초록 ▼

A windshear warning system having an adjustable threshold to avoid triggering nuisance windshear alerts wherein the magnitude and duration of the shear are not sufficient to endanger an aircraft that is flying a landing approach at greater-than-normal approach speed. The present invention provides f

A windshear warning system having an adjustable threshold to avoid triggering nuisance windshear alerts wherein the magnitude and duration of the shear are not sufficient to endanger an aircraft that is flying a landing approach at greater-than-normal approach speed. The present invention provides for variable detection times in either a variable threshold windshear detection or a fixed threshold detection system. A measurement of angle or attack is used to deduce the aircraft\s approximate weight from which a normal landing approach speed may be calculated. The difference between the computed landing approach speed and the actual approach speed is used to calculate an add-on differential to the windshear system detection threshold. The add-on factor and a predetermined timing factor dependent on the power-to-weight ratio of the aircraft are combined to derive a new timing value for a variable threshold warning system which delays the windshear alert based on the magnitude of the windshear and the increase over the normal approach speed.

대표청구항 ▼

In a windshear warning system for aircraft of the type including threshold detector means responsive to the magnitude of a windshear signal exceeding a predetermined threshold of detection, first timer means activated by said threshold detector means for providing a first timing signal proportional

In a windshear warning system for aircraft of the type including threshold detector means responsive to the magnitude of a windshear signal exceeding a predetermined threshold of detection, first timer means activated by said threshold detector means for providing a first timing signal proportional in magnitude to the duration of the windshear rate signal after said detector means is activated, second timer means activated by said threshold detector means for generating a second timing signal representative of a maximum allowable duration that the aircraft may be sustained in safe flight at a given windshear rate, and means for algebraically summing said first and second timing signals and for generating a windshear warning signal when said first timing signal exceeds said second timing signal, wherein said second timer means further comprises: differential speed computation means responsive to a source of signals representative of flap position, angle of attack, calibrated air speed, and normal acceleration, for generating a signal corresponding to weight of the aircraft means responsive to said weight signal and said flap position signal for deriving a stall speed signal representative thereof, means for applying a predetermined multiplier to said stall speed signal for deriving a normal approach speed signal proportional to the product thereof, means for applying said signal representative of calibrated airspeed to said normal approach signal to derive a speed additive signal representative of the difference between said normal approach speed signal and said calibrated air speed signal, means for providing a signal corresponding to a predetermined power/weight ratio of the aircraft, and means for combining said speed additive signal, said power/weight signal, and said windshear rate signal to derive said second timing signal, and means for algebraically summing said first and second timing signals and generating a windshear warning signal when said first timing signal exceeds said second timing signal in a positive sense without manual intervention by the pilot.