What happened
On June 28, 2019, a private flight involving a RotorWay EXEC 162F (registration LN-OSV) ended in an accident on private property in Veland, Strand municipality. The pilot was performing a short flight from a private landing site to Tau and back, accompanied by one passenger.
While attempting to land, the pilot entered a hover with the nose pointing south. During this maneuver, the aircraft began an uncontrolled 360-degree leftward rotation despite the pilot applying full right pedal. To avoid further complications, the pilot aborted the landing attempt to initiate a new approach. However, as the pilot attempted to climb and turn right, the rotation recurred. To maintain control, the pilot decided to land the aircraft on the grass. Upon contact with the ground, the helicopter tipped forward, causing the main rotor to strike the earth, before rolling onto its left side.
Both occupants escaped the wreckage with only minor cuts, though the aircraft sustained substantial damage to the cockpit, tail boom, main rotor, and landing gear.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the wreckage and interviewed the pilot. The investigation confirmed that the aircraft was within its maximum takeoff weight and that no mechanical failures were present in the tail rotor, the pedal linkages, or the tail rotor drive system. Maintenance records showed the aircraft had recently undergone a 100-hour inspection and that tail rotor drive belts had been replaced shortly before the flight.
Findings
- The primary cause of the uncontrolled rotation was Loss of Tailrotor Effectiveness (LTE).
- With winds from the southwest hitting the aircraft from the right, the main rotor's downwash likely created descending air currents that disrupted the airflow around the tail rotor.
- The pilot's decision to land on the grass was a necessary action to prevent a total loss of control during the secondary rotation.
- The sloping terrain of the landing site and limited maneuvering space—constrained by nearby power lines and a building—contributed to the aircraft's inability to stabilize and eventually led to the rollover.
Safety action
- The investigation highlights the necessity of selecting landing sites that remain suitable for operations under various wind directions.