What happened
On March 24, 2019, a Glaser Dirks DG-800B motor glider, registration D-KICB, was performing a takeoff from runway 16 at the Igualada-Ódena aerodrome in Barcelona. During the initial climb, at an altitude of approximately 50 meters, the pilot radioed an emergency due to an engine failure.
Following the loss of power, the pilot initiated a left turn, likely in an attempt to return to the airfield. During this maneuver, the aircraft's speed decreased, and the increased bank angle caused the aircraft to enter a stall. The aircraft subsequently entered a spin and impacted the ground in a near-vertical descent. The pilot sustained fatal injuries, and the aircraft was destroyed.
The investigation
The investigation examined the wreckage and the engine components. Although the engine was found in its retracted position within the compartment, investigators determined that the engine had actually been deployed during the flight and only retracted due to the force of the impact, which broke the electrical actuator support.
Technical analysis of the Solo 2 625 01 engine revealed that the crankshaft had fractured into two parts. Microstructural and macro-morphological examinations showed that the failure was caused by a progressive fatigue process resulting from bending and torsional stresses. Investigators also found evidence of potential seizing (gripado) in the bearings, characterized by overheating and material deformation, as well as corrosion on the shaft. While the aircraft's recent maintenance documentation could not be located, the last available airworthiness review from 2017 indicated the engine had 116 hours of operation.
Findings
- The primary cause of the accident was the loss of control due to an aerodynamic stall.
- The engine failure was caused by a crankshaft fracture resulting from fatigue, driven by bending and torsional stresses caused by shaft misalignment.
- The presence of bearing seizure and corrosion suggests that previous mechanical issues, such as lubrication defects or contamination, may have contributed to the shaft misalignment.
- The aerodynamic drag produced by the engine being in the extended position during the turn contributed to the rapid loss of airspeed and the subsequent stall.