NTSB Identification: LAX98LA065.
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Accident occurred Tuesday, December 30, 1997 in VAN NUYS, CA
Probable Cause Approval Date: 05/04/1998
Aircraft: Cessna 172RG, registration: N5404V
Injuries: 2 Uninjured.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The flight instructor stated that the student pilot had extended the landing gear on the downwind leg of the traffic pattern, but then retracted it after being told to go around by the control tower. On the second downwind leg, the student again placed the gear switch in the down position; however, neither the student nor the instructor visually verified that the gear was down and locked. During the final flare for landing, the instructor noted that the gear was not down and that the 5 amp gear warning circuit breaker had opened. He then closed the circuit breaker and noted the gear starting to extend, but it had achieved only an intermediate position at the time of touchdown. The airplane subsequently settled on to the runway and incurred damage to the underside, the right wing, and the right horizontal stabilizer. A review of the Cessna 172RG Service Manual, Drawing No. 2471000, 'Wiring Diagram-Landing Gear System' indicated that 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.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The student and flight instructor's failure to verify that the landing gear was in the down position, and the design of the electrical system in which a single-point aircraft system malfunction (one open circuit breaker) disabled both the landing gear warning system and the main gear downlock switches. Full narrative available
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