NTSB Identification: LAX99LA279.
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Accident occurred Saturday, August 21, 1999 in LIVERMORE, CA
Probable Cause Approval Date: 08/14/2001
Aircraft: Bellanca 7ECA, registration: N88408
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.
During the takeoff initial climb a partial loss of power was experienced, with the rpm's decreasing to 1,500 accompanied by roughness. The CFI took the controls from the student, made a 180-degree turn back to the runway, and landed hard on a taxiway. Both pilots indicated that there were no discrepancies noted with the preflight, engine start, taxi, or run-up. During the engine examination the number 3 exhaust valve was found broken, and the head found embedded in the piston. A review of the engine logbook revealed that the engine had accumulated 3,711.0 hours since the last major overhaul, which took place on November 30, 1993. According to the engine manufacturer, 2,400 hours or 12 calendar years is the maximum recommended time between overhaul. A Lycoming Mandatory Service Bulletin addresses the need to inspect exhaust valves and valve guides to prevent sticking and possible failure due to excessive guide wear. The bulletin recommends an inspection at 400-hour intervals. No record was found in the logbooks of compliance with the bulletin.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The failure of the no. 3 cylinder exhaust valve due to the operator's failure to adhere to recommended overhaul periods set by the engine manufacturer. A factor in the accident was the operator's failure to comply with the manufacturer's mandatory service bulletin. Full narrative available
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