Patent ID: 6906641
Filing Date: 2005-06-14
Classification: B64D,G01C,G05D

Abstract:
1. An apparatus for alerting a pilot of a rotary wing aircraft of proximity to terrain, the apparatus comprising: an input for receiving signals representative of a position of the aircraft, a flight path angle of the aircraft and a speed of the aircraft, and coupled to a database of stored terrain information; an output; a signal processing device, coupled to said input, and coupled to said output, for: (a) defining a look ahead distance; (b) defining a first alert envelope, indicative of a first severity of terrain threat, wherein boundaries of said first alert envelope are determined as a first function of the flight path angle, said look ahead distance, and a terrain floor boundary; wherein said terrain floor boundary comprises a function of an aircraft altitude and said speed; (c) defining a second alert envelope, indicative of a second severity of terrain threat, wherein boundaries of said second alert envelope are determined as a second function of the flight path angle, said look ahead distance and said terrain floor boundary; and (d) outputting an alert signal when a subset of the stored terrain information is located within the boundaries of at least one of said first and said second alert envelopes.