Madan asked in USMA 17165: >Fuel for automobiles and locomotives are >quoted in volume (liters and gallons), how >come the aeroplanes are using mass (tons). > >Is it because the word 'ton' is shorter than >kiloliters or because the oil refineries >deal in tons. > >After all it is easier to measure the volume. >For ex - to measure a tanker truck containing > fuel, one has to find the cubic volume and > apply this formula > 1 cubic meter = 1000 l, > or by using a scale and finding the level. > whereas to find the mass, we should weigh > the truck and subtract the mass of empty truck.
Fuel is loaded by volume but pilots need to know its mass to calculate the plane's total load. A conversion factoris used to find the mass of fuel. The famous "Gimli Glider" was a painful example of a failure of this factor. The first aircraft in the Air Canada fleet to have fully metric documentation was fuelled in Montreal for a flight to Winnipeg. The ground crew applied the formula for conversion of volume to pounds. The captain was unsure, so he asked the ground crew at Ottawa to check the fuel load. They measured the volume with a dip stick, applied the old formula, and reassured the pilot. Near Kenora the engines failed. The co-pilot remembered that there was a wartime airstrip at Gimli. The pilot glided to Gimli and found that it was now a drag strip with a low fence down the middle. He had to land, on top of the fence. The plane was damaged but everyone emerged unbruised. Joseph B.Reid 17 Glebe Road West Toronto M5P 1C8 TEL. 416-486-6071
