Incident Overview
A flight instructor and a student pilot were conducting training in a Cessna 172RG. During the traffic pattern, the student pilot extended the landing gear on the downwind leg but retracted it after being instructed to go around by the control tower. On the second downwind leg, the student again placed the landing gear switch in the down position. However, neither the student nor the instructor visually confirmed that the gear was down and locked.
Landing and Damage
During the final flare for landing, the instructor noticed that the landing gear was not down and that the 5-amp gear warning circuit breaker had opened. He closed the circuit breaker and observed the gear beginning to extend, but it had achieved only an intermediate position at the time of touchdown. The airplane subsequently settled onto the runway, resulting in damage to the underside, the right wing, and the right horizontal stabilizer.
Technical Reference
A review of the Cessna 172RG Service Manual, Drawing No. 2471000, 'Wiring Diagram-Landing Gear System' indicated that the subject circuit breaker, in addition to providing power to the gear indicator lights and warning horn, also powers the main gear downlock switches and the stall warning horn.