The Transportation Safety Board of Canada said Friday it will make every effort to recover a helicopter that crashed this week off Newfoundland's east coast.

About 20 personnel have been assigned to the case, including specialists from the U.S. as well as an expert in underwater recovery, lead investigator Mike Cunningham said at a briefing with reporters.

The Cougar Helicopters chopper crashed Thursday morning in the Atlantic Ocean, minutes after sending a mayday signal and reporting mechanical problems.

Cunningham said the recovery team — which includes members who worked on the 1998 Swissair disaster, in which a jet crashed near Peggys Cove, N.S. — will work quickly.

He said some people will start the work as early as Friday night.

The effort will require some careful manoeuvres, involving a team that will deploy two remote-operated vehicles.

"You have to imagine that this aircraft is full of water now. It's quite heavy and it's not designed to be lifted full of water. It's designed to fly through the air," Cunningham told reporters.

"We have to do this in such a way that we can ensure that we do it properly," he said.

If everything goes well, he said, the team might be able to bring up the helicopter, a Sikorsky S-92, in as little as one week.

Search and rescue authorities believe the helicopter is under about 120 metres of water.

The chopper had been carrying 18 people, including two crew members from Cougar Helicopters and passengers who were being ferried to platforms at the Hibernia and White Rose oilfields.

One person was plucked alive from the ocean while searchers recovered one body on Thursday. To date, searchers have been unable to find any signs of the 16 missing passengers.