Windshear detection and warning system with evasion command

Claim 2

Apparatus for generating a windshear warning control signal, of the type having detector means for sensing the difference of aircraft inertial acceleration with respect to a supporting airmass, and providing vertical or longitudinal components thereof, comprising: means responsive to said difference of inertial acceleration for providing a windshear rate signal representative of a magnitude of windshear rate exceeding a predetermined limit corresponding to a threshold of detection, means responsive to said windshear rate signal exceeding said predetermined limit for providing a first timing signal representative of a time duration of said rate signal, means responsive to said windshear rate signal for generating a second timing signal representative of a maximum allowable duration that safe flight can be sustained at said windshear rate, and means for combining said first timing signal and said second timing signal to obtain an algebraic difference thereof and generate said control signal when said first timing signal exceeds said second timing signal, so that said warning signal is generated after a time delay inversely as the magnitude of said windshear rate signal.

Claim 3

The apparatus as set forth in claim 1, further comprising: means for providing a signal corresponding to a predetermined value of an aircraft parameter representative of a power-to-weight ratio, and means for applying said aircraft parameter signal to said windshear rate signal for deriving said second timing signal.

Claim 4

The apparatus as set forth in claim 2, further comprising detection means responsive to the magnitude and polarity of said control signal for generating a windshear annunciation signal when said first timing signal has a value exceeding said second timing signal.

Claim 5

The apparatus as set forth in claim 3, wherein said means for generating a windshear annunciation signal further comprises: means responsive to the magnitude of said windshear rate signal for providing a signal having a first logic condition when a predetermined value of said magnitude is exceeded, and a second logic condition when said predetermined value is not exceeded, said first timing means is responsive to said logic signals and indicative of a time interval corresponding to a change in state between said second and first logic conditions, and said means for generating said second timing signal comprises divider means having an output indicative of a time duration comprising the quotient of said aircraft parameter signal and said magnitude of windshear rate signal.

Claim 6

The apparatus as set forth in claim 4, wherein said windshear rate signal comprises vertical components of a total acceleration vector representative of the resultant sum of said vertical and horizontal inertial acceleration components of said aircraft.

Claim 7

The apparatus as set forth in claim 4, wherein said windshear rate signal comprises longitudinal components of said total acceleration vector.

Claim 8

The apparatus as set forth in claim 4, wherein said windshear rate signal comprises vertical and longitudinal components of said total acceleration vector.

Claim 9

A windshear detection circuit for providing a signal representative of the magnitude and duration of a windshear disturbance, of the type providing vertical and longitudinal rate components derived by processing air data acceleration signals corresponding to aircraft inertial acceleration and accelertion relative to a surrounding air mass comprising: threshold detector means responsive to one of said rate components for providing an output signal when said one rate component exceeds a predetermined threshold, timer means coupled to said threshold detector means to provide a signal indicative of a duration of said output signal, means proportional to a power-to-weight ratio of said aircraft for providing a signal representative of an aircraft performance parameter, divider means responsive to said rate component and said parameter signal for providing a quotient signal thereof, means responsive to said quotient signal for providing a signal indicative of the absolute magnitude thereof, means for combining said duration signal and said absolute magnitude signal for providing an algebraic difference thereof, and means responsive to said algebraic difference for providing a signal indicative of the polarity thereof.

Claim 10

A windshear detection circuit for providing a signal representative of the magnitude and duration of a windshear disturbance, of the type providing vertical and longitudinal rate components derived by processing air data acceleration signals corresponding to aircraft inertial acceleration and accelertion relative to a surrounding air mass comprising: threshold detector means responsive to one of said rate components for providing an output signal when said one rate component exceeds a predetermined threshold, timer means coupled to said threshold detector means to provide a signal indicative of a duration of said output signal, means proportional to a power-to-weight ratio of said aircraft for providing a signal representative of an aircraft performance parameter, divider means responsive to said rate component and said parameter signal for providing a quotient signal thereof, means responsive to said quotient signal for providing a signal indicative of the absolute magnitude thereof, means for combining said duration signal and said absolute magnitude signal for providing an algebraic difference thereof, and means responsive to said algebraic difference for providing a signal indicative of the polarity thereof.

