Abstract: A method and apparatus for determining the time remaining for maximum control action to be taken in order to achieve a desired objective (i.e., the chronodrasic interval) is disclosed. The method and apparatus continuously determines the amount of a parameter (e.g., runway distance) required to achieve a desired objective (e.g., stopping an aircraft before reaching the end of a runway on landing or accelerating an aircraft so that it reaches rotation speed before reaching the end of a runway on takeoff) if maximum control action is applied. The method and apparatus also continuously determines the total amount of the parameter remaining. The chronodrasic interval is then determined by deducting the amount of the parameter required to achieve the desired objective if maximum control action is taken from the total amount of the parameter remaining; and, dividing the result by a preselected (e.g., present or maximum) rate of change of the parameter.

Abstract: To increase the effectivity of warnings and to decrease nuisance warnings in a ground proximity warning system having several modes of operation, the switching from one mode to another is done as a function of radio altitude and time. In addition, in a ground proximity warning system where a warning signal is generated in accordance with a predetermined relationship between flight parameters, one or more of these parameters can be varied as a function of radio altitude and time in order to, for example, increase the altitude above ground as a function of radio altitude and time from take-off that a terrain clearance warning is generated or to decrease as a function of radio altitude and time, the radio altitude below which a negative climb after take-off warning is generated.

Abstract: A system for providing an indication of a glidepath for aircraft using a conventional altimeter having a graduated dial scale and a rotatable pointer includes a plurality of individual indicating lights spaced around the circumference of the dial which are individually controlled by an onboard microcomputer to provide a time dependent, moving indication of a descent rate on the dial scale corresponding to a safe, theoretical glidepath, which indication may be followed by the altimeter pointer to maintain the aircraft on the glidepath. The microcomputer includes a microprocessor control unit, a random access memory for temporary data storage and a read only memory for permanent storage of programmed instructions for computing the glidepath. A manually operable keyboard device permits entry of glidepath data regarding the aircraft's speed, position, etc.

Abstract: A landing display system for indicating to the pilot of an aircraft the relationship between his aircraft and a landing runway includes an aircraft symbol providing attitude information with respect to a reference horizon, a velocity vector indicative of the projected flight path of the aircraft, a descent profile vector indicative of the projected descent path of the aircraft, and a runway symbol in perspective to the aircraft. By reference to these displays the pilot can ascertain not only the present position of his aircraft with respect to the runway, but also the consequences of various corrective maneuvers accomplished with the aircraft.

Abstract: Aircraft altitude, ground velocity, and altitude rate signals are input to a computer which, using a unique control law, generates a pitch control surface command signal suitable for guiding an aircraft on its flare path to a specified runway touchdown point despite varying wind conditions.

Abstract: A system for providing an optimum lift demand signal for aircraft maneuvers such as "go-around" includes a computer for generating a reference angle of attack signal which is functionally related to the aircraft's vertical velocity. The reference signal is compared with a signal corresponding to the aircraft's actual angle of attack, thereby producing an error signal. The error signal is utilized as a control to the aircraft's dynamics for optimizing the aircraft's climb-out performance.

Abstract: Avionics apparatus for providing to a pilot readings of temperature, pressure altitude, and density altitude. Sensors provide electrical signals responsive to ambient temperature and pressure, and a functional module operates on signals derived from said sensors to provide signals indicative of the pressure altitude and density altitude. A multiplexer and display respond to a mode selection switch to provide visual readouts of temperature in degrees Fahrenheit and in degrees Celsius, and altitude.

Abstract: During a take-off or missed approach phase of operation the aircraft's maximum barometric altitude is retained in a memory element and compared to the aircraft's current altitude, and if the aircraft's current barometric altitude should be below the maximum altitude by a predetermined amount based on the aircraft's radio altitude, a voice warning is generated indicating that the aircraft is descending. Landing gear and flaps are monitored by the system and if the gear or flaps are down, an additional voice warning is generated indicating that the gear or flaps are down.

