The helicopter was on a 65-min flight from Troughton Island to the drilling vessel Energy
Searcher. The flight departed Troughton Island at 0717 hours Western Standard Time with
thirteen passengers and two crew on board.
Approximately 30 min after takeoff, while cruising at 4,500 ft, a loud bang was heard
accompanied by the onset of severe airframe vibration. The pilot immediately lowered the
collective pitch control and reduced the helicopter's speed, while the co-pilot transmitted a
distress message and instructed the passengers to fasten their seat belts.
Although the vibration made reading of the instruments difficult, the pilot was able to
determine that main rotor RPM was approaching 120%. The pilot increased the collective
pitch in an attempt to control the main rotor RPM but this caused the vibration level to
increase. He then lowered the collective pitch control, turned the helicopter into wind, and
established an autorotative descent. The pilot observed that one main rotor blade was tracking
irregularly. Passing 1,000 ft, the automatic inflation system for the flotation bags was armed.
The helicopter contacted the water surface at a forward speed of 10-15 kts approximately
parallel to the swell. The flotation bags immediately began to inflate. At the same time the
main rotor blades struck the water, causing the fuselage to roll right until inverted. During the
rollover, the left and right cabin windows were forced from their frames and the left side
hinged door forced open. All passengers escaped from the cabin through these openings. The
pilots exited through their respective doors, the co-pilot taking a portable emergency locator beacon.
The short time interval between touchdown and the rollover prevented deployment of the life
rafts. However, one raft was later released by a passenger.
The survivors were located a short time after the ditching by a search aircraft and were later
rescued by another helicopter and transferred to Troughton Island.