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Why do planes measure fuel by weight?
In general aviation, fuel is ordered in gallons. Jet fuel is measured in pounds because the volume of the fuel can change based on temperature, whether it’s Jet A, JP-4, etc. This is especially critical at high altitudes where the temperature will be minus-40 to minus-50 degrees Fahrenheit.
How many Litres is 1 kg of jet fuel?
Thus, one kilogram of Jet A1 will at most range from a volume of 1.333 to 1.176 litres for the S.G. range of 0.75 to 0.85. For an S.G. of 0.79, one kilogram of Jet A1 would be about 1.266 litres.
Why do we use units of volume for aircraft fuel?
Most countries except the USA use metric units for meteorological reports. In theory, fuel should be measured by mass as the amount of thermal energy in one unit of fuel relates directly to its mass. Unfortunately, you cannot weigh fuel when an aircraft is airborne, so the alternative is to measure its volume.
What is the density of jet fuel in pounds per liter?
Typical physical properties for Jet A and Jet A-1
| Jet A-1 | |
|---|---|
| Freezing point | −47 °C (−53 °F) |
| Max adiabatic burn temperature | 2,230 °C (4,050 °F) open air burn temperature: 1,030 °C (1,890 °F) |
| Density at 15 °C (59 °F) | 0.804 kg/L (6.71 lb/US gal) |
| Specific energy | 43.15 MJ/kg (11.99 kWh/kg) |
Why is Jet fuel so expensive?
This fuel is expensive for a number of reasons: The lead itself is expensive. The lead additive means that a refinery must shut down and clean the lead before producing other fuels, this means more refinery time and therefore more costs.
How much does Aircraft fuel weigh?
Unless the specific weight for an item is known, the standard weights used in aircraft weight and balance are as follows: Aviation gasoline 6 lb/gal. Turbine fuel 6.7 lb/gal.
Why do planes have unusable fuel?
Aircraft have a certain amount of unusable fuel because in certain flight attitudes some of the total fuel can become inaccessible, particularly with low fuel levels. Unusable fuel is really a safety mechanism to ensure that the engine is properly fed fuel in all phases of flight.
How much does 1 Litre of jet fuel weigh kg?
0.8 kilograms
As noted above, the volume of a liquid can change, depending on the ambient temperature, so for the conversions noted on the right, a generally accepted average worldwide density of jet fuel of 0.8 is used: If 1 kilogram of water is 1 litre, 0.8 kilograms of jet fuel is 1 litre.
How is aircraft range calculated?
The range can be seen as the cross-country ground speed multiplied by the maximum time in the air. The fuel time limit for powered aircraft is fixed by the fuel load and rate of consumption. When all fuel is consumed, the engines stop and the aircraft will lose its propulsion.
Why do airplanes measure fuel in pounds (kilograms)?
Airplanes measure fuel in pounds (Kilograms) because the weight and balance of the plane are affected by how weight much they are carrying, and how the weight is distributed . Pilots must calculate weight and balance data before the flight to make certain safety margins for weight and balance are proper for the whole flight.
How do you calculate the weight of an airplane?
Pilots need to know the total weight of an airplane (Empty weight + Payload weight + Fuel weight) in each phase of flight to calculate: Measuring fuel load in terms of volume would introduce another calculation (and a potential error) to determine airplane total weight. Airplane weight errors can compromise airplane safety. Google the Gimli Glider.
How does fuel affect the center of gravity of an aircraft?
The weight of the aircraft, and the distribution of the weight and its effect on the CG, therefore is vital to the safety of the aircraft. That is why fuel, a substance which is carried in large quantities, is always measured in weight units. The “moments” given by the distribution of the fuel in different tanks will affect the center of gravity.
What is the fuel efficiency of an aircraft per passenger?
Between 1950 and 2018, efficiency per passenger grew from 0.4 to 8.2 RPK per kg of CO₂. The fuel economy in aircraft is the measure of the transport energy efficiency of aircraft .