Our “Looking Back” feature takes us into the past of Aviation. This could be a famous incident, a milestone for aviation or an educational piece to help Simmers.
On Saturday, July 23rd, 1983, things were about to get a lot more exciting at the racetrack/former Royal Canadian Air Force Station Gimli, Manitoba. Due to a fuel calculation error, Air Canada flight 143 ran out of fuel at 12 500m (41 000ft) asl about halfway through its flight from Toronto, Ontario to Edmonton, Alberta.
Image Courtesy of SimBrief
The Alarms Sound
Over Red Lake, Ontario, The aircraft’s cockpit warning system sounded, indicating low/no fuel pressure on the left side of the aircraft. Assuming a fuel pump had failed and the aircraft’s engines could be gravity fed, the pilots turned off the offending fuel pump. There was an electrical fault shown in both the plane’s logs and on the instrument panel indicating that the aircraft’s fuel gauges were inoperative. Because the initial fuel load was incorrectly entered, the flight management computer showed sufficient fuel for the flight; Fuel load was calculated in pounds instead of kilograms by the fuel truck and the flight crew failed to spot the error. Only 45% of the expected fuel was loaded into the aircraft. A few moments after the first alarm, a second sounded for the right engine. As a result, the pilots planned to divert to Winnipeg. Within seconds, they they were forced to prepare for a single-engine landing as the left engine had failed.
The “all engines out” warning sounded as they communicated with controllers in Winnipeg and tried to restart the left engine, A never heard before long bong sounded on the flight deck. Because it was never expected to happen, it was never covered in training, nor practiced in the simulator. The stricken plane lost electrical power moments later and most instruments were rendered inoperative. Without power, the Electronic Flight Instrument System (EFIS), wend dead, only a few emergency flight instruments powered by the aircraft’s battery were functioning. The vertical speed indicator (VSI) was not one. For airliners of this size, The engines supplied power to the hydraulic systems critical to the control of the plane. The automated deployment of a ram air turbine provides this power when the engines are unable to generate the required power.
Landing at Gimli
As the pilots had planned their diversion, they were descending through 11 000m (35 000ft) when the second engine lost power. They searched for ‘flying with both engines out’ in the emergency checklist, but there was no such section. An experienced glider pilot, Captain Pearson was familiar with flying techniques almost never used in commercial flight, making a ‘best guess’ of optimal gliding speed of 220kts (410 km/h; 250 mph) to provide the maximum range and the most options for possible landing sites. During this time, first Officer Maurice Quintal worked on calculating whether they could reach Winnipeg. He used altitude and distance traveled. In 10 nautical miles (19 km; 12 mi) the aircraft lost 5,000 feet (1,500 m), giving a glide ratio of approximately 12:1.
Quintal proposed landing at the former RCAF Station Gimli, a now closed air force base where he had once been stationed. Neither Quintal nor the ATC knew that a part of the facility had been converted to a race track complex, Gimli Motorsports Park. A race was underway that Saturday and that area was full of vehicles. Also, a portion of the decommissioned runway was being used as a drag race track.
The pilots used a ‘gravity drop’, lowering the landing gear and hopefully locking it into place. While main gear locked, the nose wheel failed, which was later found to be advantageous. The aircraft became increasingly difficult to control as it slowed on approach to landing, because the ram air turbine generated less power. As the runway drew near, it became apparent that the aircraft was coming in too high and fast, raising the danger of running off the runway before it could be stopped. With very limited options, Pearson decided to execute a forward slip to increase drag and lose altitude, a manoeuvre commonly used with gliders and light aircraft to descend more quickly without increasing speed. Without engines, the plane made virtually no noise during its approach and people on the ground had no warning of the emergency landing. As they approached the raceway/runway, the pilots noticed that there were two boys riding bicycles within 1,000 feet (300 m) of projected touchdown. Later, Captain Pearson stated that the boys were so close that he could see the terror on their faces as they realized that a commercial airliner was about to land where they rode.
The failure of the front landing gear to lock into position during the gravity drop, and a guardrail installed along the centre of the runway averted a potential disaster. Pearson braked hard as the craft touched down, blowing two of the aircraft’s tires. The nose wheel collapsed back into its well, causing the nose to slam into and scrape along the ground. The additional friction slowed the airplane and stopped an incursion into the crowd surrounding the runway. Air Canada flight 143 came to a final stop on the ground 17 minutes after running out of fuel.
Among the 61 passengers and still more on the ground, there were no serious injuries. A minor fire in the nose area was extinguished by people armed with fire extinguishers. As the tail was elevated, there were some minor injuries when passengers exited the aircraft via the rear slides, which were not long enough to accommodate the increased height.
Thanks to quick thinking and acting on behalf of both pilots, a much bigger catastrophe was avoided.