Composite normalized angle of attack indicating system
View Patent ↗A composite normalized angle of attack indicating system provides a simultaneous display of both body angle of attack, such as in digital form, and normalized angle of attack for an aircraft. The display may be visually enhanced as stall is approached such as by zooming the body angle of attack digital display and/or by changing the color of the display. The normalized display also selectively displays an approach reference band when the flap setting is equal to or greater than 20 degrees.
1. A normalized angle of attack indicating system for use in an aircraft comprising:
a display gauge having fixed position markings to indicate a predetermined range of normalized aircraft angle of attack in a normalized display presentation, said predetermined range comprising a zero body angle of attack and a stall angle of attack with respect to said aircraft, said display gauge comprising means for displaying said predetermined range in said normalized display presentation;
means for selectively displaying an approach reference band for said aircraft in said normalized display presentation when said fixed position markings correspond to a predetermined percentage of said stall angle of attack; and
means for displaying a displayable indicia of body angle of attack for said aircraft simultaneously with said normalized angle of attack for said aircraft on said display gauge for providing a composite simultaneous display of said body angle of attack along with said normalized angle of attack for said aircraft, said body angle of attack being dependent on specific constants for said aircraft.
2. An indicating system in accordance with claim 1 wherein said body angle of attack displayable indicia comprises a digital display of said body angle of attack.
3. An indicating system in accordance with claim 2 wherein said normalized angle of attack display presentation comprises a movable pointer indicia and a scale comprising said fixed position markings, said pointer indicia being movable along said scale between said fixed position markings in accordance with changes in said normalized angle of attack.
4. An indicating system in accordance with claim 3 wherein said scale comprises a plurality of scale segments, said scale segments comprising a typical flight area segment, a stick shaker angle of attack segment, and an approach angle of attack segment.
5. An indicating system in accordance with claim 4 wherein said scale segments further comprise a scale segment based on said zero body angle of attack and a scale segment based on said stall angle of attack.
6. An indicating system in accordance with claim 5 further comprising means for enhancing said body angle of attack display presentation in response to a predetermined condition.
7. An indicating system in accordance with claim 6 wherein said predetermined condition comprises said body angle of attack value approaching said stall value for said aircraft.
8. An indicating system in accordance with claim 7 wherein said enhancing means further comprises means for dynamically zooming said body angle of attack display presentation in response to said predetermined condition.
9. An indicating system in accordance with claim 8 wherein said enhancing means further comprises means for changing coloration of said body angle of attack display presentation in response to said predetermined condition.
10. An indicating system in accordance with claim 9 wherein said normalized scale is based on the equation
n
=
α
-
α
APP
α
SS
-
α
APP
*
-
90
where α represents the angle of attack
α App represents the approach reference angle of attack,
and α ss represents the stick shaker angle of attack.
11. An indicating system in accordance with claim 1 wherein said body angle of attack displayable indicia comprises a digital display of said body angle of attack.
12. An indicating system in accordance with claim 11 wherein said normalized angle of attack display presentation comprises a movable pointer indicia and a scale comprising said fixed position markings, said pointer indicia being movable along said scale between said fixed position markings in accordance with changes in said normalized angle of attack.
13. An indicating system in accordance with claim 1 wherein said normalized angle of attack display presentation comprises a movable pointer indicia and a scale comprising said fixed position markings, said pointer indicia being movable along said scale between said fixed position markings in accordance with changes in said normalized angle of attack.
14. An indicating system in accordance with claim 13 wherein said scale comprises a plurality of scale segments, said scale segments comprising a typical flight area segment, a stick shaker angle of attack segment, and an approach angle of attack segment.
15. An indicating system in accordance with claim 14 wherein said scale segments further comprise a scale segment based on said zero body angle of attack and a scale segment based on said stall angle of attack.
16. An indicating system in accordance with claim 1 further comprising means for enhancing said body angle of attack display presentation in response to a predetermined condition.
17. An indicating system in accordance with claim 16 wherein said predetermined condition comprises said body angle of attack value approaching said stall value for said aircraft.
18. An indicating system in accordance with claim 17 wherein said enhancing means further comprises means for dynamically zooming said body angle of attack display presentation in response to said predetermined condition.
19. An indicating system in accordance with claim 18 wherein said enhancing means further comprises means for changing coloration of said body angle of attack display presentation in response to said predetermined condition.
20. An indicating system in accordance with claim 17 wherein said enhancing means further comprises means for changing coloration of said body angle of attack display presentation in response to said predetermined condition.
21. An indicating system in accordance with claim 1 wherein said normalized angle of attack display presentation comprises a scale comprising said fixed position markings, said normalized scale being based on the equation
n
=
α
-
α
APP
α
SS
-
α
APP
*
-
90
where α represents the angle of attack
α App represents the approach reference angle of attack,
and α ss represents the stick shaker angle of attack.