Abstract: A process for periodically calibrating an algorithm in a control unit of a system for balancing loads on a thrust bearing of a gas turbine engine rotor is disclosed involving the steps of initializing a calibration of the control unit algorithm, causing the engine to attain a crossover condition, measuring the residual load on the rotor thrust bearing, calculating a residual load on the rotor thrust bearing by means of the control unit algorithm, comparing the measured residual load and the calculated residual load on the rotor thrust bearing to determine a difference therebetween, and modifying the control unit algorithm to compensate for the difference between the measured and calculated residual loads on the rotor thrust bearing.