Abstract: A system for providing an aircraft pilot and/or autothrottle and go-around pitch axis control with information when a go-around should be initiated during an approach in response to either a hazardous flight status of the aircraft or to wind shear encounter by the aircraft. The present system utilizes a gain schedule control law based on the bug speed set by the pilot and on pilot go-around criteria to trigger a go-around signal for the pilot and/or the automatic control systems.

Abstract: A system for providing within the cockpit of an aircraft to the operator thereof a dynamic indication of climatic conditions at an airport. Such climatic conditions might include wind direction, wind speed, visibility, barometric pressure, temperature, and cloud height, among others. A transmitting station within the airport includes one or more climatic condition sensors such as a wind vane, an anemometer, a barometer, etc., an encoder for providing an encoded signal indicative of the sensed climatic conditions, and a radio transmitter for transmitting the encoded signal. A receiving station within the aircraft includes a radio receiver for receiving the transmitted encoded signal, a decoder for decoding the encoded signal to provide the dynamic climatic condition data, and a display for displaying that data.

Abstract: An altitude difference measuring apparatus for measuring the difference between the altitudes at a first and second points on the basis of the barometric difference between the points, having an air pressure holding section with an electromagnetic valve for hermetrically containing an amount of air. At the first place an amount of the ambient air is held hermetrically in the air pressure holding section, and at the second place the barometric difference between the air pressure in the air pressure holding section and the ambient air pressure is converted into an electric signal, and in accordance with the electric signal the difference between the altitudes at the first and second points is indicated.

Abstract: Apparatus for monitoring the acceleration of an aircraft moving along the ground includes a linear accelerometer (FA) and a rate gyroscope (RG). The accelerometer FA is fixed to the frame of the aircraft with its sensitive axis substantially horizontal, and circuit means A3, A4, are provided to null any output when the aircraft is at rest. The rate gyroscope RG is arranged to correct for any misalignment of the axis of the accelerometer, and further circuits A1, A2 null the output of the gyroscope while the aircraft is at rest. An amplifier A5 adds the outputs of the accelerometer and gyroscope channels, and correction amplifier A6 and unit AD correct the output of the summing amplifier A5 for aerodynamic drag resistance of the aircraft at any instant. The corrected output is applied to a suitable indicator such as a meter M.

Abstract: A take-off safety indicator for an aircraft has a double movement meter with a crossover pointer indication. The meter movements are driven respectively by inputs representative of speed and distance along the runway. The crossover point follows a locus and the optimum locus is shown on a background card selectable from a number of cards in dependence upon prevailing conditions.

Abstract: A take-off director system provides the pilot with a visual display on a flight director indicator of the aircraft acceleration required to reach V.sub.1 speed within a length of runway calculated so that upon take-off abort the pilot will yet be able to stop the aircraft on the remaining runway; if the aircraft is not sufficiently accelerated (the accelerometer is fitted along the aircraft longitudinal axis) to enable it to reach V.sub.1 speed on a given length of runway, the system warns the pilot to abort the take-off well before reaching of V.sub.1. There is also a take-off abort warning when the pressure on the legs at V.sub.cmg speed is not reduced by a certain value depending on airport data and aircraft type. When the aircraft reaches V.sub.R speed, the system warns the pilot to pull the control column and indicates the pitch angle required to clear any obstacles.

Abstract: A combined vertical speed and windshear indicator instrument for an aircraft has a graduated dial (2) and a conventionally driven pointer (3) for indicating the vertical speed. In addition the instrument has an independent pointer (4) which is driven so that it indicates, to the same scale as the vertical speed, the rate of change of total energy of the aircraft (energy rate) according to the formula dh/dt+(V/g)(dV/dt) where h is the height of the aircraft and V is its true air speed. Under stable flight conditions the pointers (3 and 4) will track together, but if there are any sudden changes, particularly changes due to windshear, the pointers will separate to indicate the effect of the changes so that the necessary corrective action can be taken by the pilot.

Abstract: A system to warn an aircraft pilot of a hazardous wind shear condition in which the rate of change of airspeed is compared to the ability of the aircraft to respond thereto. Any difference therebetween that exceeds a predetermined threshold is used to activate a suitable alarm or compensation device. Additional refinements include correcting the inertial speed inputs for vertical components and autopilot induced throttle changes, and correcting the air speed inputs for short term fluctuations.

