The 1983 Jökulfirðir (TF-RAN) helicopter crash
The 1983 Jökulfirðir helicopter crash is an aviation accident that happened on 8 November 1983 when TF-RAN (Sikorsky S-76) crashed in Jökulfirðir, Westfjords, Iceland. The helicopter was operated by the Icelandic Coast Guard and was conducting a training flight when an inflight failure caused it to crash and sink into the ocean. The crash is the deadliest in the Icelandic Coast Guards’ history.
Aircraft
TF-RAN was a Sikorsky S-76A bought new by the Icelandic Coast Guard in 1980. It was specially built for coast guard operations and had powerful lifting equipment for rescue operations. The helicopter was given the tailsign TF-RAN after Rán the Norse deity.
Accident
On 8 November 1983 at 22:53 the helicopter took off from the Icelandic Coast Guard’s patrol vessel Óðinn deep in Jökulfirðir, south of Kvíarfjall. Onboard were two pilots along with a flight engineer and navigator. It was going to conduct a training flight around the fjord to practice rescuing using the lifting equipment to pull people up into the helicopter. Only one or two minutes had passed from takeoff when the vessel heard a faint call of distress and saw a flash of light in the sky. Sailors on the patrol vessel tried calling the helicopter but got no answer. It then came clear to them that an accident had occurred. The vessel along with fishing boats in the area immediately started searching for the helicopter. At around 2 in the morning on the 9th of November, a local fishing vessel found several items from the helicopter including parts from the rotor blades, life belt, and helmet. More debris from the helicopter was found later that same night. The helicopter was found just before noon on the 10th of November at a depth of 82 meters about one and a half miles from land north of Höfðaströnd in Jökulfirðir.
Cause
The report for the accident made by the Icelandic Aircraft Accident Investigation Board which was supported by an NTSB representative concluded that the right-hand sliding door separated from the lower track for unknown reasons from the aircraft while in flight and deflected into the main rotor system, subsequently causing a water landing and sinking. The report said that the landing must have been of a low-impact force since the body was in good shape.
The official conclusion is that the sliding door separated from the helicopter at some stage of the flight, due to an unexplained failure of the lower track assembly of the sliding door and was deflected upwards into the main rotor.