NTSB Identification: LAX08LA027
14 CFR Part 91: General Aviation
Accident occurred Thursday, November 08, 2007 in Jean, NV
Probable Cause Approval Date: 12/24/2008
Aircraft: BEECH A36, registration: N3627B
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 airplane lost engine power while in cruise flight on a dark night. The pilot had been in contact with the local area Terminal Radar Approach Control (TRACON) facility and reported the situation to the controller. The pilot indicated that he was in-between airports and did not want to risk a turn back to the departure airport due to the dark night and mountainous terrain conditions. After reporting the power loss, the pilot lost radio contact with the controller and decided to attempt a landing on the desert floor. The pilot landed the airplane gear up and struck desert shrubbery, which caused structural damage to the airplane. The pilot stated that the engine sounded as if it had lost a cylinder or a valve and it was running "weakly." A review of the airplane’s logbooks revealed that the airplane had flown 14 hours since the last 100-hour/annual inspections. The factory-remanufactured engine had been installed on June 15, 2001, and had a total time of 717 hours. An engine teardown was performed and investigators noted that several camshaft gear teeth were missing, some of which were found in the oil sump. A metallurgical examination of the camshaft gear and teeth revealed signatures consistent with normal wear. Many of the surfaces on the camshaft gear had been damaged due to continued operation after the teeth separation. A fracture surface at the site of a missing tooth showed evidence of fatigue initiating at the surface. The metallurgist noted surface marks at the root on both sides of each tooth. Hardness was tested between the gear teeth on both parts and was found to meet component specifications based on the R30N scale.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The loss of engine power as a result of a fatigue failure of the camshaft gear teeth. Contributing to the accident were the dark night lighting conditions and the rough, uneven terrain the airplane encountered during the forced landing. Full narrative available
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