Accident Cessna 182P N8158M, Friday 9 January 1998
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Date:Friday 9 January 1998
Time:18:56 LT
Type:Silhouette image of generic C182 model; specific model in this crash may look slightly different    
Cessna 182P
Owner/operator:Richard H. Graff
Registration: N8158M
MSN: 18264550
Year of manufacture:1976
Engine model:Continental O-470-S
Fatalities:Fatalities: 1 / Occupants: 1
Other fatalities:0
Aircraft damage: Destroyed
Location:Salinas, CA -   United States of America
Phase: En route
Departure airport:San Carlos, CA (KSQL)
Destination airport:Soledad, CA
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
During a night-time flight in marginal VFR conditions, the pilot radioed approach control that his aircraft's engine had begun running rough, losing power, and he was having difficulty maintaining altitude. Approach control vectored the pilot 14 miles back to the airport where he had previously completed an instrument approach. The pilot reported the runway in sight, however, the aircraft crashed on final approach 2 miles from the runway. A witness reported hearing the aircraft's engine as it approached, followed by 5 seconds of silence, and then the sound of impact. An annual inspection was completed on the aircraft about 2 weeks before the accident and this was believed to be the owner's first flight after the inspection. During the inspection, the Nos. 1, 3, and 4 cylinders were removed from the engine and repaired. Postaccident examination of the engine revealed that one of the two valve keepers had not been reinstalled on the No. 3 cylinder exhaust valve resulting in asymmetric loading of the remaining keeper. When that keeper fractured, the exhaust valve was released and entered the combustion chamber of the No. 3 cylinder where it contacted the piston. The consequential damage fractured the Nos. 3 and 4 pistons, the Nos. 3 and 4 connecting rods, and the crankcase.

Probable Cause: A loss of engine power due to a missing valve keeper. Also causal was the failure by engine maintenance personnel during engine top overhaul to install the second valve keeper in the No. 3 cylinder exhaust valve and the failure of inspection personnel to detect the improper assembly.

Accident investigation:
Investigating agency: NTSB
Report number: LAX98FA068
Status: Investigation completed
Duration: 2 years and 2 months
Download report: Final report




Revision history:

24-Oct-2008 10:30 ASN archive Added
21-Dec-2016 19:24 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
07-Apr-2024 15:03 ASN Update Bot Updated [Time, Aircraft type, Operator, Other fatalities, Departure airport, Source, Narrative, Category, Accident report]

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