A gear warning horn will sound if the throttles are ______ and ______ of the landing gear are in the up position.

• A. Idle, any
• B. Retarded, any
• C. Retarded, all
• D. Full forward, any

Answer: (B)

The gear warning horn is a safety reminder that prevents landing with the gear up. It sounds when two conditions align: the airplane is being configured for landing, indicated by the throttles being moved toward the approach/idle range (retarded), and at least one landing gear is not in the down and locked position. If any gear remains up, the system will warn so the crew can extend the gear. If all gears are down and locked, the horn stays silent, since you’re in a safe landing configuration.

So the best match is throttles retarded and any gear up, because it covers the common approach scenario: reduced power signaling descent with the possibility of gear not being fully extended. The other options don’t fit the typical warning pattern: if throttles are full forward, the aircraft isn’t in a landing-approach state; if the requirement were all gears up, partial gear up wouldn’t trigger the horn; if throttles are idle, some systems wouldn’t reliably indicate approach readiness.