Abstract: The present invention provides a method and device for automatically determining a capture trajectory of a flight trajectory for an aircraft, as well as a procedure and system for automatic guidance of an aircraft. The flight trajectory includes at least one lateral trajectory furnished at least with a plurality of rectilinear stretches. The capture trajectory is a lateral capture trajectory that allows the aircraft to join up laterally with a particular rectilinear stretch of the lateral trajectory of the flight trajectory. The capture trajectory is defined to allow a minimum capture duration. An automatic navigation mode is engaged as soon as requested by the pilot to, if necessary, capture and follow the planned flight trajectory.

Abstract: A method and device for controlling the attitude of an aircraft may employ spoilers that are arranged on the wings of the aircraft and whose respective angular positions can be adjusted by controllable actuators. A command attitude determining section determines a command attitude of the aircraft corresponding to an attitude that the aircraft must achieve. A command position calculator calculates command positions of the spoilers, corresponding to particular angular positions of the spoilers, making it possible to bring the aircraft to the command attitude. A control instruction calculator calculates control instructions for the controllable actuators, making it possible to bring the spoilers into the command positions, and applies the control instructions to the spoiler actuators.

Abstract: The flight control indicator may include a set of information sources, a computation unit connected to said set of information sources, and a head-up display device. The computation unit determines, on the basis of information emanating from the set of information sources, at least one maximum total slope of the aircraft. The maximum total slope corresponds to the maximum thrust and is obtained on the basis of the measurement of the current performance of the aircraft, extrapolated to the condition of maximum slope and in anticipation of an engine fault. The head-up display device presents, on a display screen, at least one indicator which indicates the maximum total slope and which is presented superimposed on the environment existing in front of the aircraft.

Abstract: A control system includes a rate-damping loop that uses a calculated angle-of attack error to non-linearly scale a rate-feedback signal so that at lower angle-of attack (AOA) error values, an acceleration feedback term plays a greater role in pitch compensation, while at greater angle-of-attack error values, a rate-feedback term plays a greater role in the pitch compensation. In some embodiments, a control system and method of controlling an angle-of-attack of a moving body are provided. A signal representing an angle-of-attack error is non-linearly combined with a signal representing a rate-of-change of an estimated angle-of-attack to generate a non-linear rate-damping signal. The non-linear rate-damping signal is subtracted from the signal representing the angle-of-attack error to generate a signal to control one or more elements of the moving body.

Abstract: A system and method are provided for precisely adjusting individual aircraft airspeed system in order to provide more accurate cruise Indicated Airspeed (IAS). The system includes a flight data computer, an autopilot, and airspeed displays. The flight data computer includes a first component that records in-service data to determine actual fuel mileage for the aircraft for comparison to a production rating fuel mileage. The flight data computer also includes a user interface that allows a user to set a Mach trim value based on the comparison and a third component that adjusts indicated airspeed based on the determined Mach trim value. The autopilot and airspeed displays receive the adjusted indicated airspeed.

Abstract: A computational air data method and system for estimating angle-of-attack and angle-of-sideslip of an aircraft utilizing a detailed aerodynamic model of the aircraft, extended Kalman filters, inertial system measurements of body rates and body accelerations, and computation of dynamic pressure.

Abstract: Pilot error is reduced and auto pilot operation is improved by the addition of capture information to the information provided on a cockpit display. The capture information, such as, for example, capture start point, last point to initiate capture, trajectory during capture, and capture overshoot region provide information to the pilot regarding the correct initiation of capture. Pilots are therefore better able to evaluate the ongoing performance of the automation or auto pilot systems and to trust that the auto pilot is functioning as desired. Furthermore, the pilot operating the aircraft in manual mode receives guidance based on this information to better know when to initiate capture of the assigned altitude or vertical path.

