What happened
On June 16, 2021, a 73-year-old pilot was conducting a cross-country flight in a Schempp-Hirth Ventus-2cM motor glider. The flight began at the Lüsse landing site using engine assistance. As the flight progressed, thermal conditions in the region north of the Harz mountains deteriorated, leading the pilot to decide to end the flight and return to the airfield using the engine.
During the flight, the pilot was accompanied by another motor glider. As the thermal lift weakened, the pilot attempted to restart the engine to maintain altitude. However, the engine failed to start. Flight data recorders indicate that after a period of steady altitude loss, the pilot attempted an engine start at approximately 228 m AGL. The engine failed to ignite, and the pilot subsequently initiated a turn to approach a landing field.
During the final approach, the aircraft passed through a gap in a tree line at a very low altitude. Witnesses observed the aircraft flying near a truck parked in a field. The aircraft's nose suddenly pitched up sharply before it abruptly pitched forward, resulting in a nearly vertical impact with the ground. The pilot sustained fatal injuries, and the aircraft was destroyed.
The investigation
The BFU examined flight data from the aircraft's LX8080 navigation system, which included an acoustic sensor that recorded engine noise. This allowed investigators to determine that the engine was running briefly during the start attempt but failed to sustain operation. The investigation also included witness statements and an analysis of the aircraft's wreckage.
Investigators found that the fuel line at the outlet of the fuel pump had a tear, which resulted in a leak. While it could not be definitively determined if this leak caused the engine failure, the presence of fuel residue and dirt was noted around the pump and the fuel line. The investigation also noted that the aircraft was not properly configured for landing, as the propeller pylon remained extended and the landing gear was only partially extended and not locked.
Findings
- The primary cause of the accident was a risky off-field landing maneuver that resulted in an uncontrolled flight state.
- The approach speed was too low; the pilot was flying at approximately 90 km/h, whereas the flight manual requires 115 km/h when the propeller is extended.
- The pilot made the decision to attempt an engine start too late, leaving insufficient altitude to execute the necessary emergency procedures or stabilize the approach.
- The pilot lacked recent experience or training in performing off-field landings.
- The aircraft was not properly configured for the landing, specifically regarding the landing gear and the propeller pylon.