X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from omr-m05.mx.aol.com ([64.12.143.79] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6806690 for lml@lancaironline.net; Sun, 30 Mar 2014 17:24:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.143.79; envelope-from=Sky2high@aol.com Received: from mtaomg-mba01.mx.aol.com (mtaomg-mba01.mx.aol.com [172.26.133.111]) by omr-m05.mx.aol.com (Outbound Mail Relay) with ESMTP id F25307020B5E7 for ; Sun, 30 Mar 2014 17:23:52 -0400 (EDT) Received: from core-mla005b.r1000.mail.aol.com (core-mla005.r1000.mail.aol.com [172.29.186.83]) by mtaomg-mba01.mx.aol.com (OMAG/Core Interface) with ESMTP id B169638000082 for ; Sun, 30 Mar 2014 17:23:52 -0400 (EDT) From: Sky2high@aol.com Full-name: Sky2high Message-ID: <510c.2b1ccbd4.4069e568@aol.com> Date: Sun, 30 Mar 2014 17:23:52 -0400 (EDT) Subject: Re: [LML] Re: FW: Adding an AOA To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_510c.2b1ccbd4.4069e568_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [24.14.166.87] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1396214632; bh=eX7S+i5AO6eXGdbNcV6d9M8mhycUZYxmnR0PodH/rak=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=pPqKOgpE5WPmxpr8s7bAcs9aazb4u/O1+Y6wZ2ufNYKYGxUJpkIN/dLGvq5Uo8Da9 bMv7QLQ4LqbwuBA20yFTCcegyP+Baa+uijjoPTwrvCfFEm3DqJ5Uo60er8dCj3K/YN T09nO0NSr3e24mDuZAJjmq+hG086x97SgeIV6S6I= x-aol-sid: 3039ac1a856f53388b681ea9 --part1_510c.2b1ccbd4.4069e568_boundary Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en Doug, =20 Sophisticated AOA indications take into account atmospheric conditions and = =20 G-loading along with IAS. In theory, there are straight line functions =20 between interesting points on the relevant AOA such as best glide, stall, = =20 etc. The old fashioned 1.3 Vso is dangerous in aircraft with high perform= ance=20 wings - because the stall speed does vary with G-load and, uh, the air. = =20 In Lancairs, 1.3 Vso does not provide proper margins in all cases. =20 The sophisticated AOA systems need only 2 points on the straight line to= =20 calibrate the function (uh. the parallel straight line moves because of th= e=20 other parameters. Some system calibrations do not require the stall point= =20 as one measure (see Advanced Systems). Some require the zero G (zero lift= )=20 point as one. Be careful. =20 Simpler system rely merely on AOA to the relative wind. This is useful=20 because exceeding the stall AOA results in a stall. The sophisticated=20 systems yield other useful information (best glide, etc). =20 Do further study to educate yourself about AOA. =20 Scott Krueger =20 =20 =20 In a message dated 3/30/2014 2:35:00 P.M. Central Daylight Time, =20 douglasbrunner@earthlink.net writes: =20 Terrence,=20 There is no =E2=80=9Cangle=E2=80=9D to mark. Both instruments use an arra= y of colored=20 lights - in both, the top colored light is a red arrow pointing down =E2= =80=93 =20 presumably this is to indicate a stall.=20 The way that both are made to be used is to define a safe speed (roughly= =20 1.3 Vso) that can be used during landing (and other maneuvers)=20 My question was whether to set it to 1.3 Vso or to do the maneuver=20 described in the setup.=20 D. Brunner=20 =20 =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of=20 Terrence O'Neill Sent: Sunday, March 30, 2014 2:18 PM To: lml@lancaironline.net Subject: [LML] Re: FW: Adding an AOA D.,=20 =20 =20 IMHO the prime purpose of an AOA is:=20 =20 To make the wing's STALL ANGLE visible to the pilot. You do that by=20 flying the plane and stalling it as you watch the AOA... then mark that a= ngle. =20 The next most useful AOA info is the best L/D or best R/C... done the same= =20 way... fly the plane while watching the best R/C for a given power=20 setting, and make that angle. =20 =20 Terrence =20 L235/320 =20 N211AL =20 =20 =20 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=20 looking at are the Bendix King KLR 10 =20 (http://www.bendixking.com/Products/Flight-Controls-Indicators/Indicators/K= LR-10) and one of the Alpha Systems units=20 (http://www.alphasystemsaoa.com/)=20 My question has to do with the calibration. Both systems require a=20 calibration at 3 points:=20 =20 1. On Ground =20 2. Optimum Alpha Angle =20 3. Cruise =20 =20 The =E2=80=9Con ground=E2=80=9D and =E2=80=9Ccruise=E2=80=9D are self expl= anatory, however the=20 definition of =E2=80=9COptimum Alpha Angle=E2=80=9D seems a little =E2=80= =9Cloosey-goosey=E2=80=9D to me. Here=20 are the definitions: =20 =20 Alpha Systems =E2=80=9COptimum Alpha Angle=E2=80=9D =20 =C2=B7 Able to hold altitude =E2=80=93 as close to 0 VSI as possib= le, zero sink =20 =C2=B7 Full aileron, elevator and rudder control =E2=80=93 no buff= et or loss of=20 control surface stability =20 =20 Bendix King =E2=80=9COptimum Alpha Angle=E2=80=9D =20 =C2=B7 Able to hold altitude, 0 Vertical Speed, zero sink (5 to 10= fpm=20 climb OK) =20 =C2=B7 Full aileron, elevator and rudder control, not in a buffet,= =20 pilot to identify the set point by =20 pitching back slowly to a pitch no longer able to climb but able to hold= =20 altitude with full =20 control of the airplane. =20 =20 First of all, since this is a system meant to be used in landing (or at=20 least that is how I will mostly use it), I intend to calibrate the =E2=80= =9COptimum=20 Alpha Angle=E2=80=9D in landing configuration (gear down, full flaps). Ho= wever,=20 determining when I have =E2=80=9Cfull aileron, elevator and rudder control= =E2=80=9D isn=E2=80=99t all=20 that clear to me. I am sure that I can tell when I have aileron, elevator= =20 and rudder control =E2=80=93 but the =E2=80=9Cfull=E2=80=9D part is less c= lear. Does that mean a=20 full control deflection? Not something I am anxious to try that close to = =20 stall. =20 =20 Alternatively, I could just do a stall in landing configuration and set=20 the =E2=80=9COptimum Alpha Angle=E2=80=9D to 1.3 x stall. =20 =20 Advice? D. Brunner=20 N241DB 750 hours --part1_510c.2b1ccbd4.4069e568_boundary Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
Doug,
 
