What happened
On August 11, 2004, at approximately 10:05 UTC, a Robinson R2/2 Beta helicopter, registration OK-YIT, was conducting a photographic flight near the village of Čeřenice, Czech Republic. The flight, operated by LPS, letecké práce a služby, s.r.o., involved a pilot and a passenger acting as a photographer. The mission involved maneuvering over the target area to capture images of a residence.
While performing turns at an altitude of approximately 150 meters, the aircraft experienced significant lateral oscillations, with bank angles reaching up to 45 degrees, and a tendency to yaw to the left. The pilot interpreted these flight characteristics as a potential tail rotor failure and initiated an emergency landing procedure toward a forest clearing. However, the aircraft struck a large tree in a wooded area before reaching the intended landing site. The impact caused the destruction of the aircraft, and the passenger sustained fatal injuries, while the pilot suffered serious injuries.
The investigation
The ÚZPLN investigation examined the aircraft's technical condition, the pilot's experience, and the environmental conditions at the time of the accident. Because the Robinson R22 Beta was not equipped with a flight data recorder, investigators reconstructed the flight sequence using witness statements, pilot testimony, and aerodynamic principles.
Technical inspections of the wreckage, including the main rotor blades and the tail boom, revealed no mechanical defects. The investigation also considered the aircraft's weight and balance, noting that due to high ambient temperatures, the helicopter was operating at a weight of 620 kg, very close to its maximum takeoff weight of 622 kg. Furthermore, investigators noted that the pilot's experience on this specific type of helicopter was relatively low, having flown only 110 hours on helicopters.
Findings
- The primary cause of the accident was the pilot's incorrect reaction to turbulence encountered while flying over hilly terrain, leading to improper procedures during the emergency.
- The pilot misidentified aerodynamic disturbances caused by turbulence as a mechanical failure of the tail rotor.
- The aircraft was operating near its maximum takeoff weight in high temperatures, which negatively impacted flight characteristics.
- The aircraft's flight path was likely disrupted by vertical air currents (updrafts or downdrafts) of up to 5 m/s, causing the significant bank angles observed.
- The pilot's limited experience in managing complex flight situations in turbulent environments contributed to the sequence of erroneous decisions.