Fatigue and a lack of training contributed to a fiery plane crash that killed seven people in Halifax two years ago, but the full story will never be known, investigators say.

The Transportation Safety Board released its final report Thursday into the crash of the cargo-laden MK Airlines jet.

Investigators were unable to retrieve information from the cockpit voice recorder aboard the crashed MK Airlines jet.
Investigators were unable to retrieve information from the cockpit voice recorder aboard the crashed MK Airlines jet.
(TSB)
All seven crew members aboard the plane were killed when it crashed on takeoff at the Halifax International Airport early in the morning on Oct. 14, 2004.

The Boeing 747 had arrived in Halifax from Connecticut to pick up a load of seafood and refuel before heading to Zaragosa, Spain.

But the plane — loaded with lobster, lawn tractors and computer gear — failed to gain enough speed as it taxied down the runway. The tail of the aircraft hit a berm, sending the plane crashing through the woods.

The cargo jet exploded in a quarry across the old Guysborough Road.

Flight recorder destroyed

The flight voice recorder was destroyed in the fire, TSB investigators said, so they'll never know exactly what happened.

However, they have determined that crew members had been awake for 20 hours at the time of takeoff, and that fatigue likely contributed to errors in entering cargo weight on a flight computer.

The investigation also found that crew members had not been formally trained on the software.

The crew didn't notice the error, investigators say, so with the calculations below the true weight by tens of thousands of kilograms, the plane was unable to take off.

"By putting the message out within the report and the findings about how fatigue can affect behaviour and influence crew actions, we feel … we've dealt with it adequately by highlighting it in the findings," TSB investigator Bill Fowler said.

Investigators are recommending that aviation regulators in Canada, the United States and Europe require transport planes to carry a device that would alert pilots when there's insufficient thrust to become airborne.

In a statement, MK Airlines said without the voice recorder, the TSB findings couldn't be called conclusive.

Family members of the victims have filed a civil lawsuit against the airline, which is managed from England but registered in Ghana.