Monday, July 24, 2023

Do you remember the Gimli Glider?

 

40 years ago yesterday, on July 23, 1983, an Air Canada Boeing 767 ran out of fuel in mid-air, following a mix-up over metric versus imperial units of measurement of fuel volume.  The pilots managed to glide as far as a disused military airstrip that was in use that day for amateur drag races, and miraculously managed to land the aircraft without hitting any of the racers or spectators, saving the lives of everyone on board.  The airstrip was named Gimli, in Manitoba province, and the aircraft therefore became famous as the Gimli Glider.

Thirty years after the incident, the pilot and one of the passengers - both of whom had lost their spouses in the interim - met at a reunion event.  They fell in love and got married.  In an article at CBC News, they shared their memories.


Pearl Dion never expected to fall in love with the man who saved her life.

She was one of more than 60 passengers on the famed "Gimli Glider" — the nickname given to the Boeing 767 jet that made an emergency landing near the small community of Gimli, Man., on July 23, 1983, after running out of fuel due to a metric conversion error.

The Montreal-to-Edmonton Air Canada Flight 143 was piloted by Bob Pearson, whose flying skills allowed him to successfully land the plane on an abandoned runway near the town in Manitoba's Interlake region, saving everyone on board — including Dion, now his partner of 10 years.

"Never in a million years did we expect to be together," she told CBC on Saturday, a day before the anniversary of the flight — and her and Pearson's anniversary. "It's something from up above, I guess."


There's more at the link.  It makes for heartwarming reading.

Here's a documentary on the Gimli Glider incident.  Very interesting viewing for aviation buffs - and a warning to be very, very careful about one's units of measurement!




I'm very glad they all survived.  It could so easily have turned into a major disaster.  It's a blessing that Captain Pearson was an experienced glider pilot, and was able to translate that knowledge and experience into gliding an aircraft that was never designed to do so.

Peter


10 comments:

  1. The pilot ran out of gas??? Poor planning...how good a pilot was he??

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  2. Rob,
    There was a conversion problem. The Fuel Totalizer system was out of order. So they had to use dipsticks to measure the fuel that was in the tanks. When they converted from Liters to Kilograms they used the wrong conversion factor. Wikipedia has a very goo analysis on what happened. From Wikipedia.
    "Since the FQIS was not working, Captain Pearson decided to take on enough fuel to reach Edmonton without refueling at Ottawa.[9]: 26  The flight plan showed that 22,300 kilograms (49,200 lb) of fuel were required for the flight from Montreal to Ottawa to Edmonton. A dripstick check found that 7,682 litres (1,690 imp gal; 2,029 US gal) of fuel were already in the tanks. To calculate how much fuel the airplane had to take on, he needed to convert the 7682 litres of fuel already in the tanks to their equivalent mass in kilograms, subtract that figure from the 22,300 kg total fuel that would be needed, and convert that result back into its equivalent volume.[9]: 41  The density in metric units was 0.803 kg/L, so the correct calculation would have been:

    7,682 L × 0.803 kg/L = 6,169 kg = mass of fuel already on board
    22,300 kg − 6,169 kg = 16,131 kg = mass of additional fuel required, or
    16,131 kg ÷ (0.803 kg/L) = 20,088 L = volume of additional fuel required
    At the time of the incident, Canada's aviation sector was in the process of converting from Imperial to metric units. As part of this process, the new 767s being acquired by Air Canada were the first to be calibrated for metric units.[9]: 63–64  The fueler reported that the density of jet fuel at the time was 1.77, which was in lb/L, since other Air Canada aircraft used lb. Pearson and Quintal both used the density of jet fuel in lb/L without converting to kg/L:[9]: 40–41 

    7,682 L × 1.77 lb/L = 13,597 lb = misinterpreted as kilograms of fuel already on board
    22,300 kg − 13,597 kg = 8,703 kg = incorrect mass of additional fuel required
    8,703 kg ÷ (1.77 lb/L) = 4,917 L·kg/lb = misinterpreted as litres of additional fuel required
    Instead of taking on the 20,088 L of additional fuel that they required, they took on only 4,917 L. The use of the incorrect conversion factor led to a total fuel load of only 22,300 lb (10,100 kg) rather than the 49,170 lb (22,300 kg) that were needed. This was less than half of the amount required to reach their destination."

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  3. Also, pilot requested a lower altitude? Height = distance, + fuel mixture gets leaner at higher altitude thus extending range.

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  4. Watch the documentary. The pilot did not screw up. Plenty of other people screwed up, but the flight deck did not.

    Gotta love it when people jump to conclusions based on the headline. Wanna know how we get the politicians we do? The majority of people leap to conclusions based on the headline and skipped right over the buried lede where the truth lies.

    We are doomed.



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  5. Yep, fueling issue... We've encountered that before at NATO bases that do everything in kilograms... sigh

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  6. This was back when I was getting my instrument rating for single engine aircraft from my uncle who was a flight instructor. He would train all of his nieces and nephews for the cost of fuel. The instrument training got put on hold and engine off, dead stick landings on all aircraft I was checked off on happened for a couple of months. That was some hairy shit. I got the hard reality of the true cost of flying after I joined the military and no longer had access to rent aircraft for fuel only. In the AF I was in the Civil Air Patrol and kept current but I had to let the pilots license lapse as it was to rich of a hobby for me. That is one of my biggest regrets letting that license go.

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  7. I watched the hourlong video about this flight. The flight crew deserves only admiration on how they handled the problem. And I'm quite pleased the two got together after all these years. Good story.

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  8. Easy to back-seat pilot, but does the B-767 have no way to manually extend and lock the landing gear? I know the B-727 did. Though as noted in the film, skidding on the nose may have been what actually prevented loss of life.

    And regardless of the mistakes that contributed to the situation, there's no denying that Bob Pearson has mad piloting skills and eggs the size of Cantaloupes.

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  9. I don't have a spare hour to watch the video, but surely planes had fuel gauges like cars back then? I know I have 750km max range from a tank, and if I am using more than expected (say towing a caravan or harder 4WDing than expected), know I can pick up more fuel at certain places along the route.

    I'm not a pilot, so just talking out of my hat, but surely they'd have realised they were low on fuel and wouldn't make the entire journey and could have landed / turned back well before they run out. Don't pilots have to have alternate airfields along their route just in case of say a mechanical failure?

    The mind boggles. Better make the time to watch the video before saying anything more.

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  10. What's truly remarkable is that aircraft was repaired and flew for another 25 years before being retired in 2008. I didn't about Bob and Pearl being a couple, God bless them!

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