The Gimli Glider and the Boeing seven sixty-seven that ran out of gas at forty-one thousand feet

On July 23, 1983, Air Canada Flight 143 — a nearly new Boeing 767 — ran completely out of fuel at 41,000 feet over northwestern Ontario. With 69 souls on board and no engine power, Captain Bob Pearson and First Officer Maurice Quintal glided the aircraft for 17 minutes covering roughly 75 miles, then landed on a decommissioned military runway in Gimli, Manitoba. Everyone survived. The incident became one of the most extraordinary displays of airmanship in commercial aviation history, and the aircraft earned a permanent nickname: the Gimli Glider.

How Did a Brand New Boeing 767 Run Out of Fuel?

The root cause was a unit conversion error compounded by a known maintenance issue. Canada had recently switched to the metric system, and the 767 was Air Canada’s first aircraft to use kilograms for fuel measurement instead of pounds. On Flight 143, the fuel quantity indicators were inoperative due to a fault in the fuel quantity processor. The aircraft had been dispatched under a Minimum Equipment List (MEL) allowance that permitted flight as long as the crew verified fuel quantity manually using a drip stick — essentially a calibrated dipstick lowered into the tank from on top of the wing.

The ground crew in Montreal dipped the tanks and obtained a measurement in centimeters. When they converted that figure, they used the wrong conversion factor — converting liters to pounds instead of liters to kilograms. Since a kilogram is roughly 2.2 times heavier than a pound, they calculated approximately twice as much fuel as was actually on board.

The flight crew reviewed the numbers. Everything appeared correct. But when the initial input is wrong, every downstream calculation is perfectly, consistently, and catastrophically wrong.

What Happened When the Engines Quit?

Flight 143 departed Montreal, stopped in Ottawa, and continued westbound at flight level 410. Somewhere over the remote expanse of northwestern Ontario, the left fuel pressure warning illuminated. Pearson and Quintal initially suspected a fuel pump failure — annoying but manageable. Then the right fuel pressure warning followed. Two simultaneous fuel pump failures on a new aircraft is not a coincidence.

The left engine flamed out first at 41,000 feet. The crew declared an emergency and began diverting toward Winnipeg, starting a drift-down from altitude. Then the right engine quit. At approximately 28,000 feet, Air Canada Flight 143 became a 132-ton glider.

When both engines die on a modern jet, the ambient noise that crews take for granted — systems, air conditioning, pressurization — vanishes. What remains is wind over the fuselage. The 767’s ram air turbine (RAT) deployed automatically, a small windmill extending from the belly that uses airflow to generate minimal hydraulic and electrical power. It kept basic flight controls and a handful of instruments alive. But there was no thrust and no possibility of a go-around.

How Did the Crew Find a Place to Land?

Captain Pearson had an unusual background for an airline pilot: he was a recreational glider pilot who flew sailplanes on weekends. He understood energy management intuitively — that speed is life, altitude is a savings account you can only spend once, and getting slow is fatal.

First Officer Quintal contributed a critical piece of knowledge. He had been stationed at RCAF Gimli, a Royal Canadian Air Force base in Manitoba that had since been decommissioned and turned over to civilian use. He knew it had two long concrete runways, and he calculated it was within gliding distance — roughly 12 miles ahead.

The challenge was enormous. Without engine power, most of the 767’s instruments were dead or degraded. The glass cockpit had gone dark except for emergency displays. The vertical speed indicator was gone. The airspeed indicator was unreliable because the air data computer was receiving only partial power from the RAT. Pearson was hand-flying a swept-wing transport jet on partial instruments, managing a glide ratio for which no training, no manual, and no simulator scenario existed. Boeing and Air Canada had never contemplated total fuel exhaustion on both engines simultaneously.

The Sideslip That Shouldn’t Have Been Possible

As Gimli came into view, the crew faced a counterintuitive problem: they were too high. Overshooting the runway meant landing in scrub brush and highway beyond the field. Without engines, there was no way to steepen the approach with power — the only option was to dump altitude aggressively.

Pearson made a decision found in no 767 training manual. He sideslipped the aircraft — crossing the controls with left rudder and right aileron — to bleed altitude rapidly. Sideslipping a 132-ton transport category jet is something no Boeing checklist covers, but Pearson’s glider experience told him it would work.

What Pearson could now see through the windshield, and what Quintal didn’t know, was that the runway was not deserted. It was a Saturday in July, and the Winnipeg Sports Car Club had set up a drag strip on the main runway. Hundreds of people — families, children on bicycles, cars, and campers — were spending a summer afternoon on what they believed was an abandoned airfield. With no engine noise, there was no audible warning of the approaching aircraft.

The Landing at Gimli

When Pearson put the 767 on the runway, the main gear touched down solidly, but the nose gear failed to lock. The hydraulic system, running on minimal RAT power, couldn’t fully extend it. The nose dropped onto the concrete, and the aircraft decelerated violently — tires blowing, sparks flying, the nose scraping down the runway toward the crowd at the drag strip.

The aircraft stopped 200 feet short of the spectators. The friction from the collapsed nose gear and blown tires actually helped slow the airplane faster than a normal landing roll would have.

No one died. Not a single person on the aircraft or on the ground. Injuries were limited to a few minor cases from the evacuation slides.

Was It Luck or Skill?

The Gimli Glider story invites easy simplification. Luck placed a former military pilot in the right seat who remembered Gimli existed. Luck put the airfield within gliding distance. But skill is what got the aircraft on the ground. Pearson’s glider experience gave him the instincts to manage energy without power. His willingness to sideslip a widebody jet — a maneuver with no precedent — kept them from overshooting the runway. Quintal’s composure in working the navigation problem found them a runway when Winnipeg proved unreachable.

Pearson flew gliders for recreation. That hobby saved 69 lives.

What Happened to the Crew and the Aircraft?

Both Pearson and Quintal were initially disciplined by Air Canada — a decision that drew widespread criticism. Both were later fully exonerated and commended. Pearson received the first-ever Fédération Aéronautique Internationale (FAI) Diploma for Outstanding Airmanship.

The 767 itself was repaired on-site at Gimli, flown out, and returned to regular service. It continued flying for Air Canada for another 25 years before being retired in 2008.

The drag strip at Gimli still operates on the old runway. A small marker near the threshold notes what happened on that Saturday in 1983.

Key Takeaways

• A metric-to-imperial conversion error caused the crew to believe they had roughly twice the fuel actually on board, leading to total fuel exhaustion at cruise altitude.
• The 767’s fuel quantity indicators were inoperative, and the MEL-permitted manual drip-stick method failed to catch the error because the ground crew used the wrong conversion factor.
• Captain Pearson’s recreational glider experience proved decisive — he managed the aircraft’s energy and performed an unprecedented sideslip in a 767 to avoid overshooting the runway.
• First Officer Quintal’s knowledge of the decommissioned Gimli airfield provided a viable landing site when Winnipeg was out of gliding range.
• The incident led to major changes in fuel verification procedures, cross-checking protocols, and metric conversion training across the aviation industry.