The purpose of the flight was to recover the airplane from a farm field. The pilot walked the field, which was oriented east/west and measured about 1,000 ft long by 500 ft wide. The southeast corner of the field was bisected by high-tension power lines oriented northeast/southwest. The pilot stated to witnesses that he intended to begin the takeoff roll to the west along the northern border of the field and arc the takeoff path left 90° to the south. Once airborne, the pilot planned to fly the airplane beneath the power lines before climbing to cruise altitude. Cell phone video of the accident and measurements of the field revealed that, about 300 ft after starting the takeoff roll, the airplane turned sharply left toward the power lines. About 100 ft later, the airplane pitched up sharply and banked steeply left as it lifted off the ground. The airplane reached near the apex of its climb about 50 ft above the ground in about a 60° left bank; shortly thereafter, the airplane collided with terrain. Throughout the takeoff roll, initial climb, and the flight to ground contact, the engine accelerated smoothly, and ran continuously at high power without interruption. A detailed examination of the air frame and engine revealed no pre-impact mechanical anomalies that would have precluded normal operation.
The airplane's original 100-horsepower engine had been replaced with a 150-horspower engine, which likely influenced the pilot's decision to attempt the takeoff. The circumstances of the accident, including the lack of mechanical anomalies and the airplane's steep nose-up, left banking attitude just before impact, are consistent with the airplane exceeding its critical angle of attack during the initial climb after takeoff, which resulted in an aerodynamic stall at an altitude too low for recovery. The pilot did not survive.
The National Transportation Safety Board determined the probable cause of this accident to be the pilot's exceedance of the airplane's critical angle of attack while performing a turning takeoff, which resulted in an aerodynamic stall and loss of control. Contributing to the accident was the pilot's decision to attempt the takeoff, which he believed required a steep turn at a low altitude to avoid power lines.
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