Aircraft terrain warning systems and methods

Abstract

Methods and systems are disclosed for preventing aircraft collisions with forward looking terrain avoidance (FLTA) functionality based on a terrain avoidance profile used to evaluate potential terrain threats based on the projected flight path of an aircraft in flight, and a clear terrain profile to determine whether the terrain threat has been cleared. If the terrain avoidance profile conflicts with terrain, a collision threat may exist whereby the pilot is notified and a terrain avoidance maneuver is executed. During the terrain avoidance maneuver the clear terrain profile extends in a direction substantially parallel with the horizon at or near the present altitude of the aircraft to check whether it is safe to return to the previous flight path angle or otherwise end the terrain-avoiding maneuver. When the clear terrain profile no longer conflicts with the terrain threat, a terrain clear indicator is then issued to the pilot.