[ Planes ] By Daniel Morley

Remembering the Gimli Glider Incident on Its 35th Anniversary

Today marks the 35th anniversary of one of the most significant and impressive feats in aviation to date. On this day in 1983, Air Canada flight 143 lost power from both engines while 41,000 feet above western Ontario.

In a miraculous feat, the crew was able to successfully perform an emergency landing at a closed Royal Canadian Air Force (RCAF) base in Gimli, Manitoba, with only minor injuries to the 69 persons onboard. Since then, the incident and the airplane have become famously known as the Gimli Glider.

The Story

On July 23, 1983, Air Canada flight 143 was midway through a transcontinental flight from Montreal to Edmonton via Ottawa. The time period was a transitional period for all involved. The aircraft was only four months old, the crew was still new to the fly-by-wire system of the Boeing 767 and Canada was transitioning from the imperial system to the metric system of measurements.

The aircraft was fueled in Montreal with enough fuel to make it to Edmonton but left with an inoperative fuel quantity indication system. The faulty indication showed fuel levels as empty and a misunderstanding led the captain to believe that the flight was safe to fly with the gauges inoperative. In its place, a dipstick measurement was performed in both Montreal and Ottawa, with the data entered into the flight management system.

While over Red Lake, Ontario, an indication was displayed in the cockpit showing low fuel pressure to the left engine. In response, the crew turned off the fuel pump as gravity should have still fed the engines fuel. Minutes later, the same warning came on for the right engine and the crew decided to divert to Winnipeg. Seconds after this warning, the left engine failed.

At this time, the crew declared an emergency, beginning an emergency descent to Winnipeg. Seconds later, as the plane was descending through 35,000 feet, the right engine failed, leaving the multi-million dollar jet basically as a large glider. With no engines, the aircraft was left with no electrical power, meaning the instruments in the cockpit went dark. This situation was unheard of in the airline industry and there was no training for a dual-engine failure in the aircraft.

A Ram Air Turbine (RAT), a small fan for electrical power, was automatically deployed, allowing for the function of the backup instruments as well as the radios. The failure of the engines also meant the loss of hydraulic function. However, the RAT gave limited function to the hydraulic system. With the help of air traffic control, the crew chose to divert to the closed Gimli Air Force Base. Unbeknownst to the crew and air traffic control, however, the main runway at Gimli had been converted to a drag strip for racing.

The lack of engine power and hydraulic power lead to more issues for the crew. As the aircraft neared Gimli for landing, the crew were unable to slow the aircraft using flaps and slats as they were hydraulically powered. The second problem for the crew was the landing gear, which was also hydraulically powered. The backup system for landing gear was to gravity drop the gear. However, this did guarantee the gear would lock down.

As the aircraft lined up to land at Gimli, it was too high and too fast. In response, the captain put the aircraft into a slip, a move common in general aviation, but almost never used on jets. As the aircraft was on short final the crew realized that the runway had been converted into a drag strip. The aircraft touched down on the runway and braked heavily, blowing out all of the tires on the main gear.

The nose gear landed on the guardrail placed for the dragstrip, helping to slow the speeding aircraft down. The plane came to a stop with the nose gear collapsed on the rail and was evacuated with only 10 minor injuries from the evacuation. The entire ordeal lasted for 17 minutes. A small fire broke out in the nose compartment but was quickly put out by attendees of the race strip.

The Aftermath

An investigation found that the engines failed due to fuel starvation, which was attributed to multiple factors. With the change to the metric system, the fuelers in Montreal loaded only half the necessary fuel for the flight to Edmonton.

The pilots failed to find the error and miscommunication lead them to believe that the flight was fine to depart with the fuel gauges inoperative. The final investigation called on Air Canada to implement better training in the new aircraft for ground handlers and pilots, in addition to the airline better allocating the task of the now-defunct flight engineer position in the two-man cockpit.

The investigation did, however, commend the crew and praise them for their skill and professionalism during the event.

The Gimli Glider has become one of the most famous events in aviation. The feats performed by the crew 35 years ago have only been matched a few times since. The aircraft was repaired and re-entered service with Air Canada before being retired in 2008. While the aircraft has since been scrapped, the legacy of the Gimli Glider lives on.