Patent ID: 9644990
Date: 2017-05-09
CPC Classifications: B64D,G01C,G05D,G08G

Claim:
1. A sink rate alert system for an aircraft, the system comprising: a radio altimeter configured to produce an aircraft altitude value; and a ground proximity warning system in signal communication with the radio altimeter and configured to: receive landing zone (LZ) information for an approaching landing zone; determine an elevated landing scenario based on the received aircraft position value and LZ information, the elevated landing scenario indicating that the aircraft is on an approach to land at a landing zone which is raised above surrounding terrain; adjust an upper boundary of a sink rate alert envelope by an amount proportional to LZ height information to define a modified sink rate alert envelope for the elevated landing scenario; receive sink rate information including an aircraft sink rate for the aircraft; generate a sink rate alert during the elevated landing scenario when the aircraft sink rate is outside the modified sink rate alert envelope; and output the sink rate alert to an output device.