N.L. chopper’s flaw known in 2008
CBC’s The Fifth Estate has found that the maker of a helicopter that crashed near Newfoundland a year ago, killing 17 people, knew more than six months earlier about the gearbox problem that downed the chopper.
The CBC investigation also revealed that U.S. and Canadian aviation safety organizations knew about theSikorsky helicopter’s flaw in August 2008.
On March 12, 2009, Cougar Helicopters Flight 491 slammed into the Atlantic Ocean 55 kilometres southeast of St. John’s. Both pilots and 15 passengers died, leaving one survivor: Robert Decker, 28.
The S92 chopper, made by U.S.-based Sikorsky Aircraft Corp., was ferrying workers to offshore oil-production platforms hundreds of kilometres east of St. John’s.
It crashed minutes after the pilots reported the helicopter was losing oil pressure.
It was later determined the crash happened after oil leaked from the chopper’s main gearbox, an integral part of the system that turns the helicopter’s main rotors.
“Sikorsky should have been paying attention to this,” said Shawn Coyle, who used to work for Transport Canada as a helicopter test pilot and now works as a consultant to the industry. “Someone in Sikorsky’s organization should have been watching for this sort of thing.”
On March 20, just over a week after the crash, Transportation Safety Board of Canada investigators saidbroken bolts, or studs, securing the oil filter mount to the main gearbox on the helicopter were suspect.
“We went public after we were told by the U.S. Federal Aviation Administration and by Sikorsky that they were planning on taking action,” said the TSB’s Mike Cunningham. “We wanted to make sure that all the operators, worldwide, of S92s got that information in the quickest manner possible.”
Less than two weeks after the crash, the U.S. Federal Aviation Administration ? the organization that had certified the Sikorsky S92 as safe to fly ? grounded all of the choppers and ordered their owners to change titanium studs to steel studs.
It may appear they reacted quickly, but The Fifth Estate’s investigation questions that conclusion. The CBCinvestigation shows that during the summer of 2008, Sikorsky, TSB and the FAA were aware of the possibility of the titanium studs breaking.
On July 2, 2008, a Sikorsky S92 chopper carrying Australian offshore oil industry workers narrowly avoided tragedy after two studs securing the oil-filter assembly to the main gearbox broke and the helicopter lost oil pressure. The pilots were close enough to land to bring the chopper down safely.
Claimed to be safest
The mechanical failure left some people in the helicopter transportation industry with questions about the S92 ? a helicopter Sikorskyadvertised as the safest in the world.The Australian helicopter was owned by CHC Helicopter Corp. of Vancouver. CHC asked Transportation Safety Board of Canada’s West Coast manager, Bill Yearwood, to oversee an independent analysis of what happened to that chopper.
That crucial third-party analysis took place in Richmond, B.C., in the presence of the helicopter’s owners and Sikorsky officials.
An Aug. 29, 2008, summary of that examination written by the TSB noted some troubling findings.
“There appears to be several unresolved issues with the oil system, aside from the fractured studs, on this particular aircraft. It seems likely that these issues are related to stud failures,” the TSB found.
The TSB also noted that: “It is reported the military S92s use steel studs to attach the filter bowl to the transmission.”
FAA told in 2008
In late August of 2008, the TSB advised the FAA of its findings.But it wasn’t until five months later ? on Jan. 28, 2009 ? that Sikorsky issued an alert saying the titanium mounting studs should be replaced by steel studs on every helicopter within a year, or within 1,250 flight hours.
Two months after that, on March 23, 2009 ? more than seven months after the Australian chopper failure ? that the FAA grounded the S92s and ordered the studs changed.
The Fifth Estate ‘s Linden MacIntyre asked Coyle about the time it took authorities and Sikorsky to respond to what they learned in August 2008.
“You tell me, is that a reasonable lapse of time?” he asked.
“Well, in hindsight, no,” said Coyle.
Neither the FAA nor Transport Canada agreed to on-camera interviews requested by The Fifth Estate. Sikorsky also declined repeated requests for an on-camera interview.
S-92 Facts 
Cougar helicopter in Greenland hitches boat ride ashore
Submitted photo
An S-92 operated by Cougar Helicopters in Greenland is lowered to the deck of a supply ship following a problem last week with an over-inflated cell in its fuel tank.
Published on September 14th, 2010
Published on September 14th, 2010
Moira Baird
Topics :
Greenland , East Coast
An S-92 helicopter operated by Cougar Helicopters in Greenland was pulled from service last week following a problem with an over-inflated fuel cell.
It occurred as the S-92 was being refuelled on the deck of the rig Stena Don, which is drilling exploration wells off the coast of Greenland for Cairn Energy.
Hank Williams, Cougar’s East Coast general manager, said the fuel tank did not rupture.
“There was no fuel leak.”
Williams said refuelling takes place once passengers have disembarked from the helicopter.
The helicopter hitched a ride back to shore on a supply boat.
“We could have flown it off the deck, but you don’t do that until you’ve had an inspection of the fuselage,” said Williams.
“The inspection is complete and the aircraft is having the new sponson put on, and hopefully returns to service by Wednesday.”
Fuel cells are located in the sponsons on either side of the S-92.
As a precaution, Cougar sent the old sponson back to Sikorsky for analysis.
Cougar has three S-92 helicopters in Greenland, supporting offshore oil and gas exploration.
The company’s contract with Cairn to transport workers offshore and to provide search and rescue services wraps up at the end of October.