GIMLI GLIDER

Ye Jiadong(29)1A128/2/2011

The Gimli Glider Incident

This incident was a notable crash, however, it did not cause any fatalities as the pilot of a Canadian Boeing 767-200 managedto side slip the plane to safety when it ran out of fuel and both its engines failed.

The plane was on its flight from Montreal to Edmonton and it ran out of fuel at 7920m altitude when it was halfway through its journey. With both its engines , the electronics and the hydraulics systems failing, Captain Robert Bob Pearson and First Officer Maurice Quintal made a quick decision to direct the flight to Winnipeg. However, First officer Maurice Quintal suddenly calculated that they may not make it to Winnipeg as the plane was just too high and descending at a too fast pace. The hydraulics system of the plane was not working so the flaps and the reverse thrust of the engines were unavailable. Thus, the pilots decided to divert again to Gimli which was closer to Winnipeg.

They had two options to land, which was to either make a 360 degree turn to Gimli or side slip. The first option-the 360 degree turn was inapplicable, the aircraft just had too little altitude to do that. Thus, the captain chose the second option-which was to make a sideslip.

Side slipping is a common thing done by glider pilots in order to either lose altitude faster or land quicker. But the Boeing 767 was not a glider! The Air Canada flight 143 was a newly manufactured Boeing 767 and it was one of the first airliners to include an Electronic Flight instrument System which requires the electricity generated by the engines in order to operate. The engines were not working, thus, the aircraft could not operate. So how did it happen?

At about halfway into the flight, the four fuel pumps failed to work as there was no fuel left in the tanks! Without any options left, Pilot Pearson had to use one of his special ways-sideslip to land the plane. This tactic was never heard of in commercial airlines but that was the only way of escaping any injuries.

By executing it, Pearson had to go against the controls which was to turn the rudder one way and the steering wheel another way. Captain Pearson managed to perform it successfully.

So, As the aircraft approached Gimli’s decommissioned runway , Captain Pearson slowly lowered the plant and he slammed on the brakes hard once the plane touched the ground. On its way on the runway, two of the plane’s tires were blown and it slammed into a guardrail. Fortunately, none of the passengers were seriously hurt. There were only minor injuries.

The investigation

The investigation led to a careless mistake by the pilots and the fuel engineers and also a faulty fuel calculator located inside the Boeing 767. But why? It was because fuel loading was miscalculated through misunderstanding of the recently adopted metric system. The Boeing 767 should have been using litres and kilograms instead of gallons and pounds. The trip needed 22300kg of fuel but instead, there was only 22300 pounds of fuel in the aircraft. (10000kg) Also, the fuel quantity indicator system was not functioning, thus, the pilots did not know the amount of fuel in the plane. After another calculation by captain Pearson, he got the same answer as the fuel engineer as he also converted wrongly. Everyone in Air Canada’s fleet had not been given the metric scale training.

The investigation

A litre of jet fuel weighs 0.803 kg, the ground crew and flight crew arrived at an incorrect conversion of 1.77, the weight of a litre of fuel in pounds. This was the conversion factor provided on the refueller's paperwork and which had always been used for the rest of the airline's imperial-calibrated fleet.

There was 7682 litres of fuel already in the fuel tanks. The miscalculation of the ground and flight crew:

7682 litres × 1.77 = 13597 kg

22300 kg − 13597 kg = 8703 kg

8703 kg ÷ 1.77 = 4916 litres of fuel to be transferred

The correct calculation should be:

7682 litres × 0.803 = 6169 kg

22300 kg − 6169 kg = 16131 kg

16131 kg ÷ 0.803 = 20088 litres of fuel to be transferred

Thus, the conclusion is that the ground crew were not skilled enough to use the metric scale and they had converted the amount of fuel needed wrongly and had instead only filed the fuel pumps with half the amount of fuel needed for the flight from Montreal to Edmonton.

My feelings

A slight human error caused such a large scale accident. If The pilot was not an experienced one, the plane would have crashed! How many lives would have been lost? The Gimli Glider incident was really a miracle, the passengers on the plane were extremely lucky to not have suffered any injuries. Of course, although technical problems contributed to the incident, the accident could be averted if the flight crew and the fuel mechanics were better trained in the metric system. Thus, I strongly feel that it was the company’s fault of not training their workers to adapting to the new system.

I personally feel that the metric system would be much better than the imperial system. If the imperial system is not discontinued, the confusion between the two systems will lead to more severe consequences. For example, if a person from Singapore goes to America, which uses the imperial system, he would be very confused when he drives a car there. because, they use mph (miles per hour) instead of kph (kilometres per hour). For the Gimli Glider case, it was a fuel miscalculation which is far more dangerous.

The only country now which is still using the imperial system is America. They feel that it would cost them too much to change the system they use to metric as they have too many road signs, etc around the country. However, I feel that it would only be benefit than deficit for America if they change the system they use to metric. It would also further benefit tourists from other countries.

In conclusion, I feel that the metric system is far better than the imperial system and countries like America should change to the metric system despite the costs involved.

Adapted from: http://en.wikipedia.org/wiki/Gimli_Glider