What happened
On August 11, 2019, a Scheibe SF 25 C motor glider was performing a solo flight at the Füssen glider airfield as part of a refresher training session. During the landing phase on runway 08, the aircraft experienced a bouncing effect upon initial contact. This was followed by a second, much harder touchdown that caused the propeller to strike the ground, resulting in significant damage to the propeller blades.
Following the impact, the pilot applied full power to initiate a go-around. As the aircraft climbed to an altitude of approximately 30 meters AGL, the pilot attempted to enter a right-hand turn. During this maneuver, the aircraft entered an uncontrolled flight state, banking sharply over the right wing and subsequently impacting the ground. The impact caused the destruction of the aircraft and left the pilot with serious injuries to the head, leg, and hand.
The investigation
The BFU investigation examined flight data from the aircraft's FLARM collision warning system, which confirmed that the aircraft's speed during the final approach was approximately 100 km/h—well above the recommended 90 km/h. The data also showed that during the climb, the aircraft's speed steadily decreased until it reached 64 km/h, which was below the minimum flight speed required for stable flight.
The investigation also reviewed the aircraft's condition and the pilot's experience. The aircraft was found to be airworthy and within weight limits, with no technical defects identified in the engine or controls. The pilot held a valid license but had relatively limited experience specifically with motor gliders and had recently undergone refresher training.
Findings
- The primary cause of the accident was that the motor glider entered an overstressed flight condition because the pilot failed to maintain the necessary airspeed required for a banked turn during the go-around.
- The initial landing approach was flown at an excessive speed, which prevented the aircraft from achieving the correct landing configuration (tail-low) and led to the bouncing and subsequent hard touchdown.
- The pilot likely experienced mental overload while attempting to manage the bouncing aircraft, which led to a delayed decision to initiate the go-around.
- The pilot failed to recognize the significant reduction in available engine performance and the vibrations caused by the propeller damage.
- The aircraft was flying at a speed below the minimum flight speed during the horizontal flight phase, leaving insufficient energy to recover from the turn.