Accident Overview
A scheduled flight from Edmonton to Slave Lake ended in tragedy when the aircraft collided with trees on a ridge one mile south of the lake. The flight departed Edmonton at 1947 local time and climbed to 8,000 feet for the 35-minute trip. The copilot reported over the Slave Lake radio beacon at 2025 local time and advised he would call on final for runway 09.
The Accident Sequence
The pilot was descending northwest of Slave Lake Airport at night in limited visibility. He had apparently completed a timed 180° turn and was homing back to the radio beacon when the aircraft struck trees on a ridge. Weather conditions about 20 minutes before the accident included a precipitation ceiling of 1,000 feet, sky obscured, and visibility of one mile in light snow.
Occupants and Damage
Both pilots were killed and all nine passengers were seriously injured. The aircraft was substantially damaged in the collision.
Official Findings
The investigation identified the following probable causes: The company dispatched the aircraft on a scheduled instrument flight with unserviceable flight instruments; the company did not have adequate maintenance procedures for the aircraft; the pilot attempted to carry out a non-standard instrument approach during weather that was below the approved limits; and Transport Canada inspections and company practices did not ensure adequate standards pertaining to the maintenance and operation of this scheduled air service.