Witness Observations
Multiple witnesses reported observing the airplane flying at an estimated altitude of 500 feet. Two witnesses stated they heard the engine sound increase, and one witness reported hearing the engine 'restart.' The airplane subsequently descended in a 'loose spiral.' According to a witness, the nose came up, the airplane turned to the right, then 'sharply to the left...into a steep tight spiral.' The airplane then impacted the terrain going 'straight down.'
Radar Data Analysis
Evaluation of radar data revealed that the airplane slowed to an airspeed of 50 knots at an altitude of 2,500 feet mean sea level (MSL). The angle of attack increased to 8.59 degrees, and the airplane began a rapid descent. The last radar return placed the airplane at 1,500 feet MSL with a vertical velocity of approximately -9,000 feet per minute.
Wreckage Examination
Examination of the wreckage revealed symmetric crushing of the leading edges, corresponding to an impact angle of approximately 30 degrees nose down. No evidence of preimpact mechanical malfunction was found.