The Transportation Safety Board is recommending several key safety improvements to offshore helicopter travel in a report released Wednesday on the crash of a Sikorsky helicopter that killed 17 people off the coast of St. John's.

After investigating the crash of Cougar Helicopters Flight 491, the board says helicopters must:

  • Have a main gearbox able to run without oil for 30 minutes.
  • Not fly in rough conditions.
  • Have emergency breathing equipment on all flights where survival suits are worn.
  • Have an emergency flotation system to keep a chopper afloat long enough to evacuate safely.

"There was a complex equation of 16 factors involved in this accident," board chair Wendy Tadros said in St. John's on Wednesday. "No one factor stands out above the others.

"The manufacturer, the regulator and Cougar have largely addressed the problems that have been identified, but risks still exist."

Cougar Flight 491 crashed 11 minutes after one of its two pilots reported the helicopter's gearbox was losing oil pressure on March 12, 2009.

The S92A chopper, made by U.S.-based Sikorsky Aircraft Corp., slammed into the Atlantic Ocean 55 kilometres southeast of St. John's. Both pilots and 15 passengers died, and there was one survivor, Robert Decker.

The helicopter was ferrying workers to offshore oil-production platforms hundreds of kilometres east of St. John's.

Gearbox still potential problem

The board's Mark Clitsome said the Sikorsky S92A still cannot run without oil for 30 minutes.

"The Sikorsky S92A came to be certified without a 30-minute run-dry time. The studs have changed, but the gearbox has not changed and in the event of catastrophic oil loss, the S92A would still crash in 11 minutes."

Tadros said the aviation industry in general and Sikorsky specifically must improve the helicopters it makes.

"We recommend that all category A helicopters, including the S92A, be able to fly for at least 30 minutes following a massive loss of main gear box oil," she said.

The safety board wants the U.S. Federal Aviation Administration to reconsider whether a 30-minute run time is sufficient in the areas where offshore helicopters operate.

"We want the FAA to look at today's operating environment — Hibernia, the Arctic, the North Sea, any of those extreme locations — and decide whether even 30 minutes is enough time," she said.

"If the 30-minute requirement is negated by the extremely remote provision, it needs to go; it's as simple as that."

Emergency floatation system necessary  

The board report said that if a helicopter is working in an area where it might have to ditch in rough waters, it must be equipped with emergency flotation system able to keep it afloat long enough for everyone on board to evacuate safely.

"If it can't do that … if a helicopter isn't up to the task, it shouldn't be operating, period," Tadros said.

The board's final recommendation relates directly to the cause of death of the 17 cougar crash victims.

"All 17 victims of flight 491 died of drowning," Tadros said. "That is why passengers and crew on flights off the shores of Newfoundland are now being provided with emergency underwater breathing apparatus.

"But to make sure that passengers in the rest of Canada have the same chance for survival, the board is calling for emergency breathing equipment on all flights where survival suits are worn."

The brother of one of he passengers who died hopes offshore safety will be improved by the board's investigation.  

"He would've like to have seen these recommendations enacted so that his friends and co-workers who fly in that trade will have a modicum of safety anyway. It is a harsh violent world we live in when we're talking about the North Atlantic,"said Harold Mullowney, of Bay Bulls, whose brother Derrick Mullowney died in the crash.

Broken titanium studs confirmed

The board confirmed what Transportation Safety Board investigators initially suggested was the cause of the crash.

On March 20, just over a week after the crash, investigators discovered broken mounting studs on the helicopter's main gearbox filter bowl when they started their examination of the helicopter wreckage.

On Wednesday, the board's Mike Cunningham explained that the pilots were warned that there was a problem when a red warning message appeared in the cockpit indicating low oil pressure in the main gear box.


A Transportation Safety Board of Canada photograph of the recovered Sikorsky oil filter housing showing one of three mounting studs broken and missing. (Courtesy of TSB)

"What they didn't know is that two of the three main gearbox mounting studs had broken," Cunningham said. "And when they broke, the helicopter lost oil rapidly and the gears began to overheat. It crashed into the Atlantic just 11 minutes after the first indication of trouble."

The Sikorsky Aircraft Corp. was aware of problems with its mounting studs. On Jan. 28, the U.S. manufacturer issued an alert saying that the titanium mounting studs should be replaced by steel studs on every helicopter within a year, or within 1,250 flight hours.

Months earlier, during the summer of 2008, Sikorsky, the Transportation Safety Board and the FAA were aware of the possibility of the titanium studs breaking.

On July 2, 2008, a Sikorsky S92A 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.