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Since the JetA fueler was Pumping JetA from the tanker to the Plane in Gallons.
Jet fuel is 6.25 pounds per gallon. The requirement was to put in 22000 kilograms of fuel, but they put 22000 pounds in instead. They were supposed to have 26 pounds of fuel per mile for a B767 to cover emergencies, but instead they had less 12 pounds per mile. It ran out of fuel with about 700 miles to go.
From a famous incident in the early 1980's there was a notation in paperwork that said (numbers are simplified)
8,000 liters of fuel weighing 14,000 kilograms.
Using only basic comprehension of the metric system (don't look anything up) what can you say about the validity of this statement? What is your reasoning?
If you have 8000 liters of liquid and it weighs 14,000 kg, it's not jet fuel. 8000 liters of water weighs 8000 kg, jet fuel or even avgas would weigh less. So, "Tilt".
I do wonder about that Air Canada incident. Not a pilot myself, but when I start out with a wheeled vehicle, I do at least glance at the fuel level and make a quick mental calculation as to if I have enough "go juice" to get to where I want to go. I realize transport planes don't generally start out with a full load of fuel unless they are on a very long flight, but, still.
It costs fuel ($'s) to have extra fuel. You need to add more fuel (to burn) to carry the weight of the extra fuel.
Also its hard to pull over at the next airport to Get a few extra Pounds or Kilo's of Fuel.
The Fuel gauge on the AC plane were broken, (Actually a circuit board) They did manual Fuel levels of the both wing tanks before they left there start point. The Flight computer keep track of how much they used, to calculate how much more to put on at the stop, That what the told the Fueler,
but it got all confused when they converted the KG to Pounds to Gallons.
If you have 8000 liters of liquid and it weighs 14,000 kg, it's not jet fuel. 8000 liters of water weighs 8000 kg, jet fuel or even avgas would weigh less. So, "Tilt".
Well that is exactly the point. It seems as if the five people who looked at this documentation were lacking in the fundamentals of the "metric system" as taught in grade school. It turns out that 8000 liters of jet fuel weighs about 6400 kg, which requires familiarity with specific gravity of fuel (roughly 80%), but you should know the answer is less than 8000 kg.
It turns out that 8000 liters of vehicle gasoline weighs about 6000 kg. But knowing that vehicle gasoline weighs less than jet fuel qualifies as "mildly technical". But all fuel floats on water (if you have seen movies and TV).
Quote:
Originally Posted by M3 Mitch
I do wonder about that Air Canada incident. Not a pilot myself, but when I start out with a wheeled vehicle, I do at least glance at the fuel level and make a quick mental calculation as to if I have enough "go juice" to get to where I want to go. I realize transport planes don't generally start out with a full load of fuel unless they are on a very long flight, but, still.
Vehicle gasoline is usually about 74% specific gravity at 60 degrees F. So a 60 liter gas tank is contains less than 100 pounds of fuel. Fuel weight is not usually significant in normal land vehicle operations.
The A340 that used to fly from Newark to Singapore (longest commercial flight in the world) filled up it's tank with all 222,000 litres of fuel. As it only had 100 business class seats that is 2220 liters per seat. That is 2220*80% =1776 kg or just under 2 tons of fuel per seat. Even if they didn't burn it all, they still had to carry that much weight. After 9 years they finally gave up and traded the 5 A340 planes back into Airbus (with the promise of buying 5 new A380s starting in 2017). They put 5th freedom stops on their routes. Singapore to LAX now stops in Tokyo, and New York city to Singapore now stops at Frankfurt. The 5th freedom allows them to sell tickets for the intermediate segments. But most importantly it permits them to fly full size three class planes.
Bottom line is I think airlines very rarely use a full tank.
You know, with a gallon to liter conversion SNAFU available and no working fuel gauge, I'm surprised at least one of the pilots didn't go personally supervise fuel loading. I'm sure both of these guys are quite careful about this issue now. Hopefully most will learn from this.
My understanding is that heavy lift cargo pilots are always balancing how much payload they can carry against how much fuel they need to move it so far. They can, of course, carry a ton more cargo if they leave out a ton of fuel, but they just can't carry it as far.
Deceased friend of mine who flew C-124 back in the day said very unusual to have anything like full tanks on takeoff, usually the route was short enough they could make it on less than a full tank.
All major airlines have dispatchers that work out the fuel load......and the responsibility is shared between dispatch and the Captain........normally the Captain signs off on the fuel, pretty much a routine deal. Route, altitude, temp above or below ISA and winds are all done by computer today, even for general aviation. You almost never see an airliner with full fuel, it costs money to haul it around. Jet A weighs 6.7 pounds per gallon for those answering trivia questions.
With gauges inop it is possible to compute the fuel load by using the "drip sticks" built into the wings. It is dreaded by most ops people because it is a little complicated. Basically you have to compute the angle the plane is sitting at and then read a few drip sticks hanging down on each wing........not a fun job. Done it a few times and it works.
With gauges inop it is possible to compute the fuel load by using the "drip sticks" built into the wings.
A dripstick check was done and indicated that there were 7,682 litres already in the tanks. As I understand it, the metric system is taught in the 3rd grade. Basic understanding of the definition of kilogram would let the technician know 7,682 litres of water weighs 7,682 kilograms. Because jet fuel is lighter than water, you would expect the weight of 7,682 litres of jet fuel to weigh less 7,682 kilograms.
But they wrote on the paper that 7,682 litres of jet fuel weighed 13,597 kg.
So there was no problem with the dipstick, it was only a problem of converting liquid volume to weight.
There are fluids that are much denser than water (like freon, Chloroform, citric acid), but techs should know that jet fuels, gasoline, etc are much less dense than water.
Even if they had used the density of water they would have added 15,000 liters of fuel, which would have been short of the 20,000 liters they calculated. But given safety factors they probably would have arrived at their destination running on fumes. But they only added 5,000 liters and they ran out slightly over halfway across Canada.
Location: About 10 miles north of Pittsburgh International
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Quote:
But given safety factors they probably would have arrived at their
destination running on fumes. But they only added 5,000 liters and they ran out
slightly over halfway across Canada.
If you think about it, certainly it was extremely lucky that there was a suitable runway within gliding distance, but if it had worked out as described, and they'd had to hold, or some lengthy vectors, or a go around, they could've run out when they were somewhere low and slow and out of options. Running out at cruise speed and altitude probably gave them a whole lot more chance for a happy outcome.
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