Abstract: An aircraft flight control system is provided for reducing the likelihood of an aircraft tailstrike. The flight control system includes a pitch command provided to a pitch control device for altering the aircraft's pitch attitude. The improvement is a system of altering the pitch command to avoid an aircraft tailstrike. The improvement includes determining a current tailskid closure rate and a current tail height; comparing the current tailskid closure rate with a threshold closure rate to determine an excess closure rate amount; and adding an incremental nose-down pitch command with the pitch command to avoid a potential aircraft tailstrike. The threshold closure rate is dependent upon the current tailskid height. The incremental nose-down pitch command is calculated as a function of the excess closure rate amount.

Abstract: The pilot's awareness of the aircraft's state is enhanced by supplementing the flight modes area (FMA) in the upper region of the primary flight display (PFD) with additional annunciators. The FMA in the present invention displays, in the active lateral modes region, the name of the waypoint the aircraft is flying towards and, if the waypoint is part of a published procedure, the procedure name is displayed in this area. Moreover, if the controls of the aircraft are set for a specific target, then the target, along with the mode annunciators, are displayed in the active vertical modes region of the FMA. Furthermore, if the aircraft starts to deviate from the preselected altitude, the pilot is alerted of the uncoordinated condition by a CHECK ASEL annunciation which is displayed in the lower center region of the FMA, namely below the autopilot (AP) annunciator.

Abstract: A method and computer program product are provided for controlling the actuators of an aerodynamic vehicle to affect a desired change in the time rate of change of the system state vector. The method initially determines the differences between anticipated changes in the states of the aerodynamic vehicle based upon the current condition of each actuator, and desired state changes. The differences between the anticipated and desired state changes may be weighted based upon a predetermined criteria, such as the importance of the respective states and/or the weight to be attributed to outliers. The differences between the anticipated and desired state changes are converted to the corresponding rates of change of the actuators. These changes in the actuators may be limited to within predefined bounds. Control signals are then issued to the actuators to affect the desired change in the time rate of change of the system state vector.

Abstract: A method and apparatus are provided for controlling a dynamic device having multi-inputs and operating in an environment having multiple operating parameters. A method of designing flight control laws using multi-input, multi-output feedback LTI'zation is also provided. The method includes steps of: (i) determining coordinates for flight vehicle equations of motion; (ii) transforming the coordinates for the flight vehicle equations of motion into a multi-input linear time invariant system; (iii) establishing control laws yielding the transformed equations of motion LTI; (iv) adjusting the control laws to obtain a desired closed loop behavior for the controlled system; and (v) converting the transformed coordinates control laws to physical coordinates.

Abstract: A ground proximity warning system, method and computer program product are provided that controllably alter the base width of the alert envelope in order to accommodate uncertainties associated with the current position of the aircraft. In one embodiment, the ground proximity warning system, method and computer program product controllably alter the base width of the alert envelope depending upon an error value, i.e., an uncertainty, associated with the current position of the aircraft. Since the error value associated with the current position of the aircraft is largely dependent upon the type of navigation equipment onboard the aircraft, the ground proximity warning system, method and computer program product of another embodiment controllably alter the base width of the alert envelope depending upon the type of navigation equipment that provides the current position of the aircraft.

Abstract: A method, an apparatus and a computer program product are provided for accurately determining the vertical speed of an aircraft in a manner independent of signals provided by an air data computer, an inertial reference system and an inertial navigation system. Initially, a first vertical velocity of the aircraft is determined based upon a pressure altitude value associated with the aircraft. A second vertical velocity of the aircraft is also obtained from a GPS receiver carried by the aircraft. The first and second vertical velocities are then combined to determine the vertical speed of the aircraft. In this regard, the first and second vertical velocities are combined by complimentarily filtering the first and second vertical velocities. More particularly, the first vertical velocity is typically low pass filtered to remove high frequency noise that is attributable to the relatively low resolution of the first vertical velocity value.

