelated to landing gear position warnings.
Landing Gear Warning Horn
An aural alert triggered when engine power is reduced to approach settings while the landing gear is not down and locked, warning of a possible gear-up landing.
- Linked to throttle position, not just gear switches
- Prevents inadvertent gear-up landings
- Distinct from the squat switch, which senses weight on wheels
Memory trick: Throttle back, gear up = horn's alarm cry.