Aircraft terrain warning systems and methods

• US 7,064,680 B2
• Filed: 12/20/2002
• Issued: 06/20/2006
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Aviation Communications And Surveillance Systems, LLC
• Inventors: Reynolds, Zachary, Ridenour, Richard, Stone, Cyro, Rowlan, Stacey
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US10/326,544
• Publication Number:
  US 20060097895A1
• Time in Patent Office: 1,278 Days
• Field of Search: 340/961, 340/963, 340/970, 340/968, 701/9, 701/4, 701/14, 701/301, 342/65
• US Class Current: 340/961
• CPC Class Codes: B64D 45/04 Landing aids; Safety measures to prevent collision with earth's surface
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

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.

Claims

1. A computer program product for preventing controlled flight of an aircraft into terrain, the computer program product stored in a tangible medium and comprising machine-readable code for:

comparing a terrain avoidance profile with terrain information to determine whether a potential collision threat with terrain exists;

generating a warning alert signal if the potential collision threat with terrain does exist;

comparing a clear terrain profile with said terrain information to determine whether to end a terrain avoiding flight maneuver; and

generating a terrain clear signal if it is determined that the terrain avoiding flight maneuver is to be ended;

wherein the clear terrain profile comprises a horizontal projection of the aircraft in a direction of the aircraft before a terrain avoiding maneuver is executed.

2. The computer program product of claim 1 further including code for:

monitoring air traffic in an area proximate to the aircraft to determine whether a potential traffic collision threat exists; and

generating at least one of a traffic advisory or a resolution advisory when the potential traffic collision threat is determined to exist.

3. A computer program product for preventing controlled flight of an aircraft into terrain, the computer program product stored in a tangible medium and comprising machine-readable code for:

comparing a terrain avoidance profile with terrain information to determine whether a potential collision threat with terrain exists;

generating a warning alert signal if the potential collision threat with terrain does exist;

comparing a clear terrain profile with said terrain information to determine whether to end a terrain avoiding flight maneuver; and

generating a terrain clear signal if it is determined that the terrain avoiding flight maneuver is to be ended;

wherein the clear terrain profile comprises an algorithm that when processed identifies a projected area in a direction substantially parallel with the horizon and in front of the aircraft'"'"'s bearing.

4. The computer program product of claim 3 further including code for:

monitoring air traffic in an area proximate to the aircraft to determine whether a potential traffic collision threat exists; and

generating at least one of a traffic advisory or a resolution advisory when the potential traffic collision threat is determined to exist.