Windshear detection and warning system

Claim 2

Windshear detection and warning apparatus for aircraft characterised in that it comprises means (41) for providing signals proportional to the magnitude of the vector values of the inertial vertical (a V ) and horizontal acceleration (a H ) of the aircraft, means (44) responsive to said acceleration signals for providing a signal proportional to the product of magnitude and rate of rotation of the vector value of the resultant inertial acceleration of the aircraft, and windshear warning means (44, 52) responsive to values of the product signal in excess of a predetermined value.

Claim 3

Apparatus according to claim 1, characterised in that the windshear warning means comprises means for providing a warning of moderate windshear conditions, means for providing a warning of severe windshear conditions, and windshear detection means for detecting values of the product signal of one sense for operating the moderate windshear condition warning means, and for detecting values of the product signal in the opposite sense for operating the severe windshear warning means.

Claim 4

Apparatus according to claim 2, characterised in that it further comprises air data computer means (47) for providing signals proportional to the vertical and horizontal acceleration of the aircraft relative to its sustaining air mass, comparator means (88, 96) responsive to the inertial and air mass vertical and horizontal acceleration signals, respectively, and for supplying corresponding windshear alert signals when their respective differences exceed a predetermined value, means (C, D, E) for arming the moderate and severe windshear warning means, for operation by the windshear warning signal, and means (91, 99) responsive to the alert signals for arming the arming means.

Claim 5

Apparatus according to claim 3, characterised in that it further comprises means responsive to the inertial and air mass vertical and horizontal acceleration signals, respectively, and for supplying corresponding windshear warning signals proportional to the rate of change of their respective differences in one sense and an opposite sense, and means responsive to the arming means for supplying the rate of change signals of one sense to the moderate windshear warning means, and of the opposite sense to the severe windshear warning means.

Claim 6

Windshear detection and warning apparatus for aircraft characterised in that it comprises means for providing a plurality of separate signals which vary in accordance with the vertical and horizontal acceleration of the aircraft relative to the ground, means for providing a plurality of separate signals which vary in accordance with the vertical and horizontal acceleration of the aircraft relative to the sustaining air mass, means for separately comparing the receptive acceleration signals, and windshear detection means responsive to any disparity between one or more of the compared signals.

Claim 7

Windshear detection and warning apparatus for aircraft characterised in that it comprises means for providing a plurality of separate signals which vary in accordance with the vertical and horizontal acceleration of the aircraft relative to the ground, means for providing a plurality of separate signals which vary in accordance with the vertical and horizontal acceleration of the aircraft relative to the sustaining air mass, means for separately comparing the receptive acceleration signals, and windshear detection means responsive to any disparity between one or more of the compared signals.

Claim 8

Apparatus according to claim 5, characterised in that it further comprises means responsive to the comparing means for providing separate signals proportional to the rate of change of any discrepancy between the compared signals, and means for supplying the rate of change signals to the windshear detection means.

Claim 9

Apparatus according to claim 6, characterised in that the ground referenced vertical and horizontal acceleration component signals represent corresponding vector components of the total aircraft acceleration vector relative to the ground, and in that the apparatus further comprises means responsive to the ground referenced acceleration component signals for supplying a signal proportional to the product of the magnitude and rate of rotation of the total aircraft acceleration vector, and means for supplying the product signal to the windshear detection means.

Claim 10

Apparatus according to claim 7, characterised in that it further comprises moderate and severe windshear warning means, and means responsive to the product signal of one sense for operating the moderate windshear warning means, and of the opposite sense for operating the severe windshear warning means.

Claim 11

Windshear detector and warning apparatus for aircraft characterised in that it comprises means for comparing signals proportional to the vertical and horizontal vector components of aircraft acceleration relative to the ground and relative to the sustaining air mass, respectively, means responsive to the comparing means for providing signals proportional to any discrepancy between the compared signals and for providing a first windshear warning characteristic upon either of them exceeding a predetermined value, further means responsive to the compared signals for providing signals proportional to the rate of change of any discrepancy therebetween, and means responsive to the first windshear warning characteristic and the rate of change signals for providing a second windshear warning characteristic upon either of the rate of change signals exceeding a predetermined value.