Abstract: An improvement to an aircraft flight control system is provided for reducing the likelihood of an aircraft tailstrike. The flight control system includes a pitch command provided to a pitch control device for altering the aircraft's pitch attitude. The improvement is a system of altering the pitch command to avoid an aircraft tailstrike. The improvement includes determining a current tailskid closure rate and a current tail height; comparing the current tailskid closure rate with a threshold closure rate to determine an excess closure rate amount; and adding an incremental nose-down pitch command with the pitch command to avoid a potential aircraft tailstrike. The threshold closure rate is dependent upon the current tailskid height. The incremental nose-down pitch command is calculated as a function of the excess closure rate amount.

Abstract: An aircraft flight control system is provided for reducing the likelihood of an aircraft tailstrike. The flight control system includes a pitch command provided to a pitch control device for altering the aircraft's pitch attitude. The improvement is a system of altering the pitch command to avoid an aircraft tailstrike. The improvement includes determining a current tailskid closure rate and a current tail height; comparing the current tailskid closure rate with a threshold closure rate to determine an excess closure rate amount; and adding an incremental nose-down pitch command with the pitch command to avoid a potential aircraft tailstrike. The threshold closure rate is dependent upon the current tailskid height. The incremental nose-down pitch command is calculated as a function of the excess closure rate amount.

Abstract: A method of changing a preselect altitude value includes receiving an input from a pilot. In response, the preselect altitude value is changed by a first amount from a current preselect altitude value toward a minimum altitude value. The first amount that the preselect altitude value is changed by is dependent upon a proximity of the current preselect altitude value to the minimum altitude value such that if a difference between the current preselect altitude value and the minimum altitude value is greater than a first predetermined interval, the first amount is equal to the first predetermined interval. If the difference between the current preselect altitude value and the minimum altitude value is less than the first predetermined interval, then the first amount is less than the first interval, for example resulting in the preselect altitude value being set directly to the minimum altitude value.

Abstract: 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.

Abstract: A method, an apparatus and a computer program product are provided for accurately determining the vertical speed of an aircraft in a manner independent of signals provided by an air data computer, an inertial reference system and an inertial navigation system. Initially, a first vertical velocity of the aircraft is determined based upon a pressure altitude value associated with the aircraft. A second vertical velocity of the aircraft is also obtained from a GPS receiver carried by the aircraft. The first and second vertical velocities are then combined to determine the vertical speed of the aircraft. In this regard, the first and second vertical velocities are combined by complimentarily filtering the first and second vertical velocities. More particularly, the first vertical velocity is typically low pass filtered to remove high frequency noise that is attributable to the relatively low resolution of the first vertical velocity value.

Abstract: A method and system is disclosed for using inertial sensors in an Inertial Navigation System (INS) to obtain analytic estimates of angle-of-attack (&agr;) and sideslip angle (&agr;). The inertial sensors consist of one or more accelerometers which produce the estimated signals for angle-of-attack (&agr;) and sideslip angle (&bgr;). Three methods are shown for obtaining &agr; and &bgr; estimates from INS information and are programmed into a nonlinear simulation of a relaxed stability aircraft requiring a high level of artificial stability augmentation in its flight control system. Simulation results from the nonlinear simulation for each of the three methods were compared with the results obtained when conventional probes were used to obtain direct measurements of &agr; and &bgr;.

Abstract: A flight warning system comprises an outside temperature probe for sensing outside temperature, a gyroscope for sensing aircraft bank angle, a static transducer for sensing static pressure, and a dynamic pressure sensor for receiving total pressure from a pitot tube. A computer is responsive to the gyroscope, static transducer, outside temperature probe and dynamic pressure sensor calculates whether the aircraft is entering a stall condition by comparing the aircraft's bank angle with the stall bank angle. The computer can also calculate whether sufficient altitude exists for the aircraft to safely return to a field after a power failure. An output device can also be provided for indicating the existence of said sufficient altitude, and a stall indicator can be provided for indicating whether the aircraft is entering a stall condition. A method for determining the existence of a stall condition with the aircraft is also disclosed.

