What happened
On May 6, 2006, a Schempp-Hirth Nimbus 2M glider, registration D-KHKA, was performing its first solo flight following a type conversion training session. The flight utilized a retractable engine unit for takeoff. However, during the flight, the pilot encountered a technical difficulty: the propeller failed to reach the correct position to allow the engine unit to be retracted into the fuselage. Consequently, the pilot continued the flight with the engine unit extended.
During the landing phase, the pilot determined that the aircraft would not reach the runway at Zbraslantice Airport (LKZA) and opted to land in a field located before the airfield. During the landing roll, the glider struck a railway embankment. The impact caused significant damage to the forward fuselage near the cockpit, the wing pins, and the wing spar, as well as damage to the engine unit mounting.
The investigation
The ÚZPLN investigation established that the pilot was fully qualified, holding a valid glider instructor rating and medical certificate. The aircraft was airworthy, with all maintenance and required documentation in order. The investigation also determined that the meteorological conditions and the air traffic services at Zbraslavice Airport did not contribute to the accident.
Findings
- The primary cause of the accident was an incorrectly executed landing calculation, which was influenced by the pilot's insufficient experience with this specific aircraft type.
- The pilot proceeded with the flight with the engine unit extended because the propeller failed to feather/position correctly for retraction, a maneuver permitted by the flight manual.
- The pilot underestimated the degraded flight characteristics resulting from flying with the engine unit in the extended position.