The Transportation Safety Board has recommended changes that include ensuring helicopter gearboxes can continue to operate for 30 minutes without oil. (CBC)

An investigation that found a "complex web" of problems caused the 2009 Cougar Helicopters disaster off Newfoundland requires an immediate government response, a politician says.

The Transportation Safety Board reported Wednesday that 16 interconnected factors — including a sudden drop of oil pressure, broken studs and a lack of breathing apparatus — were involved in the crash that claimed the lives of 17 people.

NDP Leader Lorraine Michael says immediate action is warranted on Wednesday's TSB report on the 2009 Cougar crash. (CBC)

Lorraine Michael, Newfoundland and Labrador's NDP leader, called on government regulators to implement the TSB's recommendations immediately, noting a change in any of those factors could have led to another outcome.

"We were told yesterday unequivocally by the TSB that this accident was preventable," Michael told CBC News Thursday.

"The families hearing that, to know that it was absolutely preventable, has to be extremely upsetting for them. So that's why I think the government has a responsibility now [to] make sure that every recommendation is acted on immediately."

Michael highlighted one of the TSB's four recommendations, that a helicopter's main gearbox should be able to run without oil for 30 minutes. Cougar Flight 491 crashed on March 12, 2009, just 11 minutes after the gearbox lost oil.

"They thought they still had oil," said board chair Wendy Tadros. "They did not know that they'd had a massive loss of oil and that that machine was about to run dry."

Two pilots and 15 offshore oil workers died in the crash, which happened shortly after the Sikorsky S-92A left St. John's to ferry workers to offshore oil installations.

The TSB also recommended that offshore helicopters not fly in rough conditions, that they have emergency breathing equipment capable of working for passengers wearing survival suits, and that each helicopter have a flotation system that can withstand an emergency landing.

The TSB revealed that all of the people on board were still alive when the helicopter crashed on the ocean at high speed, and that all of those who died had drowned. Only one person, Robert Decker, survived the crash.

The TSB poses significant questions for Transport Canada to address, which regulates air travel in Canada, particularly as the board's recommendations extend well beyond Newfoundland and Labrador's offshore oil industry.

In question period Wednesday, National Defence Minister Peter MacKay said Transport Minister Chuck Strahl had directed his officials to respond to the board's recommendations.

In a separate statement, MacKay — who is the federal cabinet representative for Newfoundland and Labrador — said the government would work with the Canada-Newfoundland and Labrador Offshore Petroleum Board "to do all we can to maintain and enhance the safety of Canadian aviation."

The CNLOPB said Wednesday it will review the TSB report first before it comments.