Ground proximity warning system for use with aircraft having egraded performance

Claim 1

An aircraft ground proximity warning system comprising: a source of radio altitude signals; means for generating a flight path angle signal; warning means responsive to said flight path angle signal for generating a warning signal when said flight path angle signal is less than a predetermined value; a source of barometric altitude rate signals; wherein said means for generating said flight path angle signal is responsive to said barometric rate signal such that said flight path angle signal is proportional to said barometric rate signal; a source of radio rate signals; computed altitude rate means for combining said barometric altitude rate signal and said radio altitude rate signal to obtain a computed altitude rate signal wherein said computed altitude rate signals include a greater proportion of said radio altitude rate signals as radio altitude decreases; and wherein said flight path angle signal is proportional to said computed altitude rate signal.

Claim 12

A system for providing the pilot of an aircraft with a warning of abnormal aircraft performance comprising: a source of signals representative of the airspeed of the aircraft; means for providing a signal representative of the normal deceleration profile of the aircraft; means responsive to said airspeed representative signals and said deceleration profile signal providing means for generating a warning as the deceleration of the aircraft exceeds the normal deceleration profile by a predetermined amount; and a source of signals representative of the deviation below the glideslope of the aircraft, wherein said deceleration profile of the aircraft is responsive to said glideslope deviation signal for defining said deceleration profile as a function of glideslope deviation.

Claim 13

A system for providing the pilot of an aircraft with a warning of abnormal aircraft performance comprising: a source of signals representative of the airspeed of the aircraft; means for providing a signal representative of the normal deceleration profile of the aircraft; means responsive to said airspeed representative signals and said deceleration profile signal providing means for generating a warning as the deceleration of the aircraft exceeds the normal deceleration profile by a predetermined amount; and a source of signals representative of the deviation below the glideslope of the aircraft, wherein said deceleration profile of the aircraft is responsive to said glideslope deviation signal for defining said deceleration profile as a function of glideslope deviation.

Claim 14

A system for providing an advisory message to a pilot of an aircraft upon take off in the presence of degraded performance comprising: a source of signals representative of the airspeed of the aircraft; means responsive to the airspeed signal for providing a degraded performance message in the event that the airspeed decreases at a predetermined rate; means for providing a signal representative of the angle of attack of the aircraft; means for providing a signal representative of the stall angle of the aircraft; and means responsive to said airspeed signal and to the difference between the angle of attack signal and the stall angle representative signal for providing an advisory message to the pilot that the stall angle exceeds the angle of attack by a predetermined amount and the decrease in airspeed equals or exceeds said predetermined rate.

Claim 15

A system for providing an advisory message to a pilot of an aircraft upon take off in the presence of degraded performance comprising: a source of signals representative of the airspeed of the aircraft; means responsive to the airspeed signal for providing a degraded performance message in the event that the airspeed decreases at a predetermined rate; means for providing a signal representative of the angle of attack of the aircraft; means for providing a signal representative of the stall angle of the aircraft; and means responsive to said airspeed signal and to the difference between the angle of attack signal and the stall angle representative signal for providing an advisory message to the pilot that the stall angle exceeds the angle of attack by a predetermined amount and the decrease in airspeed equals or exceeds said predetermined rate.

Claim 19

A system for advising the pilot of an aircraft of a dangerous loss of altitude close to the ground of the type that can be caused by a wind shear condition without actually measuring wind shear, comprising: means for receiving a signal representative of the altitude of the aircraft; means for receiving a signal representative of the rate of change of altitude of the aircraft; means for receiving a signal representative of the rate of change of airspeed of the aircraft; means for receiving a signal representative of the flight path angle of the aircraft; and means responsive to said altitude, altitude rate, airspeed rate and flight path angle signal receiving means for generating a signal according to a predetermined relationship between the altitude, altitude rate, airspeed rate and flight path angle to advise the pilot of a loss of altitude condition.

Claim 20

A system for advising the pilot of an aircraft of a dangerous loss of altitude close to the ground of the type that can be caused by a wind shear condition without actually measuring wind shear, comprising: means for receiving a signal representative of the altitude of the aircraft; means for receiving a signal representative of the rate of change of altitude of the aircraft; means for receiving a signal representative of the rate of change of airspeed of the aircraft; means for receiving a signal representative of the flight path angle of the aircraft; and means responsive to said altitude, altitude rate, airspeed rate and flight path angle signal receiving means for generating a signal according to a predetermined relationship between the altitude, altitude rate, airspeed rate and flight path angle to advise the pilot of a loss of altitude condition.