[Don't forget that you can stall an airplane at almost any airspeed, but the critical angle of attack at which the wing stalls will always be the same.  While 80-90 knots might be a "safe" airspeed flying straight & level & lightly loaded, if you increase the wing loading with a 60 degree bank (or simply load up with full tanks & baggage), your 80-90 knots might just not be so safe anymore.  If you go to http://www.advanced-flight-systems.com/Support/AOAsupport/AOA%20Manual%20rev4.pdf and scroll down to page 17 (The "How it works" chapter) you'll have a better understanding of the "gotchas" that conventional flight training has always danced around concerning AOA.  Just my $0.02.   <marv>   ]

>  _____  
>
>From: Douglas Brunner [mailto:douglasbrunner@earthlink.net]
> Sent: Sunday, March 30, 2014 3:35 PM
> To: lml@lancaironline.net
> Subject: RE: [LML] Re: FW: Adding an AOA
>
>
>
> Terrence,
>
>
>
> There is no "angle" to mark.  Both instruments use an array of colored
> lights -  in both, the top colored light is a red arrow pointing down -
> presumably this is to indicate a stall.
>
>
>
> The way that both are made to be used is to define a safe speed (roughly 1.3
> Vso) that can be used during landing (and other maneuvers)
>
>
>
> My question was whether to set it to 1.3 Vso or to do the maneuver described
> in the setup.
>
>
>
> D. Brunner
>
>
>
>From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of
> Terrence O'Neill
> Sent: Sunday, March 30, 2014 2:18 PM
> To: lml@lancaironline.net
> Subject: [LML] Re: FW: Adding an AOA
>
>
>
> D.,
>
>
>
> IMHO the prime purpose of an AOA is:
>
>
>
> To make the wing's STALL  ANGLE visible to the pilot.  You do that by flying
> the plane and stalling it as you watch the AOA... then mark that angle.
>
> The next most useful AOA info is the best L/D or best R/C... done the same
> way... fly the plane while watching the best R/C for a given power setting,
> and make that angle.
>
>
>
> Terrence
>
> L235/320
>
> N211AL
>
>
>
> On Mar 30, 2014, at 9:23 AM, Douglas Brunner wrote:
>
>
>
> I am thinking of adding an AOA to my plane.  The two models that I am
> looking at are the Bendix King KLR 10
> (http://www.bendixking.com/Products/Flight-Controls-Indicators/Indicators/KL
> R-10) and one of the Alpha Systems units (http://www.alphasystemsaoa.com/)
>
> My question has to do with the calibration.  Both systems require a
> calibration at 3 points:
>
> 1.      On Ground
>
> 2.      Optimum Alpha Angle
>
> 3.      Cruise
>
>
>
> The "on ground" and "cruise" are self explanatory, however the definition of
> "Optimum Alpha Angle" seems a little "loosey-goosey" to me.  Here are the
> definitions:
>
>
>
> Alpha Systems "Optimum Alpha Angle"
>
> *         Able to hold altitude - as close to 0 VSI as possible, zero sink
>
> *         Full aileron, elevator and rudder control - no buffet or loss of
> control surface stability
>
>
>
> Bendix King "Optimum Alpha Angle"
>
> *         Able to hold altitude, 0 Vertical Speed, zero sink (5 to 10 fpm
> climb OK)
>
> *         Full aileron, elevator and rudder control, not in a buffet, pilot
> to identify the set point by
>
> pitching back slowly to a pitch no longer able to climb but able to hold
> altitude with full
>
> control of the airplane.
>
>
>
>First of all, since this is a system meant to be used in landing (or at
> least that is how I will mostly use it), I intend to calibrate the "Optimum
> Alpha Angle" in landing configuration (gear down, full flaps).  However,
> determining when I have "full aileron, elevator and rudder control" isn't
> all that clear to me.  I am sure that I can tell when I have aileron,
> elevator and rudder control - but the "full" part is less clear.  Does that
> mean a full control deflection?  Not something I am anxious to try that
> close to stall.
>
>
>
> Alternatively, I could just do a stall in landing configuration and set the
> "Optimum Alpha Angle" to 1.3 x stall.
>
>
>
> Advice?
>
>
>
> D. Brunner
>
> N241DB 750 hours
>
>
>