Investigation Summary
The flight departed Vancouver at 07:02 PDT under instrument flight rules. Approximately six minutes later, while climbing through 2,400 meters, the aircraft entered a sudden and extremely steep descent. Radar data indicated the aircraft was falling at a rate consistent with uncontrolled flight, losing 1,500 meters of altitude in under 60 seconds. The wreckage was found in rugged, heavily wooded terrain near Crown Mountain, with the main fuselage located at an elevation of approximately 900 meters. The lack of ground scars or significant tree damage at the site suggested a near-vertical impact following a structural failure in flight. The investigation was significantly hampered by the absence of a cockpit voice recorder (CVR) and flight data recorder (FDR), which were not required by Canadian regulations for this aircraft type and operation at the time. The discovery of significant alcohol impairment in the captain raised serious concerns regarding pilot incapacitation or impaired judgment, though the exact sequence of cockpit events remains unknown.
Final Conclusions
The Transportation Safety Board of Canada (TSB) concluded that the aircraft underwent an in-flight breakup due to aerodynamic speeds exceeding structural limits during a rapid descent. The investigation identified the captain's severe alcohol impairment (0.24% BAC) as a significant factor, although it could not be proven that this led directly to the descent. The TSB also noted that the lack of onboard flight recorders prevented a full understanding of the circumstances leading to the loss of control.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Emergency Locating Transmitter (ELT)
A device designed to transmit a distress signal upon impact; in this case, it activated but no signal was successfully sent or received.
Flight Recorders (CVR/FDR)
The aircraft was not equipped with these systems as they were not legally mandated for this class of cargo aircraft in Canada at the time.
Interesting Facts
- 01The aircraft was manufactured in 1977, serial number TC-235, and had previously been registered as N235BA.
- 02The captain's blood alcohol level was 0.24 percent, three times the legal limit for driving.
- 03Post-mortem examination of the captain identified focal severe coronary artery atherosclerosis and liver steatosis, suggesting chronic excessive alcohol consumption.
- 04The aircraft was not equipped with a cockpit voice recorder or a flight data recorder, as they were not required for this aircraft type.
- 05The emergency locating transmitter (ELT) activated but the antenna was damaged, preventing a signal from being received by satellites.
- 06The descent rate exceeded 30,000 feet per minute, causing the aircraft to break up before impacting the terrain.
Safety Actions & Advisories
Substance Abuse Program Requirements
Source ↗The TSB issued Recommendation A17-02, urging Transport Canada to develop and implement requirements for a comprehensive substance abuse program, including drug and alcohol testing, for persons in safety-sensitive positions.
Flight Recorder Mandates
Source ↗The TSB reiterated the need for lightweight flight recording systems on aircraft not currently required to carry them to facilitate accident investigations.
Location
ACCIDENT SITE · Coordinates taken from the entered by an editor.