What are high alpha manuvers?
01-08-2009, 02:17 PM
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What are high alpha manuvers?
I have seen the phrase high alpha maneuvers used quite often but not an explanation of just what it means.
Thanks in advance for your reply.
Thanks in advance for your reply.
01-08-2009, 04:26 PM
#4
RE: What are high alpha manuvers?
The plane is "flying" from the deflection of air not from lift of the airfoil. The wing is past the critical stall angle, so it is about horsepower and deflecting the air for control and lift.
01-08-2009, 05:33 PM
#5
RE: What are high alpha manuvers?
The little Greek letter "alpha" in the above diagram, and in aeronautics in general, is used to define the angle of attack - wing incedence angled from the horizontal (relative wind - NOT the ground).
In the image below the aircraft is climbing but the alpha is half the pitch ( "nose up") angle from horizontal.
"High alpha" indicates the nose is very up relative to the aircraft's vector of travel. A side effect is that the wing is stalled.
The wing is stalled in a flat-spin or inverted flat-spin but that's not a "high aplha" maneuver.
01-09-2009, 01:56 PM
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RE: What are high alpha manuvers?
Well done CharlieP. It's about the wing chord and VECTOR of travel. Not relative to the horizontal.
Pulling up from a steep dive is a high aoa move.
Pulling up from a steep dive is a high aoa move.
01-09-2009, 10:21 PM
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RE: What are high alpha manuvers?
Hialpha was a 12th century Hindu prophet. It was said that he could obtain such a trancendental state that he could actually levitate.
01-10-2009, 12:02 AM
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RE: What are high alpha manuvers?
ORIGINAL: Charlie P.
The little Greek letter "alpha" in the above diagram, and in aeronautics in general, is used to define the angle of attack - wing incedence angled from the horizontal (relative wind - NOT the ground).
In the image below the aircraft is climbing but the alpha is half the pitch ( "nose up") angle from horizontal.
"High alpha" indicates the nose is very up relative to the aircraft's vector of travel. A side effect is that the wing is stalled.
The wing is stalled in a flat-spin or inverted flat-spin but that's not a "high aplha" maneuver.
The little Greek letter "alpha" in the above diagram, and in aeronautics in general, is used to define the angle of attack - wing incedence angled from the horizontal (relative wind - NOT the ground).
In the image below the aircraft is climbing but the alpha is half the pitch ( "nose up") angle from horizontal.
"High alpha" indicates the nose is very up relative to the aircraft's vector of travel. A side effect is that the wing is stalled.
The wing is stalled in a flat-spin or inverted flat-spin but that's not a "high aplha" maneuver.
01-10-2009, 12:15 AM
#9
RE: What are high alpha manuvers?
Good question. But I think hovering is still hgh alpha as the nose is up and the relative wind is certainly not from "nose on" if the aircraft is static relative to the vertical. If it is drifting in any horizontal direction (mine always do) then the relative wind is perpendicular to the longitudinal axis and it qualifies as high alpha.
That's my story and I'm sticking to it.
That's my story and I'm sticking to it.
01-10-2009, 12:18 AM
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RE: What are high alpha manuvers?
[/quote]
Technically this means that hovering is not a high alpha maneuver. Right?
[/quote]
That statement is only true when the airplane is perfectly vertical and there is no control inputs, most of the time it is in high AoA but occasionally its not.
Steven
