The Boeing Company

Edward E Coleman

Kioumars Najmabadi

Monte R Evans

Robert J Bleeg

Richard S Breuhaus

David W Grubb

Timothy A Nelson

Dorr Marshall Anderson

Chuong B Tran

John Koon-hung Ho

Michael D Bills

Tze L Siu

Daniel H Cartmell

Dianne Lynn McMullin

Paul Jay Cline

Jonathan Kyle Moore

John Koon-Hung Ho

Paul C Strefling

William F Shivitz

Michael S McCuen

Kevin H Milligan

William F Carver

Robert James McIntosh

Thomas C Ramsey, Jr

Brian Charles Bock

Richard D Johnson

Steven Cook Stone

Vincent M Walton

Christopher J Borland

John K Ho

Bruce Mays Fritchman

David P Marquis

Leo L Engstrom, Jr

Thomas C Ramsey

Paul J Cline

Robert J Mcintosh

Dianne L Mcmullin

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

Methods and apparatus to control aircraft horizontal stabilizers are described herein. One described method includes calculating, using a processor, a desired movement of a horizontal stabilizer of an aircraft to counteract a pitching moment of the aircraft, and controlling the horizontal stabilizer based on the desired movement.

Methods and apparatus to control aircraft horizontal stabilizers

A method for vertical gust suppression due to turbulence for an aircraft having at least one of direct lift control surfaces or pitch control surfaces. The method includes sensing atmospheric turbulence, measuring the sensed atmospheric turbulence to generate turbulence data, generating a command based on the turbulence data, and applying the command to aircraft controls to actuate the direct lift control surfaces or the pitch control surfaces based on the turbulence data. Therefore, an aircraft response to the actuation of the direct lift control surfaces or the pitch control surfaces reduces a vertical acceleration, a pitch acceleration, a pitch rate, a pitch attitude or a structural load of the aircraft due to the turbulence. Thus, the method reduces the effects of vertical gusts of wind on the aircraft, improves the comfort level for aircraft passengers and crew, and reduces diversions the aircraft may take to avoid the turbulence.

Vertical gust suppression system for transport aircraft

A method for controlling control surfaces. A position limit is identified for movement of a control surface based on a load limit set for the control surface and a number of vehicle current operation parameters to form an identified position limit. Responsive to receiving a command to move the control surface on a vehicle to a new position, the control surface is commanded to move to a position within the identified position limit.

Horizontal tail load alleviation system

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

Methods and systems for linking input control signals, such as control signals used to control aspects of aircraft operation. In one embodiment, the method includes receiving first and second force signals corresponding to first and second forces applied to first and second controllers. The method can further include directing first and second position signals to the first and second controllers to move the first and second controllers to approximately the same positions. Each force signal is transmitted along a signal path, and the signal paths can be linked at a point where the signals on each path correspond to a quantity other that a position of a controller. The signal paths can be linked such that only one of the forces must exceed a threshold value for both controllers to be moved, and if one of the forces is outside a selected limit range, that force can be at least partially discounted.

Control system and method with multiple linked inputs

A bias correction system for use in a neutrally-stable aircraft having a control column and a pitch control system is provided. The position of the control column is generally represented by a control column position signal. The bias correction system is for removing control column bias when the control column is in a neutral position. The bias correction system includes a first combining unit for combining the control column position signal and a correction signal, and a switch. The switch includes activated and deactivated states. The switch is set to the deactivated state when the control column is physically displaced from its neutral position. The deactivated state allows the correction signal to remain at its last value, the activated state allows the correction signal to equal approximately the control column position signal. In one embodiment, the bias correction system includes a smoothing filter for receiving the control column position signal and outputting a smoothed correction signal when the switch is in the activated state. In another embodiment, the bias correction system includes a unit for limiting the correction signal to control column position signal values within a limited predefined range.

Aircraft pitch-axis stability and command augmentation system

A method of providing speed protection to a neutrally-stable aircraft including the calculation of at least one of a stall protection signal and an overspeed protection signal. The aircraft includes a pitch control system having a command pitch signal received from pilot input to a control column. The protection signal is provided to the pitch control system to limit the commanded pitch signal during flight. The calculation of a stall protection signal includes differencing the aircraft's current airspeed with a reference speed and multiplying the difference by a scaling factor that corresponds to the force required by the pilot to move the control column. The calculation of an overspeed protection signal includes calculating a first signal based on airspeed, calculating a second signal based on Mach, selecting the large of the two signal and passing it through a limiter. The limiter is a function of roll attitude and corresponds to the force required by the pilot to move the control column. Also provided is a method of calculating a flare compensation signal to emulate ground effects encountered by an aircraft while executing a landing. The flare compensation signal is determined using a table of gear heights versus flare compensation amounts. The flare compensation signal is limited to a value between zero and a positive upper limit.

