Air Canada Flight 143 was a Canadian scheduled domestic passenger flight between Montreal and Edmonton that ran out of fuel on July 23, 1983, at an altitude of , midway through the flight. The flight crew successfully glided the Boeing 767 to an emergency landing at a former Royal Canadian Air Force base in Gimli, Manitoba that had been converted to a motor racing track. This unusual aviation incident earned the aircraft the nickname "Gimli Glider". The accident is commonly blamed on mistaking pounds for kilograms, which resulted in the aircraft carrying only 45% of its required fuel load. However, the units error was the last in a series of failures that aligned in a Swiss cheese model to cause the accident.