Claim 12

Windshear detector and warning apparatus for aircraft characterised in that it comprises means for comparing signals proportional to the vertical and horizontal vector components of aircraft acceleration relative to the ground and relative to the sustaining air mass, respectively, means responsive to the comparing means for providing signals proportional to any discrepancy between the compared signals and for providing a first windshear warning characteristic upon either of them exceeding a predetermined value, further means responsive to the compared signals for providing signals proportional to the rate of change of any discrepancy therebetween, and means responsive to the first windshear warning characteristic and the rate of change signals for providing a second windshear warning characteristic upon either of the rate of change signals exceeding a predetermined value.

Claim 13

Apparatus according to claim 9, characterised in that it further comprises means responsive to the signals proportional to the vertical and horizontal vector components of aircraft acceleration relative to the ground for providing a signal which varies in accordance with the magnitude and the rate of rotation of the vector resultant of the component acceleration vectors, and means responsive to the first windshear warning characteristic and the magnitude and rate of rotation signal for providing the second warning characteristic when the magnitude and rate of rotation signal exceeds a predetermined value.

Claim 14

Apparatus according to claim 10, characterised in that it further comprises armable means responsive to the rate of change and the magnitude and rate of rotation signals for operating, when armed, the second windshear warning characteristic providing means, and timing means responsive to the discrepancy signals for arming the arming means for a predetermined time period subsequent to either of the discrepancy signals exceeding the predetermined value.

Claim 15

Windshear detection and warning apparatus for an aircraft having flight control instrumentation responsive to normal command signals for directing the aircraft along a predetermined flight path, characterised in that the apparatus comprises means responsive to signals which vary in accordance with the vertical and horizontal components of aircraft acceleration relative to the ground and relative to the sustaining air mass for providing windshear warning signals proportional to deviations in excess of a predetermined value between the vertical components of the ground and air mass acceleration signals, and between the horizontal components of the ground and air mass acceleration signals, means responsive to the angle of attack of the aircraft for providing a command signal corresponding to the maximum safe angle of attack of the aircraft, switching means for removing the normal command signal from the control instrumentation and for supplying the angle of attack command signal thereto, and means responsive to the windshear warning signal for signalling the operation of the switching means.

Claim 16

Windshear detection and warning apparatus for an aircraft having flight control instrumentation responsive to normal command signals for directing the aircraft along a predetermined flight path, characterised in that the apparatus comprises means responsive to signals which vary in accordance with the vertical and horizontal components of aircraft acceleration relative to the ground and relative to the sustaining air mass for providing windshear warning signals proportional to deviations in excess of a predetermined value between the vertical components of the ground and air mass acceleration signals, and between the horizontal components of the ground and air mass acceleration signals, means responsive to the angle of attack of the aircraft for providing a command signal corresponding to the maximum safe angle of attack of the aircraft, switching means for removing the normal command signal from the control instrumentation and for supplying the angle of attack command signal thereto, and means responsive to the windshear warning signal for signalling the operation of the switching means.

Claim 17

Apparatus according to claim 12, characterised in that the aircraft also has an automatic throttle control system for the aircraft engines responsive to normal command signals for maintaining aircraft speed at a predetermined value, and in that the apparatus further includes means for supplying a command signal corresponding to the maximum safe thrust for the engines, and further switching means for removing the normal command signal from the throttle control system and for supplying the maximum thrust command signal thereto, the further switching means being also operative in response to the windshear warning signalling means

Claim 18

Apparatus according to claim 12 or 13, characterised in that the windshear warning signals further include components proportional to the rate of change of the deviations between the vertical and horizontal components of the ground and air mass acceleration signals.

Claim 19

Apparatus according to claim 12 or 13, characterised in that the windshear warning signals further include a component proportional to the magnitude and rate of rotation of the resultant acceleration vector of the vertical and horizontal components of the ground acceleration signals.