New Delhi: The Sumburgh disaster remains one of the deadliest helicopter crashes in history, and to some, it was possibly the deadliest. It took place on November 6, 1986, when a Boeing-Vertol Model 234LR Chinook helicopter which was bringing back workers from the Brent oilfield crashed while approaching the land at the Sumburgh Airport which is located in the Shetland Islands. The helicopter was just 4 km from the runway when it had a forward transmission failure and its tandem rotor blades collided.
The events leading up to the crash
The Aberdeen Airport was the normal base of the helicopter but since November 3, 1986, it was based at the Sumburgh Airport. On November 6, there was an oil leak from the engine gearbox which delayed its first flight. After its rectification, the helicopter left Sumburgh for Brent Field with 40 passengers.
The aircraft visited three platforms and exchanged passengers and freight before departing Brent Platform C with 44 passengers for return to Sumburgh Airport. It flew at 2,500 feet and as it came near Sumburgh, the helicopter was cleared to descend to 1,000 feet. When it was 7.2 km away from the airfield, the helicopter was cleared by the controller to land on runway 24.
The accident and the crash
As per the cockpit voice recorder, the crew probably experienced an increase in the noise level on the flight deck before there was a bang. No control worked in the aircraft and from a height of 150 feet, it fell towards the sea. As the rotor blades clashed mid-air, the helicopter was destroyed and it quickly sank in the sea. The accident killed 43 passengers and two crew members.
A search and rescue Sikorsky S-61 helicopter reported liferafts in the sea. The helicopter saw a survivor and while rescuing him, another survivor was noted. They were taken to the hospital and search did not find any more survivors.
What caused the accident?
The accident took place due to a modified bevel ring gear’s failure in the forward transmission and as a result, the synchronisation was lost and twin rotors collided. The Air Accidents Investigation Branch (AAIB) also pointed out the previously accepted test programme’s inadequacy and the failure of a stringent inspection programme as causes behind the accident.
A Boeing-Vertol Model 234LR Chinook helicopter which was bringing back workers from the Brent oilfield crashed while approaching the land at the Sumburgh Airport which is located in the Shetland Islands. knowledge Knowledge News, Photos and Videos on General Knowledge
