19950715018499A

Crashed into creek. (-4)several witnesses who observed the taxi, runup, and takeoff, reported that the engine was backfiring and 'snapping' out of the exhaust pipe during the runup. In his written statement the pilot reported that the engine was backfiring during the engine start and taxi. He 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.' The airplane appeared to have 'normal' acceleration during the takeoff run. Immediately after rotation, he 'noted that the airplane was not accelerating...after clearing a second line of trees, I put the nose down briefly trying to gain some airspeed, but the aircraft continued to lose airspeed and altitude...the aircraft's left wing hit a tree.' Examination of the engine revealed 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 the annual inspection was completed on the day of the accident.