What happened
On a scheduled international service from Spokane, Washington, to Calgary, Alberta, via Cranbrook, British Columbia, West Coast Airlines Flight 794 was conducting its arrival sequence at Calgary. At approximately 23:33 hours, the aircraft reported being at 17,000 feet. Following instructions from Calgary Terminal Control, the flight descended to 13,000 feet and proceeded toward the Calgary VOR station.
As the aircraft approached the airport, controllers provided radar vectors to guide the plane toward the localizer for runway 28. The crew accepted these vectors and was subsequently cleared for a straight-in approach. Throughout the descent and approach, air traffic control provided updates regarding the aircraft's position relative to the localizer and the outer marker intersection. At 23:52 hours, after passing over the outer marker, the flight contacted the control tower and received clearance to land on runway 28.
Shortly after this final communication, the aircraft impacted the terrain approximately 8,000 feet before reaching the runway threshold, landing 420 feet to the right of the centerline. The impact occurred while the plane was in a 5-degree nose-down attitude, causing it to slide roughly 800 feet before stopping. The accident resulted in 4 slight injuries and left 11 passengers and crew members unharmed. The aircraft was a total loss.
Findings
The investigation determined that the primary cause of the accident was the pilot in command's failure to adhere to the required minimum altitude during the approach phase. Additionally, the lack of monitoring by the co-pilot during the final stages of the descent was identified as a contributing factor.