The Transportation Safety Board blames inexperience and bad weather for a plane crash that killed four people including three passengers and the pilot, in January 2012. 

One man survived.

The Keystone Air Piper PA-31 Navajo plane went down en route from Winnipeg to North Spirit Lake in northwestern Ontario.

TSB spokesman Peter Hildebrand said the plane stalled after ice built up on the wings.

tsb plane crash

Tracy Shead told CBC News last year that her husband, Brian Shead, the lone survivor of the crash, was sitting in the last row of the small plane en route to North Spirit Lake from Winnipeg. (Submitted by Tracy Shead)

He said the pilot had to wait to land while crews cleared snow from the runway.

Hildebrand said the pilot had 2,500 hours of flying time but little experience with winter or remote conditions.

"This particular combination of weather, icing conditions, remote operations at a distance, that's something that's very difficult to train for," he said.

The TSB report revealed the bad weather in North Spirit Lake at the time meant the pilot had to wait in the air for 25 minutes before landing so snow could be cleared from the runway.

In the meantime, ice was building up on the plane until it stalled and crashed.

“The most likely scenario is the flight proceeded normally until the aircraft started to descend,” said Hildebrand. “The pilot had not been in commercial service in an airline before this job. The pilot had not had experience in winter operation conditions.”

Hildebrand said the wording of the manual for the aircraft was also confusing.

Peter Hildebrand of the Transportation Safety Board

Peter Hildebrand of the Transportation Safety Board releases the report into the plane crash Thursday in Winnipeg. (CBC)

"Those were relatively new factors," he said. "So it's a host of things that were new to the pilot's operating situation. However, it must be said that the airline did train that pilot."

The TSB said the aircraft struck the frozen lake surface about two kilometres from the runway.

It was destroyed by the impact and fire that followed.

The agency said since the accident, procedures for using an instrument approach for the North Spirit Lake airport have been upgraded.

The TSB also said Keystone Air Service has made a number of changes since the accident, including staffing two pilots on flights where they rely on instruments, revisions to its operations manual on dealing with icing conditions and amending its record keeping to show required training has taken place.

People in North Spirit Lake are still coming to terms with what happened.

 “Some of them are scared to fly still, but we have no chance that – we have to fly. That’s the only way we can get out of here,” said deputy chief Maggie Kakegamic, who added she hasn't flown with Keystone Air since the crash.

Keystone Air responds

Keystone Air would not grant CBC an interview but a spokesperson who declined to be identified said the company accepts the report.

"We would like to thank the TSB for their work and we are satisfied with the report," he said. "We will continue to work with all industry participants to provide safe, efficient and affordable air travel to Canada's remote communities and throughout North America."

with files from The Canadian Press