Cougar, which until that day in March 2009 had a stellar safety record, was one of the first helicopter operators in the world to use a new design of helicopters – the Sikorsky S92. It was billed as state-of-the-art for speed, efficiency and safety.

In Cougar 491, Linden MacIntyre shows that worries about the S92 arose eight months before the Newfoundland crash. Near Broome, Australia, an S92 was forced to make an emergency landing. Everyone on board survived, but the Canadian owners of that S92 wanted an independent analysis of the S92 and asked the Transportation Safety Board of Canada to oversee one. The finding: two titanium studs, securing the oil filter system, fractured and came loose with a catastrophic loss of the lubricating oil that allows the blades to rotate and keeps the helicopter in the air.

Both the U.S. Federal Aviation Administration and Sikorsky were informed of the TSB findings. For five months, there was no significant action from Sikorsky. Finally, in January of 2009, Sikorsky issued an alert to operators of S92s, telling them to replace the titanium studs within a year or 1250 flying hours. Just two months after that alert, Cougar flight 491 crashed into the Atlantic.

In addition to revealing new details of events that led to the crash, the fifth estate talks to surviving family members, putting the tragedy into its starkest human terms.