Abstract: A flight control system according to the present invention includes a vertical acceleration control device for calculating a pitch axis steering angle command to make a difference between a vertical acceleration of an airplane and a target turn acceleration to zero, and transmitting it as a variable to a pitch axis control device, a reference bank angle device for calculating a reference bank angle from the target turn acceleration, an altitude control device for calculating a bank angle correcting quantity from a difference between an altitude of the airplane and a target altitude and obtaining a bank angle command by correcting the reference bank angle, and a roll axis control device for calculating a roll axis steering angle command for make a difference between a real bank angle and the bank angle command to zero and for transmitting it as a variable to a roll axis control device.

Abstract: A device for assisting the piloting of a vehicle by instruments. Various indications are displayed on an aircraft head-up view finder including a horizontal line graduated in terms of heading, a perpendicular line graduated in terms of atitude, an aircraft symbol representing the direction of the longitudinal axis of the aircraft above the horizontal line and a velocity vector symbol representing the tracking slope followed by the aircraft with respect to the ground. These are determined with respect to the tracking and atitude scales. The guidance window whose position is references with respect to the same axis is also displayed. The pilot must control the aircraft as to bring the velocity vector into the guidance window and keep it there. The window is placed on the screen at a position which is computed by the computer and which corresponds to the direction of a point of the desired path of the aircraft, this point being at a predetermined distance ahead of the aircraft.

Abstract: An aircraft autopilot system provides a wind correction angle which is added to the desired course to provide commanded heading, the wind correction angle being generated as a proportional and integral function of ground track error. When the aircraft is off its desired course, it can be returned to the desired course by means of a course intercept angle, added to the desired course, to provide a corrected commanded course, the course intercept angle being a proportional function of the perpendicular error (the lateral distance of the aircraft from the original course) suitably limited to some angle within 90.degree. of the desired course. The course correction angle may be generated as a proportion of the perpendicular course error determined by the degree of importance of accuracy, and may be switched over to a course directly toward a waypoint in dependence upon the importance of efficiency.

Abstract: A process and a device for verifying the consistency of the measurements made by an angle-of-attack probe (2) mounted on an aircraft. The device (1) includes:first system (3) for computing a first coefficient of lift of the aircraft from a measurement from the probe (2) and from data relating to the aircraft;second system (5) for computing a second coefficient of lift from information about the aircraft;system (6) for computing the difference between the first and second coefficients of lift and for deducting therefrom that the measurement is or is not consistent.

Abstract: In a method of flight control in which a thrust command is computed based on the total aircraft energy error relative to flight path and speed control commands, and an elevator command is computed based on the energy distribution error relative to the same flight path and speed control commands, an improvement is provided including an elevator control command in response to a column control input by the pilot. In the short term, the computing establishes a change in flight path angle beyond the sustainable flight path angle at the trim speed for the prevailing thrust condition. In the long term, the computing establishes a change in speed relative to a set reference speed, the speed change being proportional to the column control input. In the long term, the computing establishes a flight path angle equal to a sustainable value for the prevailing thrust condition and the altered speed condition.

Abstract: An aircraft turn guidance system comprises a satellite navigation receiver connected to a turn path computer. Position, velocity and waypoint headings and distances are communicated from the satellite navigation receiver to the turn path computer. Roll angle, airframe and airspace constraints are fed to the turn path computer which computes a constant roll turn for the constraints when transitioning a waypoint from the inbound to outbound legs. The effects of wind on the airmass are computed in to account for real world conditions.

