An air data computer outputs a data stream indicative of measured airspeed of an aircraft, for use in generating a display of airspeed to a pilot. To correct for the inherent processing delay, a correction factor is added to the data stream, so that the display is more closely related to the actual airspeed of the aircraft at the time of the display. The correction factor can be calculated by determining the average rate of change of airspeed during a preceding time interval and multiplying the average rate of change by the processing delay.

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. The invention is self-adaptive since the pitch limit varies in response to changes in the ground speed of the aircraft, wind, and ILS beam angles.

The present invention improves upon conventional windshear data processing techniques in three mutually exclusive aspects. First, the present invention provides an improved method and system for detecting microburst downdraft candidates. The improvement lies in its capability of detecting multiple candidates in range. Because of the added capability to detect multiple candidates in range, the present invention also provides an improved method and system for azimuthal association of the multiple candidates in range to define an accurate locus of headwind and tailwind pairs. Second, the present invention provides an improvement in that it utilizes a non-circularly symmetric spatial model to compute the vertical component of a total hazard factor. Third, the present invention provides an improvement in the accurate detection of small radii microbursts by correcting bias present in the data from which the small radii microbursts may be detected.

A method of detecting a windshear hazard on aircraft is disclosed. The method includes determining a first wind velocity of the aircraft at the location of the aircraft using a wind velocity detector. The method also includes determining a second wind velocity at a distance ahead of the aircraft using a forward-looking wind velocity detection system onboard the aircraft. Further, the method comprises determining the wind velocity gradient over the distance and determining whether windshear hazard exists for the aircraft.