What happened
During a cross-county business flight, the pilot and four passengers were preparing to land at their destination. While operating within the airport traffic pattern, air traffic control queried the pilot regarding the possibility of using a shorter runway. Initially, the pilot declined the shorter runway, leading to instructions to enter a holding pattern for sequencing. Shortly after, the pilot indicated that the shorter runway would be acceptable, and received instructions to perform a left 270-degree turn to join the traffic pattern.
As the pilot began the left bank turn, the angle of the bank increased significantly after several seconds. This maneuver transitioned into a steep, nose-down descent. The aircraft subsequently struck a parking lot at a shopping center, located approximately 1.6 miles from the destination airport. The accident resulted in 5 fatalities.
Findings
An analysis of the flight data from the aircraft indicated that as the bank angle increased during the turn, the airspeed dropped to approximately 59 knots. This speed was significantly lower than the manufacturer's specified stall speed for any aircraft configuration. An inspection of the engines and the airframe following the crash showed no mechanical failures or anomalies that would have prevented the aircraft from operating normally. The investigation concluded that the pilot failed to maintain sufficient airspeed during the turn, causing the aircraft to exceed its critical angle of attack and enter an aerodynamic stall.