What happened
During a scheduled cargo charter operation, the pilot encountered difficulties with the left engine shortly after departing the airport. The pilot notified air traffic control of the situation, expressing an intention to return to the airfield for an emergency landing. To facilitate this, the pilot initiated a left-hand traffic pattern.
Following the initial departure, GPS tracking indicated that the aircraft type (not specified in source) performed a left turn toward a southeasterly direction, reaching a peak altitude of approximately 959 feet. The flight path then transitioned into a subsequent left turn that continued until the aircraft's descent ended near the accident site, located roughly 0.50 miles southeast of the runway's displaced threshold.
Findings
Analysis of GPS data and environmental wind conditions indicated that the airspeed during the turning maneuver had dropped to approximately 45 knots. This speed was significantly lower than the 59-knot stall speed required for level flight with flaps extended, as specified in the airplane's flight manual. While the pilot had reported issues with the left engine, post-accident inspections of the airframe and engines found no mechanical failures that would have prevented standard operation, leaving the exact nature of the engine trouble unconfirmed.
Ultimately, the investigation concluded that the pilot failed to maintain sufficient airspeed during the turn, leading to an aerodynamic stall and subsequent spin.