On 13 August 1981 the helicopter lost power to the main rotor gearbox, going out of control during the ensuing autorotation.

[3] G-ASWI left the North Denes airfield at 13:47 on Thursday 13 August 1981 on a routine passenger and freight flight between rigs on the Leman and Indefatigable gas fields.

At 15:41, returning from the Leman field to the landing site at Bacton, the commander, Ben Breach,[4] sent a distress message reporting that he was ditching due to engine failure.

A Royal Air Force Search and Rescue Westland Sea King left RAF Coltishall at 15:47, sighting floating wreckage from G-ASWI at 15:57.

[10] A major article on the ongoing effects of the crash was published in the Eastern Daily Press in September 2014.