In 1983 Canada was in the midst of switching from using imperial to metric units. As can be imagined, this had an effect on Canadian airlines (as well as almost every other industry in the country), especially since they were flying planes manufactured in the United States of America, a country which stands out as the rebel nation that refuses to use the same standard as the rest of the world. This change in unitary measurement contributed to one of the largest “math mistakes in history.”
July 22, 1983 is a day Captain Robert Pearson and First Officer Maurice Quintal will never forget, and neither will many Canadians who were alive at the time. These pilots were set to fly a Boeing 767 jet from Montreal to Edmonton for Air Canada, Flight 143 that morning. When they arrived at the airport they were informed that the aircraft’s fuel gauges weren’t functioning due to a fault in the Fuel Quantity Indicator System (FQIS), and the part needed for repairs would not be delivered until later that day. Instead of postponing the flight, Captain Pearson had the engineers manually check the fuel levels (multiple times) of the aircraft before taking off.
Flight 143 took off on time; however, about half-way through their flight and at 41,000 feet, the fuel pressure alarm for the left engine went off. The aircraft was four-months old with fairly new electronic technology in it and, since they had checked the fuel levels a few times before taking off, they opted to shut off the alarm, believing it was just a glitch and that even if something was wrong gravity should be able to feed fuel to both engines. A few moments later the fuel pressure alarm for the right engine went off, and then they knew something was wrong. They diverted to Winnipeg for an emergency landing.
Unfortunately, the right engine went out at 35,000 feet. Since the airplane’s generators and hydraulic system required at least one engine to function properly in order to work, their entire system shut down. There was no electricity being generated to run the computer, and there was no power to manipulate the ailerons, rudder, or elevator. At this point Captain Pearson and First Officer Quintal decided to consult their emergency checklist, but much to their dismay there was nothing included in it about how to make an unpowered landing; nothing to tell them what to do in a situation where both engines stopped functioning.
Quintal knew of an air force base nearby in Gimli, Manitoba and they decided to divert there, but neither pilot was aware that it had since been converted into a racing complex. That day the Winnipeg Sports Car Club was holding races on one of the former landing strips. Luckily, when the spectators noticed a Boeing 767 jet hurtling down towards them they had the good sense to get out of the way. In fact, the good people of the Winnipeg Sports Car Club even helped extinguish the friction fire that started in the nose of the plane when it landed.
Captain Pearson, it turns out, was experienced at towing and flying glide planes, so when they began to come down he executed a forward slip, essentially cutting the drag and their speed before they touched down. They debated pulling a 360-degree turn to decrease their speed, but didn’t have enough altitude to do so safely. When they touched down, they hit the brakes hard and blew out two of the plane’s tires. The nose wheel collapsed and was forced back into its well; the aircraft’s nose slammed into and then scraped along the ground, further helping slow down the plane.
There were 61 passengers and 8 crewmembers on Flight 143, and the most severe injuries were minimal. No one at the racing event was hurt, though many were probably a little freaked out. The metric system had taken down the plane; when they converted the fuel from pounds to kilograms, they had miscalculated. They put less than half of the fuel required for the flight into the plane: they filled it with 10,100 kilograms instead of 22,300.
Even though Captain Pearson and First Officer Quintal landed the plane as safely as they possibly could given the circumstances, Captain Pearson was demoted for six months and First Officer Quintal was suspended for two weeks, along with three of the maintenance workers who had given the plane the OK to fly. There were several attempts made at a simulator in Vancouver to recreate the crash and have crews land the plane safely, but the results were much more disastrous than what happened at Gimli.
The aircraft was taken to a maintenance base in Winnipeg after the crash, repaired, and enjoyed another 25 years of service. Captain Pearson and First Officer Quintal were eventually assigned as crewmembers aboard another Air Canada flight, one that turned out to be the same plane they had successfully landed in Gimli. The obvious jokes were made between the two of them. The plane was retired on January 1, 2008.
The entire situation is almost a comedy of errors, from the metric conversion to the new aircraft with new and unfamiliar technology, to landing on what they believed was still an air force base but in actuality had turned into a race track. But, all told, the “Gimli Glider” was “a nearly perfect demonstration of dead-stick flying, accompanied by an extra-large portion of good fortune.”
– Leah Harrower, JETPUBS Inc.
http://www.damninteresting.com/the-gimli-glider/
https://threesixty360.wordpress.com/2008/02/09/math-mistakes-in-history-the-gimli-glider/
http://globe.erau.edu/throwback-thursday-the-gimli-glider-lands-in-1983/