An optical illusion may have led to the deadly crash of a forest firefighting plane in B.C. two years ago.
The Conair Aviation tanker hit some trees and plunged to the ground near Lytton in July of 2010, killing both pilots aboard.
A report by the Transportation Safety Board says the pilots' depth perception may have been affected by a visual illusion caused by rising terrain beneath the flight path of the aircraft, which was heading in to a ravine along the Fraser River.
Board investigator Glen Friesen says the illusion can lead a pilot to believe he's flying higher than he actually is.
Friesen says when the pilots realized the danger, they dropped their retardent in an apparent bid to to gain some altitude, but the manoeuver failed to avert the crash.
He says Conair has since adjusted its training program to try to address the issue.
