What happened
During a moose telemetry flight conducted at altitudes between 200 and 500 feet AGL, the aircraft impacted a marsh in a nearly vertical, nose-down attitude. The impact caused the engine and propeller to become buried in approximately three feet of mud and water. While the wings and tail cone remained attached to the fuselage in a vertical position, the leading edges of both the left and right wings sustained crushing along their entire spans, and the tail cone was buckled forward.
The investigation
Mechanical examination of the engine revealed no anomalies present prior to the impact. However, the propeller blades showed evidence of chordwise scratching and nicks along the leading edges. Investigators confirmed that flight control continuity was maintained from the cockpit to the flight controls.
Records indicate the aircraft had a total time of 7,067 hours. The pilot had approximately 167 flight hours in this specific airplane and had most recently demonstrated proficiency in stalls and slow flight during a Biennial Flight Review on April 25, 1999. It was also noted that the airplane's stall warning horn had been deactivated shortly after the aircraft was acquired in 1977.