What happened
On December 5, 1997, a Robinson R22 Beta helicopter, registration OH-HWB, was conducting a training flight in Lempäälä when it sustained substantial damage. The flight was part of a commercial pilot training program, intended to review landing procedures, approach sectors, and various landing techniques.
During the flight, the pilot decided to deviate from the planned syllabus to perform an autorotation maneuver—a simulation of an engine failure—which had not been scheduled for this flight phase. While performing the maneuver over an unfamiliar field, the pilot initiated the final approach at approximately 10 meters of altitude. During the pull-up, the tail rotor struck the ground. The pilot attempted to correct the resulting rightward turn by applying left pedal and increasing power, but the aircraft completed nearly a full rotation before impacting the ground on its left side, causing the left landing gear to break.
The investigation
The investigation examined the pilot's training progress, the flight conditions, and the presence of unauthorized personnel on board. Investigators found that the pilot's helicopter private pilot license had expired on November 24, 1997, and the training director had failed to verify the validity of the pilot's credentials.
Furthermore, the investigation looked into the presence of a second student as a passenger. While the flight was designated as a solo training flight, the presence of another student likely influenced the pilot's decision to perform the unauthorized maneuver. The investigation also analyzed the terrain and weather, noting that the landing site was a snow-covered field under overcast conditions.
Findings
Several factors contributed to the accident:
- The pilot chose to perform autorotation exercises outside of the prescribed training syllabus.
- The presence of another student as a passenger likely created a desire to demonstrate skill, influencing the decision to perform the maneuver.
- The pilot performed the maneuver over an unfamiliar landing site.
- Overcast weather conditions (shadow ceilings) prevented the pilot from detecting a significant mound in the middle of the field.
- The undisturbed snow cover on the field made it difficult to accurately judge the aircraft's height above the ground.
- The pilot was operating with an expired pilot license.