Helicopter wreckage, Key Lake, SK. Photo courtesy Transportation Safety Board, Flickr.
The Transportation Safety Board has released its final report into a crash involving a helicopter in January 2015.
The incident happened about 18 kilometres south of Key Lake when the aircraft was being used to string cable between transmission towers.
The pilot completed the first 10 towers of the operation without any problems, but TSB investigator Raymond McNabb said on the eleventh tower there was an unexpected increase in cable tension and seconds later the chopper crashed.
The investigation did not come up with a definitive cause, but there were two things investigators believe could have happened.
“There was approximately 2.7 miles of cable and it is touching the ground, the terrain that helicopter was flying over consisted of rocks and downed tree and debris,” McNabb said.
At some point, it appears the cable snagged on something on the ground or on the tower and that is what brought down the helicopter, he said.
He added there’s really no safe way to train pilots to deal with this type of crash.
“We felt that to teach this type of thing for pilots is impossible to do with a helicopter – dynamic rollover, incipient dynamic rollover – because of the consequences of what could happen.”
Although the helicopter hit a boulder on the ground, the pilot was able to get out and walk away by himself.
McNabb said the pilot was not wearing a shoulder harness and there should have been more observers on the ground.
The type of helicopter involved in this crash is no longer being used for stringing cable operations until further notice.