<p>Normal high load operation automatically varies nozzle area to maintain an optimum engine pressure ratio (EPR). An error signal representing fan damage is established by comparing the actual EPR to the predicted EPR. Compressor stalls are also monitored. In response to these signals a minimum nozzle area is set and modified. Automatic operation to hold EPR and afterburning is inhibited. Further signals representing satisfactory operation may reset the inhibiting action.</p>