Claim 11

Windshear detection and warning apparatus for aircraft comprising: means for providing a signal proportional to a total acceleration vector representative of an inertial acceleration of the aircraft with respect to ground independent of pitch or roll of the aircraft, means for determining the rate and direction of rotation of said total acceleration vector, means for determining the magnitude of said total acceleration vector, means for providing a signal proportional to the product of said magnitude and said rate of rotation of said total acceleration vector, and warning means responsive to values of said product signal in excess of a predetermined value.

Claim 12

Windshear detection and warning apparatus for aircraft comprising: means for providing a signal proportional to a total acceleration vector representative of an inertial acceleration of the aircraft with respect to ground independent of pitch or roll of the aircraft, means for determining the rate and direction of rotation of said total acceleration vector, means for determining the magnitude of said total acceleration vector, means for providing a signal proportional to the product of said magnitude and said rate of rotation of said total acceleration vector, and warning means responsive to values of said product signal in excess of a predetermined value.

Claim 13

Apparatus as set forth in claim 9 for determining the magnitude and rate of change of direction of said total acceleration vector of the aircraft wherein said total acceleration vector is comprised of horizontal and vertical vector components, further comprising: first sensor means mounted rigidly to said aircraft with a sensing axis normal to a longitudinal axis of said aircraft to sense accelerations along said longitudinal axis, second sensor means mounted rigidly to said aircraft in a plane normal to said longitudinal axis to sense accelerations normal to said longitudinal axis, means for determining the pitch and bank attitude of the aircraft relative to an earth's gravity vector, and data processor means responsive to said first and second sensors and said pitch and bank attitude determining means for generating signals proportional to the magnitude and direction of said total acceleration vector and to said horizontal and vertical components.

Claim 14

Windshear detection and warning apparatus as set forth in claim 10, further comprising: means for providing a signal proportional to the rate of change of true forward speed of the aircraft in a supporting airmass, means responsive to a horizontal acceleration vector component signal and said rate of change of true forward speed signal for providing a signal proportional to an algebraic difference thereof, and means for providing said difference signal to said warning means for activating said warning means when said difference signal exceeds a predetermined value indicative of a horizontal windshear.

Claim 15

Windshear detection and warning apparatus as set forth in claim 11, further comprising: means for providing a signal proportional to the rate of change of vertical airspeed of the aircraft relative to said supporting air mass, means responsive to a vertical acceleration vector component and said rate of change of vertical airspeed signal for providing a signal proportional to an algebraic difference thereof, and means for providing said difference signal to said warning means for activating said warning means when said difference signal exceeds a further predetermined value indicative of a vertical windshear.

Claim 16

Apparatus as set forth in claim 12 for indicating a moderate windshear condition, comprising: means responsive to said rate of rotation of said total acceleration vector for providing a signal indicative of a downburst, means responsive to said signal proportional to an algebraic difference of said horizontal acceleration vector component and said rate of change of true forward speed for providing a signal indicative of a headwind windshear, means responsive to said signal proportional to an algebraic difference of said vertical acceleration vector and said rate of change of vertical airspeed signal for providing a signal indicative of an updraft, means for activating said warning means when at least one of said downburst signal, said headwind windshear signal, and said updraft signal exceeds a predetermined value for a predetermined time interval, and means for combining said predetermined value and said predetermined time interval to provide a signal indicative of a moderate windshear condition.

Claim 17

Apparatus as set forth in claim 12 for indicating a severe windshear comprising: means responsive to said rate of rotation of said total acceleration vector for providing a first signal indicative of a downburst, means responsive to said signal proportional to an algebraic difference of said horizontal acceleration vector component and said rate of change of true forward speed for providing a signal indicative of a tailwind windshear, means responsive to said signal proportional to an algebraic difference of said vertical acceleration vector and said rate of change of vertical airspeed for providing a second signal indicative of a downburst, and means for activating said warning means when at least one of said tailwind windshear signal and said first and second downburst signals exceeds a predetermined value for a predetermined time interval indicative of a severe windshear condition.