The Boeing Company

John Koon-hung Ho

Kioumars Najmabadi

Edward E Coleman

Chuong B Tran

David W Grubb

Michael D Bills

Paul Jay Cline

William F Shivitz

Paul C Strefling

William F Carver

Thomas C Ramsey, Jr

Robert James McIntosh

Bruce Mays Fritchman

Steven Cook Stone

Richard D Johnson

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.

Methods and systems for controlling aircraft flight performance

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.

Wing-body load alleviation for aircraft

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.

Aircraft multi-axis modal suppression system

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.

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Shoreline, WA, United States of America

John Koon-hung Ho