Abstract: Aircraft and methods and systems for controlling performance of an aircraft. The methods and systems allow the aircraft to meet a performance requirement using a set of aircraft flight data and actuators connected to control surfaces. Performance data for primary and secondary actuators are obtained to select between a primary control law for controlling the primary control surface, a secondary control law for controlling the secondary control surface, and a blended control law that controls the primary and secondary control surfaces together. If the primary control surface cannot meet the aircraft performance requirement using the primary control law, the blended control law is implemented if the primary and secondary control surfaces can be used together to meet the performance requirement; otherwise the secondary control surface is used, using the secondary control law, to meet the aircraft performance requirement.

Abstract: A computer implemented method, apparatus, and computer usable program product for symmetric and anti-symmetric control of aircraft flight control surfaces to reduce wing-body loads. Commands are sent to symmetrically deploy outboard control surfaces to shift wing air-loads inboard based on airplane state and speed brake deployment. Surface rate retraction on a wing with peak loads is limited to reduce maximum loads due to wheel checkback accompanied by utilization of opposite wing control surfaces to retain roll characteristics. Airloads are shifted inboard on a swept wing to move the center of pressure forward, thereby reducing the tail load required to perform a positive gravity maneuver. In a negative gravity maneuver, speed brakes are retracted, thereby reducing the positive tail load and reducing the aft body design loads. High gain feedback commands are filtered from wing structural modes above one hertz by a set of linear and non-linear filters.

Abstract: A computer implemented method, apparatus, and computer usable program product for symmetric and anti-symmetric control of aircraft flight control surfaces to reduce wing-body loads. Commands are sent to symmetrically deploy outboard control surfaces to shift wing air-loads inboard based on airplane state and speed brake deployment. Surface rate retraction on a wing with peak loads is limited to reduce maximum loads due to wheel checkback accompanied by utilization of opposite wing control surfaces to retain roll characteristics. Airloads are shifted inboard on a swept wing to move the center of pressure forward, thereby reducing the tail load required to perform a positive gravity maneuver. In a negative gravity maneuver, speed brakes are retracted, thereby reducing the positive tail load and reducing the aft body design loads. High gain feedback commands are filtered from wing structural modes above one hertz by a set of linear and non-linear filters.

Abstract: Vibrations due to excitation of the natural modes of an aircraft's body are suppressed by an active multi-axis modal suppression system. Dedicated sensors are positioned in the aircraft at optimal locations for sensing modal induced vibrations. The sensor produced signals are processed through control logic which, in response thereto, and in response to aircraft inertial, velocity and altitude related signals produces output control signals. The control signals effect control surface deployment creating forces to suppress the natural mode induced vibrations on multiple geometric axis's. More particularly, a symmetric and anti-symmetric control surface deployments are used on one or more geometric axis'to damp lateral, longitudinal, vertical and most importantly torsional vibrational modes.

Abstract: Vibrations due to excitation of the natural modes of an aircraft's body are suppressed by an active multi-axis modal suppression system. Dedicated sensors are positioned in the aircraft at optimal locations for sensing modal induced vibrations. The sensor produced signals are processed through control logic which, in response thereto, and in response to aircraft inertial, velocity and altitude related signals produces output control signals. The control signals effect control surface deployment creating forces to suppress the natural mode induced vibrations on multiple geometric axis's. More particularly, symmetric and anti-symmetric control surface deployments are used on one or more geometric axis's to damp lateral, longitudinal, vertical and most importantly torsional vibrational modes.

Abstract: Vibrations due to excitation of the natural modes of an aircraft's body are suppressed by an active multi-axis modal suppression system. Dedicated sensors are positioned in the aircraft at optimal locations for sensing modal induced vibrations. The sensor produced signals are processed through control logic which, in response thereto, and in response to aircraft inertial, velocity and altitude related signals produces output control signals. The control signals effect control surface deployment creating forces to suppress the natural mode induced vibrations on multiple geometric axis's. More particularly, symmetric and anti-symmetric control surface deployments are used on one or more geometric axis's to damp lateral, longitudinal, vertical and most importantly torsional vibrational modes.

Abstract: A method and apparatus for use with an aircraft autopilot to prevent an aircraft part from striking the ground during near ground maneuvers by employing a protection circuit between the outer loop and the inner loop of the control chain between the autopilot and the control surface, the prevention circuit producing an output signal when there is a possibility of ground strike which output signal operates to reduce the control surface command signal from the inner loop to the control surface and thus be rapidly responsive to aircraft attitude changes that could produce ground strike.