What happened
On June 20, 1998, a Robinson R22 Beta helicopter, registration OH-HPT, was performing a private flight over Ekenäs, Finland. The pilot, intending to show a passenger the area from the air, began his final approach to a landing site at the Strand Hotel.
During the approach, the pilot attempted to determine the wind direction by observing flags on flagpoles behind the hotel. He misidentified the wind direction, leading him to initiate a landing approach into a tailwind. This maneuver caused the aircraft to enter a vortex ring state. Despite the pilot increasing power, the helicopter continued to descend rapidly. The aircraft eventually struck the water in a coastal area, causing the helicopter to capsize onto its left side. The pilot and passenger were able to exit the aircraft on land without injuries.
The investigation
The investigation examined the aerodynamic conditions of the flight, the pilot's flight experience, and his physical condition. Investigators analyzed the mechanics of the vortex ring state and how the tailwind approach contributed to the loss of lift.
Medical examinations were conducted following the incident. While the pilot's blood alcohol level was 0.0, urine analysis revealed the presence of tetrahydrocannabinol acid (a metabolite of cannabis) and amphetamines. Additionally, investigators reviewed the pilot's recent history, noting that he had been celebrating Midsummer Eve until approximately 06:00 that morning, leaving him with only about eight hours of rest before the flight, which was contrary to established safety guidelines regarding recovery time.
Findings
- The primary cause of the damage was the approach into a tailwind, which induced a vortex ring state.
- The pilot's limited flight experience contributed to the accident, as he was unable to perform the necessary corrective maneuvers—such as increasing forward airspeed—in a timely manner.
- The presence of drugs (cannabis metabolites and amphetamines) in the pilot's system could not be ruled out as a contributing factor to the accident.
- The pilot's insufficient rest period following a night of celebration further compromised flight safety.