Method of speed protection and flare compensation for use with aircraft

A number of different combinations of 'true/false' conclusions of the air/ground condition of an aircraft are analyzed and compared to automatically provide a signal to a flight control system of the aircraft to indicate whether the aircraft is in the air or on the ground, particularly during transition from air to ground or from ground to air.

System for providing an air/ground signal to aircraft flight control

Disclosed is a pitch-axis stability and command augmentation system (19) in which a pilot column input (.delta..sub.C) is provided to a pitch command processor (26), the output of which is a C*U feedforward command (C*U.sub.FFC) that is supplied as an additive input to a combining unit (20). The combining unit (20) receives a second additive input of an augmented feedback command signal (AFB.sub.COM). The resulting output is filtered and generates an elevator command signal (.delta..sub.e,FILT). The command processor (26) additionally supplies a corrected column position signal (.delta..sub.C,COR) to a pitch command C*U processor (26) that converts the corrected column position signal (.delta..sub.C,COR) into a C*U pitch command (C*U.sub.PilotCmd), representative of the pilot's requested elevator pitch which is generated by movement of the control cola. A computed C*U processor (32) forms a computed C*U signal (C*U.sub.Computed) that is based on the current state of the aircraft. The C*U processor (32) includes a speed stability processor (150) that computes the difference between a reference speed (V.sub.REF) and calibrated airspeed (V.sub.CAS). The speed stability processor (150) includes phugoid damping (400) in generating a speed error signal (E.sub.z), and providing a means by which the pilot may set a reference airspeed (V.sub.REF) by using a trim device. An underspeed protection signal (C*U.sub.Us) is supplied by a stall protection processor (416). A flare compensation signal (C*U.sub.FR) is supplied by a flare compensation processor (414). An overspeed protection processor (412) supplies an overspeed protection signal (C*U.sub.OS). A combining unit (424) is provided to combine the stall protection signal (C*U.sub.Us), flare compensation signal (C*U.sub.FR), and overspeed protection signal (C*U.sub.OS) to form a compensation and protection signal (C*U.sub.C&P). A combining unit (22) combines the pilot-requested C*U command (C*U.sub.PilotCmd), the computed C*U signal (C*U.sub.Computed), and the compensation and protection signal (C*U.sub.C&P). The resulting signal is an error signal (E.sub.C*U) which is supplied to an integrator (28) that outputs a C*U integral command signal (IC*U.sub.COM). Another combining unit (23) receives the C*U integral command signal (IC*U.sub.COM) and combines it with a pitch rate damping command signal (Q.sub.COM). The output of the combining unit (23) is the augmented feedback command signal (AFB.sub.COM).

Aircraft pitch-axis stability and command augmentation

A method and apparatus for managing the trim of an airplane stabilizer whose elevator is controlled by a highly augmented elevator control law is disclosed. The augmented portion of the elevator command ##EQU1## is evaluated(13) to determine if it is above or below a variable threshold whose magnitude is dependent on airspeed. Portions above or below the threshold are integrated (15) to determine if the augmented portion of the elevator command is rapidly or slowly diverging. A stabilizer trim command is rapidly produced if the augmented portion of the elevator command is rapidly diverging and produced more slowly if the augmented portion is slowly diverging. The stabilizer trim command causes the production of a trim up or trim down command (25/27) depending upon whether the stabilizer needs to be moved up or down. Trim up commands (25) are inhibited under certain conditions, such as when the tail of the airplane is near the ground, when the airplane angle of attack is above the point where further nose up trim would be ineffective, or when the stabilizer trim limit has been exceeded. Trim down commands (27) are inhibited when the stabilizer trim down limit has been exceeded. Trim up and trim down commands are also inhibited when the command would drive the stabilizer out of fair with the elevator. Finally, provision is made for direct stabilizer trim control by the pilot of the airplane in the event that the elevator is limited and, thus, the stabilizer is required to produce additional pitch response.

Method and apparatus for automatically trimming an airplane stabilizer

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Lake Forest Park, WA, United States of America

Edward E Coleman