A least square estimation technique has been proposed for in-flight fuel estimation for a high
performance combat aircraft. This paper presents the details of least square models for aircraft
fuel estimation, the procedure for building the least square models and their fidelity to estimate
the fuel quantity in the multiple internal fuel tanks of the aircraft from flight data. The
performance of the fuel estimation by least square technique has been verified with 56 different
post flight data with different maneuvers including probe failure cases and compared with
lookup table based estimates, the technique currently being used on the aircraft. Few results
of fuel quantity estimates are presented and discussed. Sensitivity of the least square model
based fuel estimation technique to probe failures has been studied by simulating multiple probe
failures in flight data