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Gimli Glider

The Gimli Glider is the name given to a famous incident in aviation history, on July 23, 1983, when a Boeing 767, Air Canada Flight 143, ran out of fuel at 40,000 feet over northern Canada and had to make a gliding landing at a former airbase at Gimli, Manitoba.

The story starts in a somewhat amusing fashion, an argument over metric conversion. Normally a 767 if fueled almost completely automatically using a device known as the Fuel Quantity Information System Processor, which runs all of the internal pumps and reports to the pilots on the status of the fuel load. However Flight 143's FQIS was not working, later traced to a bad solder joint, so the fuel quantity had to be estimated with a dripstick[?], a sort of dipstick for planes. After trying three times and coming up with the same number, Flight 143 flew the short distance from Montreal to Ottawa. On landing they had the tanks re-dripped just to make sure. Once again the numbers added up.

But they didn't. The 767 measured fuel in kilograms, whereas all of the manuals and other planes in the Air Canada fleet used pounds[?]. Looking in their notes for the conversion they used the factor of 1.77 pounds/liter, but a plane measured in kg should have used .8 kg/liter instead. After using the 1.77 figure they punched in 20,400 to the computer, indicating kg, and the computer said there was enough fuel. In fact they had only 9144 kg onboard, not nearly enough for their flight to Edmonton.

At 41,000 feet over Red Lake Ontario the cockpit warning system chimed four times, and indicated a fuel pressure problem on the left side. The pilots thought a fuel pump had failed, and turned it off. The computer said there was still lots of fuel, but of course it didn't really know. A few moments later a second alarm sounded, and the pilots decided to divert to Winnipeg. Within seconds the left engine failed and they prepared for a one-engine landing.

While they attempted to re-start the engine and communicate with controllers in Winnipeg for an emergency landing, the warning system sounded again, this time with a long "bong" that no one had ever heard in the simulator, the sound for "all engines out". Seconds later the right side engine stopped, and the 767 was a glider, and the cockpit voice recorder could easily pick out the "oh f*uc".

The 767 is a highly advanced aircraft which uses a "glass cockpit". Instead of mechanical instruments, which are hard to read and fail regularly, the instrumentation is computerized and presented on several monitors in the cockpit. This works very well with the exception that the jet engines also deliver electical power to the aircraft, and most of the cockpit suddenly went dead. One of the dead instruments included a vertical-rate indicator, which would let them know how far they would go.

The engines also supply power to the hydraulic systems, without which a plane the size of the 767 could not be controlled. However Boeing actually planned for this and included a device known as a ram air turbine automaticaly popped open on the side of the plane, spinning a propeller to provide enough power to the hydraulics to make it controllable.

The pilots immediately opened the emergency guide to the section on flying the aircraft with both engines out, only to find there was no such section. Pearson glided the plane at 220 knots, his best guess as to the optimum airspeed. Copilot Quintal began making calculations to see if they'd reach Winnipeg, the plane had lost 5,000 ft in ten nautical miles (15 km), giving a glide ratio of approximately 11:1 (which is actually quite good). Air traffic controllers and Quintal both calculated that Winnipeg too far.

At this point Quintal selected his former RCAF base at Gimli as the landing spot. Unbeknownst to Quintal, since being in the service Gimli had "gone public" and was now being used for drag racing, and to make matters worse, on this particular day the area was covered with cars and campers for "Family Day".

Quintal did a "gravity drop" of the main gear, but the nose wheel, which opens to the front, wouldn't lock. The ever reducing speed of the plane also reduced the effectiveness of the ram air turbine, and the plane became increasingly hard to control. Nevertheless they made the runway, and as soon as the wheels touched they stood on the breaks. The plane came to rest, nose down, only a few hundred feet from Family Day at the end of the runway.

No one was hurt, although there were minor injuries when exiting via the rear slide, which, at the tail, was almost vertical. Mechanics soon repaired the minor damage and flew the plane out two days later. Within weeks it was fully repaired and back in service.

As an amusing side note, the mechanics sent from Winnipeg Airport ran out of fuel on their way to Gimli, and found themselves stranded in the backwoods of Manitoba. Another van was sent to pick them up.

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