Tuesday, July 24, 2012

The Gimli Glider - 29th Anniversary

The Gimli Glider C-GAUN
Twenty-nine years ago today on July 23, 1983, one of the most famous (or infamous) incidents in Canadian aviation history occurred on a routine Air Canada flight from Montreal to Edmonton via Ottawa.  AC 143, a Boeing 767 carrying 61 passengers plus flight crew of eight ran out of fuel over  Red Lake Ontario.

The plane, four months old, the first Air Canada plane to convert fully to metric.  A high tech plane with high tech glitches including a faulty Fuel Quantity Indicator System (FQIS). Failure of the FQIS should have grounded the plane but AC was still writing the procedures manual.  A series of small mistakes led up to the big one.  The decision was made to calculate the necessary fuel load manually.  In times past, this would have been done by a flight engineer but the new planes eliminated that position.

The fuel truck worked in volume but the aircraft people work in weight as they need to keep track of the total weight of the aircraft.  The tanks were dipped and the calculations done and redone, checked and rechecked.  Except they used the  conversion factor of litres of fuel to pounds of fuel instead of the factor to convert o kilograms of fuel.  So when the plane took off they had half enough fuel.  When they stopped in Ottawa they checked everything again, making the same error.

When the plane ran out of fuel, The instrument panel went dead except for a few pre-WWII instruments that were run by an airspeed driven turboprop. The decision was instantly made to divert to Winnipeg.  Captain Bob Pearson was an experienced glider pilot and knew how to fly deadstick.  It was soon obvious they were not going to make it.  It was too far and they were losing speed and altitude too fast.

First Officer Maurice Quintal had served in the RCAF and knew of the abandoned airforce landing strip at Gimli which was closer so they changed course.  As luck would have it, the "abandoned" airstrip had been converted to a racetrack, including go-kart track and that day was "Family Day" so the strip crowded with people and BBQs.

There was enough power from the turboprop generator to get the main landing gear locked into place but not the nose wheel as the slower they went the less power generated.  Braking was at a minimum as the flaps etc could not be deployed but the nose wheel collapsed and the plane ground to a halt without hitting anyone.  No one on the plane was hurt other than a few bumps getting off using the emergency chutes.

While everyone considered the two pilots to be heros, Air Canada tried to pin the blame on them and ground crew. An external independent investigation laid the blame fully on Air Canada's lack of training and lack of procedures, as it should have been. 

Gimli Glider retired to the Mojave Desert
Just as a side note, the A/C crew from Winnipeg that drove up to Gimli to repair the aircraft ran out of gas on their way, but they did get there eventually and in two days had the plane, now known as the Gimli Glider back in the air. She flew another 25 years before being retired to the Mohave Desert in January 2008, with several of the original Gimli crew including Pearson and Quintal on board.

For more detail here are some links:

Wiki has an excellent write up, especially the explanation of the series of errors.

Mojave Skies Blog has a post relating the story as one of the interesting planes at the Mojave Desert site (the picture above is from that post).

Flight Safety Australia has a very detailed article covering both the series of errors and the investigations assessment of Air Canada's responsibility.

And one final blogger:


  1. I never heard this one.
    the Ol'Buzzard

  2. As my relative (a pilot) could tell you trying to land one of those things without power is like trying to land a flying brick. :-)

  3. Funny how small mistakes can turn into big ones. Eastern Airlines almost lost a L-1011 because during maintenance after changing oil in the three engines, new drain plugs were installed. The new drain plugs didn't come with o-rings to seal them and were installed without o-rings. On a flight over the Caribbean all three engines quit. They finally able to start one or more engines(don't remember which) and make an emergency landing. Those o-rings that probably cost pennies almost cost a multi-million dollar aircraft.

  4. Very interesting. I read the stories in the links as well. This is a well known event here but I had forgotten (or never heard) some of the details. The skill of the pilots certainly saved much loss of life. It also is a good illustration that when applying a formula or conversion factor you need to understand the fundamental concepts.

  5. Ol'B, that is your reward for your post on the planes you flew in in the military.

    Demeur, I don't know how they could man-handle that plane with no hydraulic power. It would be worse than a B17.

    Kulkuri, a O-ring cost a space shuttle, did it not? For want of a nail...

    DC, I know. All you need to know is a litre of water weighs 1 kg or 2.2 lbs and common sense would tell you the formula was wrong. But these guys were techs and pilots, not oneof them likely took a science course and certainly not one in metric.

  6. it's really bad how Air Canada behaved with the crew. They not only saved all the passengers but also a multi-million dollar airplane.
    And flying the 767 with no engines like a glider is not something for the average pilot. Even the landing maneuver, with the slide dip, is done on gliders, not commercial airplanes. Like Demeur said before, it's like trying to fly a brick. Cpt Bob Pearson was actually a hero, which everyone recognized except for A/C, trying to cover it's corporate ass.