Investigation Summary
The incident was rooted in the transition to the metric system in Canada. The Boeing 767 was Air Canada's first aircraft to use metric fuel measurements (kilograms), while the rest of the fleet used pounds. The aircraft was operating under a Minimum Equipment List (MEL) relief that allowed flight with one FQIS channel inoperative, provided manual drip calculations were performed to verify fuel quantity. Due to a faulty Fuel Quantity Indicator System (FQIS) where both channels were eventually disabled by maintenance confusion, the ground crew and pilots performed manual calculations using a drip tube. A technician had tagged the circuit breaker as 'inoperative' and noted the issue in the logbook, but subsequent confusion led to both channels being disabled. They used a conversion factor of 1.77 (lb/L) instead of 0.8 (kg/L), leading them to believe they had 22,300 kg of fuel when they actually had only 22,300 lbs (roughly 10,115 kg). This was less than half the fuel required for the flight. Beyond the calculation error, the Lockwood Report (the official Board of Inquiry) found that Air Canada had neglected to clearly assign responsibility for fuel load calculations in abnormal situations. This task had historically belonged to flight engineers, but Air Canada failed to reallocate the duty after transitioning to the two-crew cockpit of the 767.
Final Conclusions
The primary cause was a human error in fuel calculation compounded by maintenance procedures that allowed the aircraft to fly with a known faulty fuel gauge system. The successful outcome was attributed to the exceptional gliding skills of Captain Robert Pearson and First Officer Maurice Quintal.
Video Analysis
The Gimli Glider: Air Canada Flight 143 — A detailed look at how a Boeing 767 ran out of fuel mid-flight and the incredible dead-stick landing that followed.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Robert (Bob) Pearson. An experienced glider pilot, which proved critical during the descent.
First Officer
Maurice Quintal. Had previously been stationed at RCAF Station Gimli, providing vital local knowledge of the runway.
Systems & Failure Modes
FQIS
Fuel Quantity Indicator System; it was malfunctioning, necessitating manual fuel calculations.
RAT
Ram Air Turbine; a small propeller that deploys to provide emergency hydraulic pressure when engines fail.
Dripstick
A manual tool used to measure the fuel level in the tanks from beneath the wing.
Interesting Facts
- 01The aircraft was the first in Air Canada's fleet to use the metric system for fuel.
- 02The crew calculated they had 22,300 kg of fuel, but they actually had 22,300 lbs.
- 03The Boeing 767 has a glide ratio of approximately 12:1.
- 04The nose gear did not lock and collapsed upon landing, which actually helped stop the plane.
- 05There were no fatalities, but 10 passengers were injured during the emergency evacuation via the rear slides.
- 06The Board of Inquiry found Air Canada failed to specifically assign fuel calculation responsibility after removing flight engineers.
- 07The aircraft became famously known as the 'Gimli Glider' following the incident.
Safety Actions & Advisories
Standardization of Units
Air Canada and other operators standardized training and procedures to prevent the mixing of metric and imperial units during fuel loading.
FQIS Maintenance Procedures
Revised maintenance protocols were established to ensure aircraft do not fly with critical fuel gauging systems disabled without redundant verification.
Location
APPROXIMATE AREA ONLY · This position predates coordinate provenance tracking. Treat it as an approximate marker for the area, not the accident site. No map is shown, because a marker here would imply a precision the record does not have.
Reported location: Gimli, Manitoba, Canada