What happened
On September 12, 2022, a Daher Aircraft Design Kodiak 100 was conducting a training flight for a class rating at Rendsburg-Schachtholm. The flight crew included a flight instructor, a student pilot, and the aircraft owner acting as a passenger. The training session involved practicing various maneuvers, including steep turns and slow flight.
During the final approach, the instructor initiated a spontaneous training scenario intended to teach the student how to manage critically low airspeeds without the use of flaps. The plan was to allow the aircraft to reach a near-stall condition and then execute a recovery by pitching the nose down to unload the wing and subsequently applying maximum power. After an initial attempt at a go-around, the instructor instructed the student to repeat the maneuver.
As the student reduced speed to the point of a stall warning, the instructor reduced engine power to further challenge the student. Although the student attempted to pitch down and increase power, the engine response was delayed. The aircraft lost altitude rapidly and struck a field approximately 258 meters before the threshold of runway 21. The impact caused the nose gear to collapse and the aircraft to slide approximately 70 meters on its cargo belly pod. The instructor sustained one minor injury, and all occupants were able to egress the aircraft.
The investigation
The BFU examined the aircraft' and the flight data recorded by the Garmin G-1000 avionics system. The investigation focused on the engine's performance, the flight profiles, and the training procedures. Investigators found no evidence of mechanical failure or technical impairment of the aircraft. However, they noted that the Fuel Condition Lever was difficult to move just before reaching the HIGH IDLE stop, which likely prevented the lever from being fully advanced during previous maneuvers. This resulted in the engine operating from a much lower NG (gas generator speed) than expected during the accident, contributing to the perceived delay in power application.
Findings
- The primary cause was an insufficiently high starting altitude for a spontaneously initiated training maneuver that was not part of the approved syllabus.
- The altitude was inadequate to allow the aircraft to transition from a critically low airspeed and idle power to a stabilized flight state with maximum power.
- The instructor's decision to repeat the maneuver at a low altitude, without prior discussion or planning, significantly reduced the safety margins.
- The Fuel Condition Lever was likely not pushed fully to the HIGH IDLE position due to mechanical resistance, leading to a delayed engine spool-up during the recovery attempt.