On March 12, 2009, while carrying workers headed to the Grand Banks oil field off the coast of Newfoundland, Cougar helicopter flight 491 attempted an emergency “ditch” about 55 km from its point of origin in St. John’s, NL. A single person survived. The other 17 on board drowned. Just prior, the pilots radioed that they had lost oil pressure.
Through the accident inquiry, it was discovered that a titanium bolt in the main gearbox failed, causing rapid oil loss. The Sikorsky S-92 helicopter was subsequently unable to fly for 30 minutes after loss of oil. The helicopter had been exempted from a 30-minute run-dry requirement because Sikorsky argued that the chances of gearbox oil loss were “extremely remote.” Flight 491 was only able to continue for 10 minutes after a loss of oil. Had they been able to continue for another 20 minutes, the helicopter perhaps could have made it back to St. John’s.
An accessible but detailed article, “The End of Mystery” by Chris Jones and published in Esquire, about the investigation into the Cougar helicopter crash can be read here.
Tags: Cougar Crash