What happened
On April 16, 2000, a PZL-104 Wilga 35 was conducting sightseeing flights at an improvised landing site near Kospoda, Thuringia, as part of a local community festival. The flight was operating under a special permit for out-of-field takeoffs and landings. During the return leg of the flight, the pilot performed a landing approach that was noted by witnesses to be relatively high, transitioning into a steep descent in the final phase.
The pilot attempted to flare the aircraft at an altitude of approximately 5 to 8 meters. Due to the low airspeed and the height of the flare, the aircraft sank into the ground, resulting in a heavy impact. The force of the landing caused the upper shock absorber mounting of the right main landing gear to fail. Following the gear collapse, the aircraft overturned and came to rest on its back. The accident resulted in one serious injury to the pilot and three minor injuries to the passengers. The aircraft was destroyed.
The investigation
The BFU examined the technical condition of the aircraft, the meteorological conditions, and the suitability of the landing site. The investigation confirmed that the aircraft had been regularly maintained, was properly registered, and that the weight and balance were within limits. No technical defects were found in the airframe or engine prior to the impact.
Investigators also reviewed the landing site specifications. The temporary strip, marked with cones, measured 510 meters in length and 20 meters in width, which did not meet the 600-meter requirement specified in the flight permit. Additionally, the longitudinal slope of the strip was approximately 4%, exceeding the permitted 2% limit. However, the investigation determined that these site dimensions were not the primary cause of the accident.
Findings
- The primary cause of the accident was a hard landing caused by an excessive flare during the final approach.
- Significant wind conditions contributed to the instability; the area was experiencing gusty, turbulent surface winds from the southwest, exacerbated by local terrain and nearby vegetation.
- The pilot's decision to fly a higher approach to avoid turbulence led to a loss of airspeed, causing the aircraft to drop abruptly during the flare.
- The structural failure was specifically identified as a ductile fracture of the upper shock absorber mounting on the right main landing gear.