Investigation Summary
The flight originated in Athens and traveled through Tenerife, Santa Maria, and Moncton before reaching Toronto. A relief crew took over in Moncton due to duty time concerns for the original crew, but the relief crew themselves failed to obtain sufficient sleep before the final legs. In Toronto, the aircraft was configured with cattle pens and loaded with 86 head of livestock and two cattle handlers. During the flight to Edmonton, the crew reported a failure of the #4 generator. Investigators noted that an interruption to the essential electrical system, potentially involving the #1 generator as well, may have further distracted the captain from his monitoring duties at a critical stage. The approach was conducted without glideslope guidance (back-course ILS) in poor weather conditions including blowing snow and turbulence. The first officer was undergoing his final check ride for certification. Although he had 1,200 hours on type, he had just been promoted to Boeing 707 operations and lacked recent experience, as this was his first flight following a six-week holiday. Investigators believe the combination of fatigue and lack of recent experience led to a loss of situational awareness. Although the captain attempted to arrest the sink rate in the final seconds, the aircraft struck poplar trees and power lines before slamming into a ridge in a gravel pit. The cockpit and forward fuselage separated, and the cargo was ejected forward up to 100 meters from the impact site.
Final Conclusions
The investigation concluded that the accident was a Controlled Flight Into Terrain (CFIT) caused by the crew's failure to maintain a safe altitude during a difficult instrument approach. Contributing factors included severe crew fatigue, the first officer's lack of recent experience and overall inexperience on the Boeing 707, and the potential distraction caused by a generator failure. The investigation also noted that the Flight Data Recorder (FDR) had ceased functioning a week prior to the accident, and the Cockpit Voice Recorder (CVR) was too badly damaged by fire to provide data.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
53-year-old male, 19 years with the airline.
First Officer
27-year-old male, first flight in 6 weeks, final check ride.
Systems & Failure Modes
Electrical System / Generators
A failure of the #4 generator was reported; investigators also considered an interruption to the essential electrical system as a primary distraction for the crew during the approach.
Back-course ILS
A non-precision approach using the localizer signal from the opposite end of the runway, which does not provide vertical glideslope guidance.
Flight Data Recorder (FDR)
The device was recovered but found to have ceased recording data a week before the crash.
Interesting Facts
- 01The aircraft was 8 years old at the time of the accident (MSN 18826/389), having been manufactured in 1964.
- 02The aircraft was carrying 86 cattle, all of which were killed in the crash.
- 03The First Officer was on his first flight in six weeks and it was his final check ride for certification.
- 04The Flight Data Recorder had not been recording for approximately one week prior to the accident.
- 05The aircraft struck the ground in a nose-up attitude with landing gear down and locked.
- 06The engines were estimated to be running at 90% power at the time of impact, suggesting a late attempt at a go-around.
Safety Actions & Advisories
Fatigue Management
The investigation highlighted the critical danger of crew fatigue, leading to increased scrutiny of relief crew rest requirements and duty time regulations.