LAKE DALLAS, TX, USA
N11064
CHAMPION 7ECA
THE PILOT PERFORMED AN ENGINE RUNUP BEFORE TAKEOFF ON RUNWAY 17. ACCORDING TO A WITNESS, THE AIRPLANE 'USED APPROXIMATELY 2,000 FEET OF RUNWAY TO BECOME AIRBORNE.' ANOTHER WITNESS OBSERVED THE AIRCRAFT'S DEPARTURE AND REPORTED THAT IT 'APPEARED TO BE UNDER POWERED AND SLOW.' ANOTHER WITNESS REPORTED THAT THE PLANE PASSED OVERHEAD AND 'I HEARD THE ENGINE SPUTTER.' HE FURTHER OBSERVED 'I SAW THE PLANE BANK UP AND TO THE EAST; THE ENGINE SPUTTERED TWICE AGAIN AND THE PLANE STALLED OUT SPIRALLING DOWN INTO THE WATER.' AN EXAMINATION OF THE ENGINE REVEALED THAT THE NUMBER ONE CYLINDER EXHAUST VALVE WAS STUCK IN THE OPEN POSITION DUE TO CARBON BUILDUP ON THE VALVE GUIDE.
HISTORY OF FLIGHT On July 5, 1995, at 1558 central daylight time, a Champion 7ECA, N11064, was destroyed while maneuvering near Lake Dallas, Texas. The private pilot was seriously injured and his passenger sustained minor injuries. The aircraft was being operated under Title 14 CFR Part 91. The flight originated from Lakeview Airport near Lake Dallas, Texas, at approximately 1557. Visual meteorological conditions prevailed for the local personal flight and a flight plan was not filed. According to a witness, the pilot performed an engine runup before takeoff from runway 17. Another witness observed the aircraft on departure and reported that it "appeared to be under powered and slow." Another witness reported that the plane passed overhead and "I heard the engine sputter." He further observed "I saw the plane bank up and to the east; the engine sputtered twice again and the plane stalled out spiralling down into the water." AIRCRAFT INFORMATION According to a witness, the airplane "used approximately 2,000 feet of runway to become airborne." Under standard conditions, it was calculated by the investigator-in-charge, this aircraft should be airborne in 450 feet. The calculated density altitude was 3,000 feet. This would give an adjusted calculated takeoff-roll of 787 feet. The airplane's maintenance log books were in aircraft at the time of the accident and were subsequently lost in the lake. The pilot/owner did report to the investigator-in-charge in a telephone interview that approximately a year before the accident, that the engine had experienced a "stuck" valve and he had a mechanic "stake" the valve to break it loss. No further maintenance was performed on the engine in regards to this valve problem. WRECKAGE AND IMPACT INFORMATION The airplane came to rest in Lewisville Lake approximately 15 feet from the shore of an island (part of Willow Grove Park), in 3 feet of water. The left wing had been separated from the aircraft and the fuselage had been broken in several places. Examination of the engine revealed that the exhaust valve for the number one cylinder was stuck in the open position. TESTS AND RESEARCH The cylinder was removed and sent to the engine manufactures factory for further evaluation (see enclosed Analytical Inspection Report). ADDITIONAL DATA The airplane was released to the owner.
THE PILOT'S FAILURE TO MAINTAIN AIRSPEED AND THE RESULTING INADVERTENT STALL/SPIN. A FACTOR WAS INADEQUATE MAINTENANCE RESULTING IN THE PARTIAL LOSS OF ENGINE POWER DUE TO THE NUMBER ONE CYLINDER EXHAUST VALVE BEING STUCK OPEN.
Source: NTSB Aviation Accident Database
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