What happened
An air ambulance mission involving the pilot and two medical crew members began under night instrument meteorological conditions. Shortly after takeoff, air traffic control noted the aircraft was climbing through 4,400 feet MSL with an incorrect transponder code. After being instructed to correct the code, the aircraft leveled off briefly before resuming a steep climb at approximately 6,000 feet per minute toward 6,00 and 6,000 feet MSL. Following a frequency change and contact with departure control, the aircraft was radar-identified at 6,000 feet.
Approximately one minute later, the departure controller lost the aircraft's transponder signal. The pilot failed to respond to subsequent communications, and no further transmissions were recorded. Radar data indicated the aircraft entered a rapid descent, reaching speeds of 17,000 feet per minute. Surveillance footage from a nearby location captured the aircraft's lights descending at a 45-degree angle, followed by an explosion. The aircraft struck a pasture roughly 1.5 nautical miles south of the airport, resulting in a post-impact fire. All major components of the aircraft were found within the debris field. The wreckage and ground scarring indicated the aircraft struck the ground in a steep, nose-low, and wings-level attitude.
Findings
An analysis of the flight trajectory showed that while the aircraft reached a peak pitch of 23 degrees during the climb, the pitch subsequently decreased to an estimated -42 degrees at impact, while the roll angle increased to approximately -76 degrees. The investigation determined that the aircraft was capable of flying this trajectory without an aerodynamic stall. Data suggested that the pilot may have experienced a somatogravic illusion, where the physical sensations of acceleration during the climb created a false perception of level flight, leading to spatial disorientation.
Several contributing factors were identified, including the pilot's limited recent experience in night IFR conditions and the presence of moderate turbulence. The pilot also performed several non-standard maneuvers and communications during the departure. While the aircraft's flight control and engine systems showed no evidence of mechanical failure that would prevent normal operation, the investigation noted that the autopilot disengage indicator was likely illuminated at impact. It is possible the autopilot disconnected due to a load factor exceedance or a momentary power loss in the pitch trim adapter, a phenomenon previously observed by the operator.