Text of the statement released by the FAA late today.
Cougar Helicopters Flight 91
In Greek mythology, when Achilles was a baby, it was foretold that he would die young. To improve his chances of immortality, his mother, Thetis, took Achilles to the River Styx, which was supposed to offer powers of invulnerability, and dipped his body into the water. But Thetis held Achilles by the heel… The rest of the myth is well known. If the mother of the helicopter concept ever dipped it into the River Styx, she probably held it by the main gearbox.
In another safety issue affecting the Sikorsky S-92 helicopter’s main gearbox, on July 18 the FAA released an airworthiness directive (AD) that calls for inspection for cracks. The AD was prompted by the discovery of a crack in the gearbox housing of one S-92, “in the cored passage area adjacent to the scissor bracket mount,” allowing oil to leak. The result could be a loss of oil and subsequent failure of the gearbox, the FAA said.
The FAA is moving to redefine what “extremely remote” means when it comes to Part 29 certification provisions regarding loss of helicopter gearbox lubrication. The S-92 originally gained certification after Sikorsky convinced the FAA that complete loss of lubrication was extremely remote. Failure of the main rotor gearbox lubrication system is blamed for the fatal ditching of a Cougar Helicopters S-92A off Newfoundland in March 2009.
Although Sikorsky is developing a new main gearbox to solve the problems that have plagued the S-92 over the course of its service life, the new transmission will not be able to run for 30 minutes after a total loss of lubrication.
Sikorsky is developing a next-generation main gearbox (MGB) with enhanced lubrication capabilities with built-in redundancy systems such as chip detectors and oil scavenge systems, according to Spencer Elani, Sikorsky’s S-92 program manager. “We are continuing to make a lot of improvements to the current gearbox, and to automate some of the features,” Elani said.
The chairman of Canada’s Transportation Safety Board (TSB) wants a mandatory 30-minute “run dry” requirement on all main gearboxes (MGB) for future helicopters. Wendy Tadros’s remarks came as part of the TSB’s investigation of the March 2009 fatal crash of a Sikorsky S-92A off Newfoundland, 11 minutes after its MGB ran out of oil.
In an open letter to Canada’s minister of transport, the lawyer representing the families of the passengers killed in, and the sole survivor of, the March 2009 crash of Cougar Helicopters Flight 491 has challenged the certification Transport Canada granted to the Sikorsky S-92A in 2005. The accident helicopter, which ditched 30 nm east of St. John’s, Newfoundland, and Labrador, was carrying 18 people.
Canadaπs Transportation Safety Board (TSB) issued its final report February 9 on the fatal 2009 accident of a Cougar Helicopters Sikorsky S-92A off Newfoundland that killed 17. The helicopter crashed while attempting to ditch after its main gearbox lubrication system failed due to two cracked oil filter bowl mounting studs.
Canadaπs Transportation Safety Board (TSB) yesterday issued its final report on the fatal accident of a Cougar Helicopters Sikorsky S-92A off Newfoundland that killed 17 on March 12, 2009. The helicopter crashed while attempting to ditch after its main gearbox lubrication system failed due to two cracked oil filter bowl mounting studs.