Primary finding
Probable cause
A partial loss of takeoff power due to inadequate maintenance and inspection which failed to detect magneto and spark plug deficiencies. In addition, the pilot failed to abort the takeoff after two unsuccessful attempts to get airborne. Factors which contributed to the accident were: the high density altitude and the pilot's lack of piloting experience.
Investigator assessment
Analysis narrative
During takeoff, the airplane was heard to reduce power at mid-field, then full power was applied. It climbed to about 6 ft, settled back onto the rwy, climbed again to 6 ft, settled again, then continued its takeoff roll using most of the 5,850-ft rwy until reaching the arpt perimeter fence. It climbed to about 20 ft agl, then settled into a house. The density altitude was 7,800 ft. Engine examination revealed that the magneto-to-engine timing was off, the magneto internal timing was off on both sets of points, and both point gaps were off. In addition, 5 of the 12 spark plugs were found to have worn electrodes. One spark plug was not approved for the engine. A 100-hr inspection had been completed on 2/2/93, about 17 flight-hours before the accident.
Source record
Factual narrative
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