Patent ID: 8371533

Claim:
A method of aircraft operation, comprising the steps of: (a) providing one or more main fuel tanks in which fuel is stored, said one or more main fuel tanks being provided with one or more fuel gauges arranged to provide a measure of the amount of fuel in said one or more main fuel tanks, (b) providing one or more auxiliary fuel tanks in which fuel is stored, (c) the aircraft using fuel during a first phase of fuel consumption, said one or more auxiliary fuel tanks holding fuel upon commencement of the first phase, and said one or more auxiliary fuel tanks being substantially empty of fuel immediately after the first phase, (d) during the first phase of fuel consumption, providing an indication of the amount of fuel carried by the aircraft by means of summing (i) the amount of fuel in said one or more main fuel tanks as measured by said one or more fuel gauges and (ii) the amount of fuel remaining in said one or more auxiliary fuel tanks as calculated using a measure relating to the fuel consumption rate, wherein during the first phase fuel is pumped from the one or more auxiliary fuel tanks to the one or more main fuel tanks to maintain the quantity of fuel in the one or more main fuel tanks at a particular level, (e) the aircraft using fuel during a second phase of fuel consumption, the second phase commencing immediately after the end of the first phase, said one or more auxiliary fuel tanks remaining substantially empty of fuel during the second phase of fuel consumption, and (f) during the second phase of fuel consumption, providing an indication of the amount of fuel carried by the aircraft, the indication being based on the amount of fuel measured by said one or more fuel gauges.