Four people were killed in the crash of a Eurocopter AS332L2 Super Puma in the North Sea near Sumburgh on 23 August, Scottish police have confirmed.

Eighteen people were on board the rotorcraft, operated by CHC Helicopter. Fourteen were treated in hospital in Lerwick, including the two crew. Five were discharged and nine detained overnight "either for observation or suffering from exposure", say police.

CHC Helicopter confirms that the UK's Air Accident Investigation Branch has dispatched representatives to conduct a probe into the accident.

The AS332L2 ditched about 2nm west of Sumburgh. It was on approach to Sumburgh airport when contact with air traffic control was lost at about 18:30 local time. The helicopter had flown from Aberdeen to the North Alwyn oil and gas platform, before departing for the Borgsten Dolphin rig.

Canada-based CHC confirms that it has temporarily suspended operations of all AS332L2 aircraft "until more information is available". CHC is conducting no flights in Aberdeen on 24 August.

In April 2009, a Bond Offshore Helicopters AS332L2 crashed in the North Sea after catastrophic failure of the main rotor gearbox. All 16 on board were killed.

Source: Flight International