Flight control system

Claim 1

A SYSTEM FOR PRODUCING A PITCH STEERING SIGNAL FOR AN AIRCRAFT FOR USE DURING STEADY STATE CLIMB AND DESCENT TO DAMP PHUGOID OSCILLATION OF THE AIRCRAFT, COMPRISING THE COMBINATION OF MEANS RESPONSIVE TO THE ANGLE OF ATTACK OF THE AIRCRAFT AND ACTING TO PRODUCE A FIRST SIGNAL REPRESENTING THE VALUE THEREOF, MEANS FOR PRODUCING A SECOND SIGNAL REPRESENTING THE RATE OF CHANGE OF THE INDICATED AIRSPEED OF THE AIRCRAFT, MEANS FOR COMBINING SAID SIGNALS IN SUCH POLARITY THAT THE SECOND SIGNAL OPPOSES THE FIRST SIGNAL WHEN THE RATE OF CHANGE OF INDICATED AIRSPEED AND THE ANGLE OF ATTACK HAVE THE SAME SIGN, AND MEANS ACTING TO DERIVE FROM THE COMBINED SIGNAL A PITCH STEERING SIGNAL THAT CHANGES IN A NEGATIVE DIRECTION IN RESPONSE TO A POSITIVE RATE OF CHANGE OF AIRSPEED DURING PHUGOID OSCILLATION AND CHANGES IN A POSITIVE DIRECTION IN RESPONSE TO A NEGATIVE RATE OF CHANGE OF AIRSPEED DURING PHUGOID OSCILLATION, SO AS TO ALLOW A CHANGE IN THE ANGLE OF ATTACK IN THE DIRECTION OPPOSITE TO THE DIRECTION OF A CHANGE OF THE PITCH STEERING SIGNAL TO COMPENSATE FOR THAT CHANGE IN THE PITCH STEERING SIGNAL AND TO DAMP THE PHUGOID OSCILLATION.