NTSB Identification: LAX98LA036.
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Accident occurred Wednesday, November 12, 1997 in SAN DIEGO, CA
Probable Cause Approval Date: 01/28/2000
Aircraft: Cessna 172RG, registration: N9451D
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 pilot and his instructor visually checked that the landing gear was down. On the landing roll the aircraft started to vibrate, and then rotated to the left. The instructor pilot shut down the engine and the right landing gear collapsed. The main gear actuator piston for the left main landing gear was found broken. A determination as to when the actuator piston was broken could not be made due to the extent of the damage. An examination of the aircraft logbook revealed that the main landing gear actuator piston had accumulated 1,530.2 hours since installation. The aircraft was examined on-scene with no further anomalies noted. An examination found beach marks on the fracture surface characteristic of a fatigue crack growth. The examination revealed that the fracture outside of the fatigue region was the result of a single event overload and not due to the fatigue crack.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

Overload of the main gear actuator piston and the subsequent collapse of the landing gear.

Full narrative available

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