Abstract: A performance advisory system which includes a display, a control unit and an onboard computer, the computer receiving inputs from aircraft instruments and gauges and from the control unit and providing advisory output information on the display.

Abstract: A meter face arrangement for use with a cross wind sensor that provides information indicating relative airspeed with respect to a probe, and also the direction of the relative wind, which permits an operator of an aircraft such as a helicopter pilot or an operator of a levitated vehicle or an observer in a ground installation to determine the relative movement of the air and also the relative direction of movement. The meter face is made so that the indicator will visually provide the direction and speed information from a single meter location using standard indicating hands to prevent confusion of the user.

Abstract: A system for automatically providing real-time weather and other pertinent information about an airport to an aircraft. The system can operate continuously or the pilot can utilize his radio telephone equipment to activate the information transmitter. Instantaneous weather information such as temperature, wind speed and direction and barometric pressure are supplied to a microcomputer which determines the real-time values as an average over a predetermined time period. The microcomputer then responds to the activating signal from the aircraft or operates continuously to selectively address the stored messages corresponding to the real-time information for transmission to the aircraft.

Abstract: A head-up visual approach instrument having a display of flight guidance information for a two-segment approach to touchdown. The display includes flight path indicia which the pilot aligns with an outside world aiming point, as the touchdown zone of a runway. During the first segment the flight path indicia is positioned as a function of aircraft altitude to define the changing sight angle to the target.

Abstract: The separation between aircraft approaching a common runway is minimized by measuring the existing wind conditions at a preselected point relative to the runway threshold and basing a prediction of the movement of wake vortices on the measured conditions. The prediction of vortex movement is based upon a vortex advisory algorithm prepared from a plot of wind conditions which predictably remove vortices from the flight path.

Abstract: A system of airplane instrumentation utilizing devices and procedures for dealing with wind shear on the final approach to a landing. The system is designed for use in a like manner on all approaches for landing to assure that a safe, stable speed be used during all landing approaches, and that the Pilot be apprised of the conditions his airplane is flying through at all times during the approach. The primary aim is to provide instrumentation which will aid the Pilot in achieving safe approach criteria, give him information on which to base his judgment, and eliminate accidents on the final approach due to wind shear.

Abstract: An on-board take-off performance indicator system for an aircraft includes a ground-engaging wheel which measures distance run during take-off and moves the slider of a selected one of a bank of potentiometers in response thereto. Each potentiometer is wound in accordance with a respective defined speed/distance characteristic. The selection of the potentiometer can be completely manual but is preferably in response to an electrical analogue of a graphical method which takes account of parameters individual to a particular take-off. An indication of expected speed in view of distance run is provided by the potentiometer output by means of an index on the airspeed indicator in the aircraft.

Abstract: A system for generating an optimum vertical speed command and controlling the aircraft to this command by allowing the aircraft to assume an optium trimmed condition for the thrust energy available which system utilizes the aircraft autopilot system.

Abstract: System for monitoring performance of an aircraft during ground-related operating condition, such as take-off and landing, to predict whether the aircraft can safely complete the operation. The performance of various known types of aircraft is predicted as a function of the distance which the aircraft has traveled along a runway. The actual progress of a known type of aircraft along a runway is then monitored to determine the actual velocity and position of the aircraft. Using the performance model for the known aircraft type, the remaining distance required for the aircraft to accomplish a particular operation, such as to reach take-off velocity or to decelerate to a stop, is predicted. The predicted distance is compared with the actual runway distance remaining for the aircraft to travel, and an alarm signal condition is generated if the actual remaining distance is less than the predicted required distance.

Abstract: A logic controlled take-off warning system having a circuit for enabling the logic controlled take-off warning system at engine thrust levels exceeding a predetermined value which is less than minimum take-off thrust of the aircraft and greater than trust required for normal ground operations, provided also that the aircraft is on the ground. When the logic controlled take-off warning system is enabled, a take-off warning horn is subsequently energized when any one of a plurality of undesired take-off configurations exists.