Abstract: An apparatus and method for detecting vertical gusts of wind on board an aircraft in cruising flight is disclosed. The method includes the steps of: calculating an absolute value (.vertline..alpha.-.theta..vertline.) of a difference between a pair of first differentials with respect to time (.alpha. and .theta.) of a current incidence .alpha. and a current pitch attitude .theta. of the aircraft, comparing the absolute value to an upper threshold (Ss), comparing a current Mach number (M) of the aircraft to a Mach number threshold (Mo), and generating an electrical signal that represents presence of a vertical gust of wind when the absolute value is above the upper threshold, when the current Mach number is above the Mach number threshold, and when aerodynamic flaps and slats of the aircraft are in a clean configuration.

Abstract: The present invention relates to a method and a device for guiding an aircraft (A) according to a prescribed vertical flight path (T).According to the invention:the vertical distance he between said aircraft (A) and said flight path (T) is determined;the difference ve between the actual vertical velocity (Vz) of the aircraft (A) and the vertical velocity (Vzth) which it would have on the flight path (T) is determined;a vertical acceleration variation Anz is calculated:.DELTA.nz=((k1.(he-hc))+(ve-vc)).k2k1 and k2 being characteristic coefficients, hc and vc being precontrol terms, and k1.(he-hc) being restricted; andsaid restricted variation Anz is applied to the aircraft.

Abstract: The apparatus of this invention includes a pilot-induced oscillation (PIO) detector, a PIO compensator and a pilot input modifier. The PIO detector is coupled to receive aircraft state signal including the aircraft's pitch, roll and yaw attitudes. The PIO detector is also coupled to receive pilot control signal generated by the aircraft's pilot by manipulation of flight control instruments. Preferably, the PIO detector includes a feature calculator and a discriminator. Based on the aircraft state signal and the pilot control signal, the feature calculator generates at least one feature signal indicative of whether a PIO or non-PIO condition exists in the aircraft. The feature calculator supplies the feature signal to the discriminator, that uses the feature signal to determine whether or not a PIO condition exists.

Abstract: An automatic device for maintaining an aircraft at an authorized speed compatible with the technical capabilities of the aircraft includes:a system for comparing the effective speed of the aircraft with reference speeds defined in accordance with the technical capabilities of the aircraft,a system for calculating, on the basis of such comparison, modified control values to align the effective speed with these reference speeds, anda system for imposing one of these calculated values on the aircraft, if this is necessary to maintain the aircraft at an authorized speed.

Abstract: A self adaptive limiter for use in aircraft control systems during approach and landing is disclosed. Estimated flight path angle is continuously computed during the glidepath tracking phase until a predetermined lock altitude above ground when a nominal flight path angle is latched. Nominal vertical speed is continuously computed below the lock altitude as a function of the latched nominal flight path angle and ground speed of the aircraft. A vertical speed limit function is generated as a function of the nominal vertical speed and radio altitude. During approach and landing a pitch limit is computed from the vertical speed limit, vertical speed, ground speed, and pitch. When a pitch command to the autopilot exceeds the pitch limit(i.e. commands excessive pitch down attitude), it is limited to the pitch limit thus preventing the aircraft from descending below a safe altitude.

Abstract: In an aircraft under autopilot control, a stall protection system overrides established autopilot parameters in response to a monitored angle of attack for the aircraft exceeding a trigger angle of attack. The trigger angle of attack is established with reference to a stick shaker angle of attack for the aircraft. When the aircraft exceeds the trigger angle of attack, the stall protection system produces an error signal causing the autopilot to seek an angle of attack 1 degree below the stick shaker angle of attack. Initially, the stall protection system provides a boost command to the error signal to accelerate the response of the aircraft to the error signal. The boost command is produced by a driving signal generator that selects one of four driving signals in response to monitored flap angle and impact pressure.

Abstract: A VTOL/STOL free wing aircraft includes a free wing having wings on opposite sides of a fuselage connected to one another respectively for free rotation about a spanwise access. Improved control upon landing of the aircraft is achieved by utilizing a variable pitch propulsion system, enabling the pitch of the propeller to be varied corresponding to the speed of the aircraft and angle of approach upon descent.

