Bristow Helicopters Flight 56C

Bristow Helicopters Flight 56C was a helicopter flight that flew between Aberdeen and the Brae Alpha oil rig in the North Sea. On 19 January 1995, the AS 332L Super Puma helicopter operating the route, registered G-TIGK and named Cullen, was struck by lightning. The flight was carrying 16 oil workers from Aberdeen to an oil platform at the Brae oilfield. All 18 people on board survived.

Accident

En route, the helicopter ran into poor weather and was then struck by lightning. This caused severe damage to the tail rotor. Though the helicopter managed to limp for a few more minutes, the tail rotor eventually failed completely when the copilot tried to test if his controls were still working and the pilots were forced to perform an emergency autorotation onto the rough seas. Emergency flotation devices on the helicopter allowed the passengers and crew to be evacuated onto a life raft. Despite the high waves and bad weather, all the people on board the flight were rescued by the standby rescue ship Grampian Freedom.

The lightning strike was an isolated one in the storm, and may have been induced by the helicopter flying through the cloud. The accident investigation also revealed potential troubles with the carbon fibre composite material with brass strip design of the rotors which made the rotorblades prone to explosion and damage from lightning strikes.