Witness and Pilot Accounts
Several witnesses who observed the taxi, runup, and takeoff reported that the engine was backfiring and that there was a snapping sound from the exhaust pipe during the runup. In a written statement, the pilot reported that the engine was backfiring during the engine start and taxi. The pilot asked the mechanic, who was also a passenger in the airplane, "Is that a problem?" The mechanic responded that it was not a problem because they had just completed the engine run.
Takeoff Sequence
The airplane appeared to have normal acceleration during the takeoff run. Immediately after rotation, the pilot noted that the airplane was not accelerating. After clearing a second line of trees, the pilot put the nose down briefly trying to gain some airspeed, but the aircraft continued to lose airspeed and altitude. The aircraft's left wing then hit a tree.
Engine Examination
Examination of the engine revealed that all twelve spark plugs were severely worn and fouled with lead and carbon deposits. The right magneto was moderately fouled with oil and had carbon tracks in the distributor. Aircraft log books indicated that the annual inspection was completed on the day of the accident.