Abstract: A cyclic stick system for a helicopter includes sensors for measuring at least one parameter representative of the current flight status of the helicopter. In response to the at least one parameter, the cyclic stick system either (1) continuously and automatically recenters the forces on the cyclic stick, thus canceling out the residual static forces, or (2) allows the pilot fully to feel the countering action of the elastic return device on the cyclic stick.

Abstract: 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.

Abstract: A synchrophaser for a multi-engine, propeller-driven aircraft including a filter that automatically compensates for misalignment of blade position sensor tabs through derivation and application of a correlation coefficient. The correlation coefficient is calculated in a self-adjustment derivation, utilizing a dynamic tolerance band, providing increased accuracy in propeller speed determination. The correlation coefficient brings about an apparent uniform distribution of blade position sensors, as seen by the synchrophaser, thus eliminating a primary source of cyclic propeller speed disturbances. The correlative filer accomplishes its task without the phase shifting normally encountered in other digital filtering technique.

Abstract: Aircraft input signals of selected altitude (h.sub.s), selected vertical speed (h.sub.s), current altitude (h), current vertical speed (h), current pitch attitude (.theta.), current normal acceleration (N.sub.z) and current pitch rate (Q) are processed to produce an elevator command (.delta..sub.e) that will result in a smooth vertical transition of the aircraft for various autopilot vertical maneuvers, including altitude capture and hold, glideslope capture and hold, and flare control.

Abstract: The disclosed optoelectronic device is designed to facilitate the piloting of an aircraft under conditions of poor visibility, notably during landing at the stage when the aircraft approaches a runway. It consists of a collimator which displays, in addition to the artificial skyline, miniature aircraft index and attitude bars, a slope scale positioned across and on either side of the artificial skyline, at the position of the selected course chosen by the pilot. This slope scale, depicted in the form of a line of dots spaced out at one slope degree, enables the pilot to be presented simultaneously with information on selected course and slope and enables the determining of pitch attitude with high precision.

Abstract: A model-following aircraft control system in which a roll rate command in Euler coordinates is integrated to provide a bank angle command, which has actual bank angle subtracted therefrom to provide a command error that is converted back to aircraft body coordinates for use, so long as the pitch attitude of the aircraft does not approach zenith or nadir. But, while the absolute value of the pitch attitude exceeds 85.degree. the last error generated before exceeding 85.degree. is converted to body coordinates for use by the aircraft, and the initial integrated value of attitude command, for use when the pitch angle reverts below 85.degree., is formed as the sum of said last error and the actual attitude angle of the aircraft.

Abstract: A velocity command system is provided with a velocity stabilization mode wherein aircraft flight path referenced velocities are determined with respect to an inertial frame of reference, the flight path referenced velocities are held constant during pilot commanded yaw maneuvers so that the aircraft maintains a fixed inertial referenced flight path regardless of the pointing direction of the aircraft. Velocity control with respect to an inertial frame of reference is accomplished by controlling the aircraft flight path based on aircraft body referenced commanded lateral and longitudinal acceleration and based on aircraft body referenced lateral and longitudinal centrifugal acceleration. Operation in the velocity stabilization mode is provided in response to the manual activation of the velocity stabilization mode by the pilot, provided that the aircraft is already operating in the ground speed mode and the aircraft is not in a coordinated turn.

Abstract: According to the invention, attenuator means (8) are provided, making it possible to limit the rate of rotation of the airplane on takeoff, so as to avoid the tail of the airplane striking the ground and to reduce the dispersion of the rotation rates.

