How Fuel Calculation of Aircraft Works?

From small generators to large commercial vehicles, every machine depends on fuel to function. Having the ability to conduct fuel calculation of an airplane is critical for crews so that they are able to adhere to set routes. There are a few methods and benefits of being able to measure the amount of fuel that is remaining in an aircraft. Quantity of fuel can be measured with the rate in which fuel is flowing into the engine and can be beneficial for the flight crew of an aircraft to calculate the remaining flight time. Airplane fuel meters and measurements also help for comparing the functionality and performance of engines to past calculated performance.

Depending on the type of aircraft, fuel measurement can differ. For aircraft that are smaller and lighter, a mechanical float assembly dictates an indicator and varies the current flow. The mechanical float is a gauge located in the tank that rests on the fuel's surface attached to an indicating rod. As fuel levels drop, the float operates the indicator to display the remaining fuel. While this method is fairly simple, while the plane is in ascent or descent, it can prove unreliable due to displacement of the floater and fuel. The second method is for high-performance aircraft fuel systems in which the quantity of fuel can be measured in electrical capacitance. Electrical capacitance is the ratio of the change in an electrical charge in a system as compared to the change in its electric potential and enables a more accurate system of measuring fuel.

Both systems differ in their operating principle with one depending on the principle of electrical resistance and the other on the principle of capacitance. Transmitters along with receivers and indicators are the two units of the fuel flow measuring system. For transmitters, they are an electromechanical device attached to the fuel system’s delivery side and create an output signal corresponding to the flow rate. Sensors and transmitters are located in tanks and are connected in parallel for getting average values. The sensors are profiled so that they may give linear output to indicate remaining fuel in the tank. For all fuel quantity measurements, indicators are displayed in either pounds or kilograms.