The Canadian Forces fleet of Sea King helicopters is cleared and ready to return to the air after being grounded following a crash at sea last week.

The aging fleet of 27 helicopters,  known as "flying coffins" within the military, was grounded after one of the choppers was ditched while trying to land on the HMCS Athabaskan about 50 kilometres off the east coast of Denmark.

The helicopter struck the deck of the destroyer, then flipped over and landed in the sea upside down.

Two Zodiac rescue boats were dispatched and the crew of five was recovered safely, but the rest of the fleet was temporarily grounded amid safety concerns.

The military announced Monday the grounding had been lifted on the remaining helicopters.

The decision to put the choppers back in the air was based on early research by the military's directorate of flight safety.

"A review of the information we have thus far gives us confidence that we are capable of resuming normal flight operations," said Col. Al Blair in a news release.

The helicopter went down in about 16 metres of water, and was later hoisted onto a barge by salvage tugs and taken to Denmark for investigation, accompanied by the Athabaskan.

Currently, it is sitting on a jetty in Arhus, and is being examined by a six-member team of Canadian flight safety investigators, who arrived in Denmark on Saturday.

The investigators will interview crew members and witnesses and reviewing log books to piece together exactly what took place.

An initial report on the cause of the accident is expected early next week, but it will probably be at least a year before a full report is released.

No results from the investigation have been released yet, and Capt. Dave Devenney, public affairs officer for 8-Wing Shearwater in Nova Scotia,  wouldn't say whether the lifting of the flight ban has anything to do with the findings of the investigation.

Investigators haven't confirmed whether mechanical failure or human error is suspected in the incident.

One former Sea King pilot believes the aircraft are still a solid part of the military's armour because they undergo meticulous maintenance.

"I would venture to say these aircraft are as safe today, if not more so than the day we introduced them. The age of the aircraft is not a factor in accidents," retired colonel Lee Myrhaugen told CTV Atlantic.

The Athabaskan is the commanding vessel of the NATO fleet it is working with. As a result of the accident it is now without its own air support, and it may be some time before the situation changes, even though the ship is scheduled to leave Denmark and rejoin the NATO fleet on Tuesday.

"What we're doing is looking at what we have and looking at all assets and coming up with the proper answer," Devenney said.

In the meantime, several other ships in the multi-national fleet have helicopters that can provide air support to the fleet.

At least 14 Sea Kings have crashed since they were introduced four decades ago. Four of those crashes resulted in fatalities.

Ottawa has ordered 28 Cyclones to replace the Sea Kings, but they aren't expected to be delivered for two more years, with the new helicopters in operation by 2009.

The last of Canada's Sea Kings are expected to retire in 2011.