Abstract: A wind shear detection and alert system, compensated for the calibrated airspeed of the aircraft to minimize nuisance wind shear alerts. The wind shear detection and alert system (10) determines a reference airspeed as a function of flap position, with respect to a minimum maneuver airspeed signal (60) provided by a stall warning computer on the aircraft. The reference airspeed is subtracted from a calibrated airspeed signal (76) that has been filtered to remove minor variations in the signal using a Laplace filter (68). The differential airspeed is further filtered by another Laplace filter (78), producing a filtered differential airspeed signal (70), which the system uses to determine a delta threshold (48) to be applied in compensation for the aircraft airspeed to a wind shear alert reference signal. As the filtered differential airspeed increases, the delta threshold signal increases the absolute level of the wind shear alert threshold, reducing the likelihood of unnecessary wind shear alerts.

Abstract: Process for flying an aircraft in the "elevator speed maintenance mode" during altitude changes, in which for acquiring and/or maintaining a nominal speed it is supplied to the flight computer at the same time as the instantaneous speed of the aircraft, said computer producing the elevator control instruction, characterized in that a nominal speed is also simultaneously transmitted in continuous manner to the automatic thrust control member of the engines and in that the process is performed during two successive sequences, namely:a first sequence during which the elevator only receives a nose up instruction (on climbing) or a dive instruction (on descending) and the engines move to full thrust in the first case or to idling speed in the second anda second sequence, following the first, during which the real nominal speed is supplied to the elevator instruction computer and said same nominal speed increased (on climbing) or decreased (on descending) by a margin is supplied to the automatic thrust control memb

Abstract: Method for signalling insufficient maneuverability of an aircraft according to which:in a preparatory phase: with the aid of a plurality of N flight configurations, the weighting coefficients between three quantities G1, G2, G3 are determined, representative respectively of the acceleration, the slope angle of the trajectory and the risk of stalling, coefficients such that the weighted sum of said quantities is less than a threshold when maneuverability is insufficient;in an in-flight utilization phase: said weighted sum is calculated and a signal signifying insufficient maneuverability is generated if said sum is less than said threshold.Application to controlling aircraft.

Abstract: A system for integrated pitch and thrust control of an aircraft.

Abstract: To prevent propeller overshoot, a propeller governor control generates a signal which modifies a speed command issued to a propeller governor. The signal causes the propeller governor to change blade pitch before the propeller reaches its commanded speed. The propeller governor control also compensates for small calibration errors in the propeller governor.

Abstract: A low airspeed alerting system for alerting the pilot of an aircraft of insufficient airspeed during a landing monitors various readily available signals representative of flight parameters of an aircraft such as pitch angle, vertical speed and true airspeed and advises the pilot when the airspeed of the aircraft is approaching an airspeed (kinetic energy) that is too low with respect to the ground to maintain the aircraft flying along the desired flight path without stalling, or without action by the pilot in time to recover.

Abstract: A helicopter flight control system includes an automatic turn coordination system which provides a coordinating yaw command signal to the tail rotor of the helicopter. The system stores on command a trim attitude (e.g., signals indicative of bank angle, lateral ground speed, and lateral acceleration) about which automatic turn coordination is provided, thus providing the pilot with automatic turn coordination about attitudes other than wings level.

Abstract: A helicopter fly-by-wire flight control system (21) includes a model following control system architecture which provides the pilot with maneuvering feel. Maneuvering feel is generated by varying the gain of a rate model (52) in the control system to schedule a constant sidearm controller force per g of load factor currently on the helicopter main rotor. This gain variation works in conjunction with control logic which requires the pilot to apply a nose up pitch command during steep banked turns in order to offset a control system induced downward (pitch) bias of the aircraft nose. The control system induced bias is generated only during steep banked turns, thus allowing the pilot to fly shallow banked coordinated turns without having to apply a nose up pitch command.

Abstract: A helicopter flight control system (21) includes a model following control system architecture which automatically provides a coordinating yaw command signal to the helicopter tail rotor to coordinate helicopter flight during a low speed banked turn. The control system processes information from a variety of helicopter sensors (31) in order to provide the coordinating yaw command signal on an output line (72) to the tail rotor (20) of the helicopter.