An electro-optical flight instrument is provided which accepts input signals from appropriate sensors and transducers on an aircraft to provide a visual display of the pitch angle of the aircraft, the visual display being established by means of a transparent screen positioned in the pilot's normal line of sight and focused at infinity. A servo reticle is driven in the instrument and is projected at infinity upon the transparent screen, the servo reticle displaying in degrees, the angle between the aircraft and the horizon.

A flight data display system providing the visual display of luminous markers which comprise, in particular, a fixed marker for indicating a reference incidence angle, a movable marker for indicating the instantaneous incidence angle detected by a sensor, and a movable marker indicating a reference slope angle. The amplitude and the sign of the reference slope angle are manually selected by the pilot by controlling the cursor of a potentiometer and by acting a voltage inverter. The system is applicable to all aircraft and can be utilized in all phases of flight, in particular for the landing, since the pilot can easily determined the top of descent point (alignment of the slope marker with the runway threshold), and observe that correct glide slope and incidence angle are maintained during the approach.

An aircraft instrument providing visual flight path guidance to the pilot during landing approach, to clear an obstacle or the like. A head-up collimated display has a transverse bar positioned in accordance with a signal representing the angle of attack of the aircraft, with a corrective bias, which indicates to the pilot the flight path of the aircraft. The display includes a vertical scale positioned with respect to a horizontal reference, indicating to the pilot the angle of the path from the aircraft to a point on the ground. The angle of attack signal displayed by the bar is biased by a signal derived from the rate of change of flight path of the aircraft to compensate for the effect of errors, as caused by winds having a component in the vertical plane containing the flight path. Synthetic signals are developed for various flight conditions minimizing errors due to air mass movement and inherent inaccuracies of condition sensors.

A display instrument for projecting aircraft flight data upon a transparent screen into the pilot's normal line of sight, wherein an optical objective projects images of luminous objects focused at infinity onto a combining glass; the luminous objects which represent the flight data to be displayed being carried out by means of electro-optical transducers such as electroluminescent diodes supplied by an associated supply circuit; servo means responsive to output signals of airborne sensor devices controlling the displacement of, and the selective supply to, the diodes representative of variable flight data.

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.