G-BEID was a

Sikorsky S-61 The Sikorsky S-61L and S-61N are civil variants of the SH-3 Sea King military helicopter. It was developed and produced by the American helicopter manufacturer Sikorsky Aircraft. The commercial version of the Sea King was developed during the ...

N helicopter of

British International Helicopters British International Helicopter Services (BIH), owned by Bristow Group, is a British-owned helicopter operator. It operates a fleet of ten helicopters covering search and rescue, offshore, defence, charter and flying training activities from i ...

which made a controlled ditching in the sea northeast of

Sumburgh Sumburgh is a small settlement in the Shetland Islands, Scotland. Sumburgh is located at the south end of the Mainland on Sumburgh Head. Sumburgh Airport is just outside the village to the north. Sumburgh has a population of approximately 100. Ja ...

on 13 July 1988 following an engine fire. There were no fatalities.

Accident

The helicopter left the ''Safe Felicia''

semi-submersible Semi-submersible may refer to a self-propelled vessel, such as: * Heavy-lift ship, which partially submerge to allow their cargo (another ship) to float into place for transport *Narco-submarine, some of which remained partially on the surface * ...

oil platform in the

Forties oilfield The Forties Oil Field is the second largest oil field in the North Sea, after the Clair oil field, which is located 110 miles east of Aberdeen. It was discovered in 1970 and first produced oil in 1975 under ownership of British Petroleum, now ca ...

at 13:45 with 2 pilots and a full load of 19 passengers for the one hour flight to Sumburgh Airport on the

Mainland Mainland is defined as "relating to or forming the main part of a country or continent, not including the islands around it egardless of status under territorial jurisdiction by an entity" The term is often politically, economically and/or dem ...

of Shetland. At 14:28 the co-pilot (who was flying) reported hearing a muffled bang which was also heard by some of the passengers, from the area of the No. 2 engine transmission. Shortly after, the No. 2 engine's fire warning lights came on. The pilot immediately began a descent and transmitted a distress call. About 48 seconds after the noise, the No. 2 engine was shut down and the fire extinguisher triggered. The No. 1 engine fire warning then also illuminated, while passengers saw oil leaking from the cabin ceiling. The pilot advised the passengers to prepare for an emergency ditching and took control of the aircraft. The floats were deployed and a gentle ditching was made about 3 minutes after the initial noise had been heard, by which time the helicopter's cabin had filled with smoke. All 21 occupants evacuated on to liferafts and were then winched up into a Search and Rescue helicopter. After a strong fire consumed most of the floating helicopter, the remains broke up and sank.

Investigation

A recovery operation was mounted using the DSV (

diving support vessel A diving support vessel is a ship that is used as a floating base for professional diving projects. Basic requirements are the ability to keep station accurately and reliably throughout a diving operation, often in close proximity to drilling or ...

) ''Stena Marianos'' which arrived on site on 16 July 1988. The aft fuselage section was raised the following day and the forward section shortly after. The recovery operation had to be ended on 19 July before finding the engines or transmission components due to the ''Stena Marianos'' having other commitments. The recovery continued on 2 August using the DSV ''Norskald'', and the engines, main rotor, and transmission were located and raised on 5 August.

Cause

It was concluded that the fire had occurred in the helicopter's main gearbox, probably resulting from the effects of a bearing failure in the No. 2 engine. A further factor was the lack of fire detection or suppression capability within the gearbox bay. The cause of the bearing failure could not be definitely established.

Safety recommendations

The AAIB made a list of 27 safety recommendations to the CAA. These addressed improvements in maintenance, early detection of problems, emergency escape equipment, documentation and training provisions, and firewall integrity. Most of these were accepted by the CAA.CAP 594
''Civil Aviation Authority'' May 1991

Notes

References

* {{DEFAULTSORT:British International Helicopters Sikorsky S-61n Crash, 1988 Airliner accidents and incidents caused by mechanical failure Aviation accidents and incidents in 1988 Aviation accidents and incidents in Scotland Aviation in Shetland 1988 in aviation Accidents and incidents involving the Sikorsky S-61 British International Helicopters accidents and incidents July 1988 events in the United Kingdom