What happened
On September 28, 2013, at approximately 14:00 LMT, an incident occurred at the Kruszyn airfield (EPWK) during winch launch training operations. A driver, operating the vehicle used to retrieve the winch cable, was approaching a KR-03A Puchatek glider. As the vehicle reached approximately 15 meters from the aircraft, the driver slowed down and shifted into the lowest gear.
While attempting to stop the vehicle roughly 4 to 5 meters in front of the glider, the driver depressed the clutch pedal. However, due to an improper foot position, the foot slipped from the pedal. Because the engine's idle speed had been increased to ensure smoother operation, the vehicle moved forward upon re-engaging the gear. The vehicle continued straight, striking the nose of the glider and causing structural damage to the aircraft's nose section.
The investigation
The investigation, conducted by the aircraft user's commission, established that the incident took place following a period of heavy rain, which left the airfield grass wet and slippery. The driver was wearing wet footwear, which contributed to the loss of friction on the vehicle's controls. The investigation also confirmed that the driver was not under the influence of alcohol, as a breathalyzer test performed by local authorities returned a negative result.
Findings
- The driver made an improper decision to drive toward the center of the glider rather than toward the wingtip.
- The driver failed to react appropriately to the vehicle's movement, failing to brake or steer around the aircraft.
- The driver's foot slipped from the clutch pedal due to improper positioning.
- The slippery conditions of the wet grass and the driver's wet footwear reduced the necessary friction between the foot and the pedal.