Excessive sink rate warning system for aircraft

Abstract From the Canadian patent

In an aircraft ground proximity warning system that compares the rate of descent of an aircraft with its altitude above the terrain and in response thereto generates a warning signal when the aircraft's sink rate exceeds a predetermined limit for a particular altitude a first type of advisory voice, warning is generated for combinations of lesser descent rates and greater altitudes and a second type of imperative voice warning is generated for greater sink rates at lower altitudes where the danger of the aircraft impact with the terrain is more significant. In addition the repetition rate of the advisory, warning is increased as a function of increasing descent rate and the amplitude of the …