What happened
On February 2, 2008, a Cirrus SR22, registration N824BJ, crashed near Lindsay Municipal Airport (1K2) in Lindsay, Oklahoma. The flight was being conducted as an instructional flight for a biennial flight review under Visual Meteorological Conditions (VMC).
At approximately 16:59, radar data showed the aircraft at 1,700 feet MSL, tracking north. The aircraft performed several maneuvers, including a 360-degree turn at 2,800 feet MSL, before tracking southeast toward the airport. By 17:12, the aircraft was approximately three-quarters of a mile northeast of the approach end of Runway 19, descending at 1,500 feet MSL.
Witnesses reported hearing the engine accelerate and then a loud boom. One witness observed the airplane falling at a 45-degree angle and disappearing behind trees before a ball of smoke appeared. Other witnesses reported hearing the engine "missing" or "cutting out" during the flight.
The aircraft struck the ground in a pasture approximately 0.25 miles northwest of the airport. The impact resulted in 2 fatal injuries, as both the flight instructor and the private pilot died from multiple blunt force injuries.
The investigation
An examination of the engine revealed no mechanical deficiencies that would have prevented normal operation. The fuel mixture control was in the full rich position, and the fuel pump was intact. The aircraft was within its allowable weight and balance envelope.
Data from the onboard Avidyne electronic flight displays provided a detailed reconstruction of the final seconds. At 17:12:47, the aircraft entered a right bank. By 17:13:05, the aircraft rolled into a steep left bank. During this maneuver, the angle of attack increased to 15 degrees. At 17:13:08, the bank angle reached 60 degrees and the angle of attack exceeded 17 degrees, which is consistent with a wings-level stall.
Analysis indicated that the left wing stalled before the right wing, creating additional yawing and rolling moments to the left. This was followed by a sudden reversal where the aircraft rolled and yawed violently to the right, similar to a snap-roll maneuver. The investigation suggested that the pilots may have applied large right rudder and aileron inputs in an attempt to recover, which instead initiated the snap roll. The aircraft was inverted and lacked sufficient altitude to recover before impacting the terrain.