VANCOUVER - If the float plane that crashed and sank off Saturna Island, B.C., had been equipped with doors that ejected, some of the six people killed may have survived.

The recommendation has been made by the Transportation Safety Board at least twice in the past, but no changes have been made.

Instead, the TSB's Bill Yearwood said passengers in December's crash were trapped when the doors were jammed shut as the plane sank to the bottom of the harbour near the Gulf Island off the B.C. West coast.

"Seaplanes may not be optimally designed to allow easy occupant escape while under water," Yearwood concluded as he released some preliminary findings on the crash Thursday.

Transport Canada, the body that implements TSB recommendations, has known about door problems on float planes for several years.

A safety board report on the death of two float-plane passengers in the Northwest Territories in 2004 spoke of the passengers surviving the crash, only to die in the submerged cabin because they couldn't get out.

In the follow-up safety action taken after the crash, Transport Canada said the suggestion of jettisonable doors or pop-out windows was the jurisdiction of the plane manufacturer and that the department "will not take any action relating to the issue."

But on Thursday, when asked if the door issue was a serious problem, Yearwood replied: "Yes. We have loss of life and we have jammed doors."

Four of the six people taken from the submerged plane had removed their seatbelts. An infant that died was being held by her mother and one man was found still strapped to his seat.

Yearwood said when the plane slammed into the water, the impact twisted the frame, popping open two doors but firmly jamming the other two.

The pilot and another passenger escaped from their closest doors. Both were rescued and have only recently been released from hospital.

But the other passengers entered into the left-hand door of the Seair de Havilland Beaver, and Yearwood said it's not uncommon for passengers to want to exit out of the door they came in, not any door that opens.

The open doors would have been just a few metres away, but Yearwood said it would have been dark and the plane would probably have been tilted.

"I know from personal experience being in a sinking aircraft that you get disoriented very quickly."

The preliminary TSB evaluation shows the plane was leaving Lyall Harbour with gusting and variable winds at the time. The pilot attempted to takeoff to the northwest, then turned around and tried to take off while heading into the harbour.

The two survivors were rescued within minutes, but the plane sank almost immediately and divers later found the remaining six bodies inside the wreckage.

Yearwood said investigators haven't determined yet what caused the crash.

He said investigators will conduct tests flights to try to replicate what may have caused the crash and will be going over other reports on similar accidents.

"This investigation has focused the TSB's attention on a number of issues regarding jettisonable or push-out emergency exits on seaplanes, underwater egress training for crew, pilot training for flight in mountainous areas, aircraft handling characteristics and the wearing of personal flotation devices."

An investigative series done by The Canadian Press last August found that Transport Canada wouldn't make safety changes, despite numerous reports that said lives could be saved if planes were equipped with ejectable doors and float plane passengers wore life jackets.

Virgil Moshansky, the judge whose inquiry into the 1989 Dryden air crash brought major changes to the industry, said there's a lot of costs involved in forcing manufactures to make design changes such as doors or windows that eject.

He said plane makers put pressure on the federal government.

"Unfortunately it takes accidents and deaths for Transport (Canada) to react in time," he said Thursday.

A spokesman for Transport Canada was unavailable for comment.