BOCA RATON, FL, USA
N9781B
CESSNA 172RG
The aircraft's engine lost partial power during climb after takeoff. The aircraft would not maintain altitude and a forced landing was made in a wooded area. Postcrash examination of the engine indicated the No. 4 exhaust valve had stuck and the exhaust valve pushrod was bent. No other engine malfunctions were noted. Textron Lycoming Engines issued mandatory service bulletin 388B on May 13, 1992, requiring the testing of the exhaust valve clearances each 400 flight hours on aircraft. The logbook records for N9781B did not have any entries showing compliance with service bulletin 388B.
On March 26, 1994, about 1215 eastern standard time, a Cesnna 172RG, N9781B, registered to ATE of Florida, Inc., landed in a wooded area following partial loss of engine power shortly after takeoff from Boca Raton Airport, Boca Raton, Florida, while on a 14 CFR Part 91 instructional flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft received substantial damage and the commercial-rated flight instructor and private-rated dual student were not injured. The flight originated at Fort Lauderdale, Florida, on March 26, 1994, about 1120. The flight instructor stated that the aircraft's engine lost partial power during climb after takeoff. They were unable to maintain altitude and a forced landing was made in a wooded area. After the accident maintenance personnel from the operator and a FAA inspector found the exhaust valve in the No. 4 cylinder had stuck and the push rod was bent. No other malfunctions in the engine were noted. Textron Lycoming Engines issued mandatory service bulletin 388B on May 13, 1992. This bulletin outlined a "procedure to determine exhaust valve and guide condition" and is "to insure positive and trouble free valve train operation." This bulletin required compliance each 400 hours of engine operation. Logbook records indicated the engine had accumulated 1,030 hours of operation since major overhaul and no entries to indicate service bulletin 388B had been complied with.
The failure of the aircraft operator to comply with engine manufacturers service bulletins which resulted in improper inspection of exhaust valves and subsequent sticking of the no. 4 exhaust valve.
Source: NTSB Aviation Accident Database
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