Abstract: Aircraft weight and balance computer apparatus processes sensor outputs to generate an electrical signal that is proportional to aircraft gross weight at the time take-off thrust is initially applied to the aircraft on the runway and continually updates the weight signal when airborne to account for burn off of fuel or other weight loss and also provides a measure of the location of the aircraft center of gravity position. This is achieved by computing the aerodynamic forces on the aircraft in its longitudinal plane and the thrust generated by the engines and relating these computations to the corresponding acceleration components measured by a pair of linear accelerometers that are mounted orthogonally in this longitudinal plane.

Abstract: The inventive system requires that normal approach indicated airspeed and a predetermined approach groundspeed be used as the approach criteria, whichever is the least, compared to its own predetermined index value. These two values are the commanding functions fed to a fast/slow indicator and to any auto-throttle device on the approach, along with a "caution tailwind" warning device to warn the pilot whenever the groundspeed exceeds true airspeed by 5 knots or more, for example. If this warning activates, he should consider cancelling the approach and choose an approach from a different direction, determined by surface wind and his drift at the time of cancellation. This condition is caused by a tailwind component at altitude, the value of which the pilot can determine from his airspeed and groundspeed indications.

Abstract: This apparatus generates a signal to control the vertical position of a horizontal bar indicator in a head-up display for viewing by the pilot of an aircraft so that the bar is superimposed on the pilot's view of the runway to assist him in controlling the pitch attitude of the aircraft during landing. The apparatus forms the bar control signal by operating on selected dynamic parameters of the aircraft to generate a lead compensation angle signal. A signal representative of the product of the lead compensation angle signal and a gain factor signal that is a function of the aircraft's altitude is summed to a signal representative of the glide path angle selected by the pilot to produce the desired bar control signal. In IFR conditions the bar may be superimposed with suitable flight director indications on the head-up display.

Abstract: A flight control type system which provides a tactile readout to the hand of a pilot for directing elevator control during both approach to flare-out and departure maneuvers. For altitudes above flare-out, the system sums the instantaneous coefficient of lift signals of a lift transducer with a generated signal representing ideal coefficient of lift for approach to flare-out, i.e., a value of about 30% below stall. Error signals resulting from the summation are read out by the noted tactile device. Below flare altitude, an altitude responsive variation is summed with the signal representing ideal coefficient of lift to provide error signal readout.

Abstract: Wind conditions along the projected flight path of an aircraft are measured and displayed. Wind velocity and direction at the aircraft and at the projected touchdown or takeoff point of the aircraft are compared and the existence of a wind gradient or wind shear line along the flight path is predicted. The possible presence of a wind shear line and the velocity differential there across is used, in cooperation with altitude and airspeed information and the performance characteristics of the aircraft, to determine whether the planned maneuver may be successfully completed under the instantaneously existing wind conditions.

Abstract: Flight path angle is displayed relative to the aircraft reference indicator in a unique display and aircraft control system particularly useful during approach operations. Flight path angle is computed as a function of vertical velocity of the aircraft and air speed. Angle of attack is displayed as an angle relative to the flight path angle and is derived by computing the difference between pitch and flight path angle. Thrust command is displayed vertically relative to the aircraft reference indicator while heading command is displayed laterally with respect to the aircraft reference indicator.

Abstract: By utilizing a radio altimeter in conjunction with a measure of the aircraft speed, landing gear position and flap position, an aircraft terrain warning system is made possible which provides a voice warning indicating that the aircraft is too low with respect to the terrain when the aircraft is above a predetermined speed. For aircraft speeds below the predetermined speed, a voice warning is provided when the aircraft is below a predetermined altitude with the landing gear up indicating that the aircraft is too low with the gear up and when the gear is down and the flaps are not in a landing position and the aircraft descends below a second predetermined altitude a voice warning is generated indicating that the aircraft is too low with flaps up.

