How about best glide AOA? 

We used an engine out AOA in the A-6.

Jeff 

Sent from my iPad

On Feb 9, 2014, at 3:29 PM, Charles Brown <browncc1@verizon.net> wrote:

I vote with Chris.  I've been an aerodynamicist at Boeing and at General Dynamics (now Lockheed Martin).  For a whole airplane (not just an airfoil section), to simplify all the complexity of wing root incidence, twist/washout and spanwise airfoil variations, normally the angle of attack that produces approximately zero lift on the whole airframe+wing is arbitrarily chosen as "zero".  And by the way, usually airplanes are designed with the wing tipped up slightly with respect to the fuselage (angle of incidence), so that at cruise conditions the fuselage deck angle (waterline) is approximately zero (level) while the wing is tipped up just enough to produce 1g lift (lift=weight).

I'm curious though, what does it matter for an AOA indicator?  Cruise angles of attack are absolutely uninteresting.  Stall warning at some angle of attack that's just a little shy of max lift coefficient is the only angle that you have to dial in properly, right?

Charley Brown

Posted for Chris Zavatson <chris_zavatson@yahoo.com>:
  
 Angle of attack can have a few different definitions.  If tied to airframe
or airfoil geometry then zero degrees can produce positive lift.  To keep the
math simple, the zero lift line is used.  By definition, when it is at zero
angle there is zero lift.  Any positive angle produces positive lift.  This
removes all the variables of the physical geometry such as washout and
incidence angles, etc.
 Down low and fast the 360 needs a lift coefficient of about 0.19 or about
1.9 degrees - referenced to the zero lift line.

 Chris Zavatson
 N91CZ
 360std
 http://www.n91cz.net/