Through the Mountains
He departed the Calgary area late in the afternoon on a VFR flight to the West Coast. However, the planned six-hour flight ended tragically less than an hour later when he mistakenly followed the wrong fork in the river and turned into a narrow box canyon.
Surrounded by 9000-ft. mountains, he could neither outclimb the terrain nor turn around. As he strained for altitude, the classic stall/spin occurred, with no altitude or room to recover. Neither he nor his passenger survived.
Weather did not bring about this accident, as it was a clear and sunny afternoon with light winds; nor was a lack of mountain-flying experience to blame, as the Cessna 150 pilot had flown the routes in the Rocky Mountains on numerous occasions.
Three factors may have led to the accident: vision, available charts and altitude.
First, the pilot was classified as having monocular vision (one good eye), and he was looking directly into the afternoon sun. Depth perception and map reading would have been difficult even without his visual handicap.
Second, the only map of the accident area recovered from the crash site was a 1:1,000,000 scale chart. World Aeronautical Charts show little detail of the valleys and passes in the mountains, and so it would have been easy to mistake the turn along the south branch of the river for that of the main river 3 mi. farther on.
Third, the pilot had flight-planned an altitude of 9000 ft., but evidently had not climbed to that altitude: the accident site was at the 6300-ft. level.
Originally Published: ASL 4/1997
Original Article: Through the Mountains