Abstract: Visual altitude alerting indicator for the altimeter of an aircraft, manually settable at "Before Landing Check List" to alert the pilot through visual cues to the required safe altitudes he must remember to prevent flying below prescribed safe altitudes, and to the altitude where the pilot must apply power to level when landing. The indicator requires no electronic assistance or audio alarms that might confuse the pilot over the many audio alarms presently used on aircraft. The alerting indicator consists of a ring concentric with the pivot for the hands of the altimeter and center of the dial therefor and adjustably movable about the dial and has a series of indicating altitude pointers to be adjusted relative to the dial at "Before Landing Check List" to alert the pilot through visual cues to the altitude he has to remember to prevent flying below prescribed safe altitudes when landing.

Abstract: The inventive system requires that normal approach indicated airspeed and a predetermined approach groundspeed be used as the approach criteria, whichever is the least, compared to its own predetermined index value. These two values are the commanding functions fed to a fast/slow indicator and to any auto-throttle device on the approach, along with a "caution tailwind" warning device to warn the pilot whenever the groundspeed exceeds true airspeed by 5 knots or more, for example. If this warning activates, he should consider cancelling the approach and choose an approach from a different direction, determined by surface wind and his drift at the time of cancellation. This condition is caused by a tailwind component at altitude, the value of which the pilot can determine from his airspeed and groundspeed indications.

Abstract: A pilot guidance system that computes and displays pitch and speed steering commands is automatically operated during the post-takeoff climb (at specified times clocked from the start of the takeoff run), to present commands that assist the pilot in cutting (and later in restoring) thrust for a predetermined interval to reduce engine noise, and in guiding the aircraft in a safe, gentle climb over the proximate community. The specified times (unique for each model of aircraft, airport, runway and departure flight path), synchronize the thrust cutback interval with the boundaries of the community in line with chosen departure path.

Abstract: In an aircraft terrain warning system utilizing a radar altimeter wherein the rate of closure to the terrain is compared with the aircraft's altitude above the terrain to generate a warning signal when the closure rate is excessive for a particular altitude, the closure rate signal is limited and biased depending upon the aircraft's closure rate and configuration in order to significantly increase the time response of the system while at the same time reducing nuisance warnings. The amplitude limit on the closure rate signal is varied, above a predefined altitude, as a function of the closure rate signal in order to provide increased warning times at greater closure rates. Circuitry, responsive to the aircraft's flap positions, is also provided to alter the characteristics of rate limiter so as to provide warning parameters that more accurately reflect operating conditions at lower aircraft speeds.

Abstract: For use in an aircraft warning system which measures the descent below a radio glideslope and compares it with the aircraft's altitude above ground to generate a warning when the descent below glideslope exceeds predefined limits for a particular altitude, circuitry is provided to generate an advisory warning above a predefined altitude and a hard warning, or command to take immediate action, below the predetermined altitude.

Abstract: A semi-automatic takeoff flight control system for automatically capturing a predetermined takeoff pitch attitude at a predetermined pitch rate during the aircraft takeoff rotation maneuver. In response to the manual rotation command from the pilot, control circuitry generates a pitch rate command to the elevator, limited to the predetermined pitch rate. As the craft rotates to an intermediate pitch attitude less than the desired predetermined takeoff climb attitude, circuitry is included to provide a pitch attitude command with regard to the predetermined reference attitude, which by virtue of rate, displacement, and integral control provides asymptotic capture of the predetermined reference attitude.

Abstract: An apparatus for controlling the distance between a vehicle to which it is attached and a surface over which the the vehicle may be moving. The apparatus includes a cable and a sheet member which in a first mode is in contact with the surface but in a second mode is out of contact with the surface. Because of design, the sheet member induces a greater tension in the cable when in the second mode than when in the first mode; the increase in tension may be used to actuate a control or indicating devices on the vehicle to maintain the distance within desired limits.

Abstract: An aircraft instrument for warning the pilot that the aircraft is in an unsafe condition in proximity to the ground. The instrument has inputs representing aircraft configuration, flight condition with respect to the ground, and glide slope. Detector circuits process the inputs and give a warning of unsafe proximity to the ground. The boundary conditions for the warning are selected to avoid false warnings. A glide slope detector distinguishes between a valid glide slope signal and spurious signals, without need for pilot input.