What happened
On February 15, 1996, a Robinson R22 Mariner helicopter, registration OH-HEW, was performing a scheduled mail delivery flight in the Rymättylä region of Finland. The flight, operated by Helikopteripalvelu Oy, was part of a contract with Suomi Posti Oy to distribute mail across the archipelago during the spring thaw.
During the seventh landing of the mission at Pakinais Island, the pilot attempted to land on ice in front of a pier. However, strong winds pushed the aircraft toward the shore. In an attempt to abort the landing and climb away, the pilot initiated a turn that led the helicopter into nearby trees. The aircraft struck a birch tree, causing the main rotor blades to strike the trunk and the helicopter to crash onto its right side. The pilot sustained minor injuries, while the mail carrier on board was uninjured.
The investigation
The investigation examined the aircraft's mechanical condition, the pilot's recent experience, and the prevailing weather conditions. Investigators found no technical failures in the aircraft's systems. The inspection of the wreckage revealed significant damage, including broken rotor blades, a fractured tail boom, and damaged cockpit structures.
Investigators also reviewed the pilot's flight history and noted that while the pilot was experienced on other types, such as the Bell 206, he had very limited recent experience with the R22 Mariner, specifically the version equipped with floats. The investigation also looked into the engine's intake pre-heater, which had been left in the hot position, slightly reducing engine power.
Findings
- The primary cause of the accident was the decision to continue flight operations in strong, gusty winds that significantly hindered aircraft control.
- The pilot's loss of control was immediately triggered by performing a takeoff into a crosswind and initiating a turn into a tailwind at a low airspeed.
- The pilot had an incorrect perception of the wind direction.
- The pilot's recent experience with the R22 Mariner, particularly the float-equipped variant, was minimal, with only five previous flights in this specific type.
- The engine's performance was slightly degraded because the intake air pre-heater was left in the hot position.