Sophisticated AOA indications take into account atmospheric conditions= and=20 G-loading along with IAS.  In theory, there are straight line function= s=20 between interesting points on the relevant AOA such as best glide, stall,= =20 etc.  The old fashioned 1.3 Vso is dangerous in aircraft with high=20 performance wings - because the stall speed does vary with G-load and, uh, = the=20 air.  In Lancairs, 1.3 Vso does not provide proper margins in all= =20 cases.
 
The sophisticated AOA systems need only 2 points on the straight = line=20 to calibrate the function (uh. the parallel straight line moves becaus= e of=20 the other parameters.  Some system calibrations do not require the sta= ll=20 point as one measure (see Advanced Systems).  Some require the ze= ro G=20 (zero lift) point as one.  Be careful.
 
Simpler system rely merely on AOA to the relative wind.  This is= =20 useful because exceeding the stall AOA results in a stall.  The= =20 sophisticated systems yield other useful information (best glide, etc).
 
Do further study to educate yourself about AOA.
 
Scott Krueger
 
 
In a message dated 3/30/2014 2:35:00 P.M. Central Daylight Time,=20 douglasbrunner@earthlink.net writes:
=

Terrence,

 

There=20 is no =E2=80=9Cangle=E2=80=9D to mark.  Both instruments use an arra= y of colored lights=20 -  in both, the top colored light is a red arrow pointing down =E2= =80=93=20 presumably this is to indicate a stall.

 

The=20 way that both are made to be used is to define a safe speed (roughly 1.3 = Vso)=20 that can be used during landing (and other maneuvers)

 

My=20 question was whether to set it to 1.3 Vso or to do the maneuver described= in=20 the setup.

 

D.=20 Brunner

 

From: Lancair Ma= iling=20 List [mailto:lml@lancaironline.net] On Behalf Of Terrence=20 O'Neill
Sent: Sunday, March 30, 2014 2:18 PM
To:=20 lml@lancaironline.net
Subject: [LML] Re: FW: Adding an=20 AOA

 

D.,

 

IMHO the prime purpose of an AOA is:

 

To make the wi= ng's=20 STALL  ANGLE visible to the pilot.  You do that by flying the p= lane=20 and stalling it as you watch the AOA... then mark that=20 angle.

The next most useful AOA info is the best L/D or bes= t=20 R/C... done the same way... fly the plane while watching the best R/C for= a=20 given power setting, and make that angle.

 

Terrence

L235/320

N211AL

 

On Mar 30, 2014, at 9:23 AM, Douglas Brunner=20 wrote:



=  I am thinking of adding an = AOA to=20 my plane.  The two models that I am looking at are the Bendix King K= LR 10=20 (http://www.bendixking.com/Products/Flight-Controls-Indicato= rs/Indicators/KLR-10)=20 and one of the Alpha Systems units (http://www.alphasystemsaoa.com/<= /A>)

= My question has to do with = the=20 calibration.  Both systems require a calibration at 3 points:=

1.      On Ground

2.      Optimum Alpha Angle<= SPAN=20 style=3D'FONT-SIZE: 11pt; FONT-FAMILY: "Calibri","sans-serif"'>

3.      Cruise

 

= The =E2=80=9Con=20 ground=E2=80=9D and =E2=80=9Ccruise=E2=80=9D are self explanatory, howeve= r the definition of =E2=80=9COptimum=20 Alpha Angle=E2=80=9D seems a little =E2=80=9Cloosey-goosey=E2=80=9D to me= .  Here are the=20 definitions:

 

= Alpha=20 Systems =E2=80=9COptimum Alpha Angle=E2=80=9D

=C2=B7        =  Able to hold altitude =E2= =80=93 as close=20 to 0 VSI as possible, zero sink

=C2=B7        =  Full aileron, elevator and = rudder=20 control =E2=80=93 no buffet or loss of control surface stability

 

= Bendix=20 King =E2=80=9COptimum Alpha Angle=E2=80=9D

=C2=B7        =  Able to hold altitude, 0 Ve= rtical=20 Speed, zero sink (5 to 10 fpm climb OK)

=C2=B7        =  Full aileron, elevator and = rudder=20 control, not in a buffet, pilot to identify the set point by

= pitching=20 back slowly to a pitch no longer able to climb but able to hold altitude = with=20 full

= control=20 of the airplane.

 

= First of=20 all, since this is a system meant to be used in landing (or at least that= is=20 how I will mostly use it), I intend to calibrate the =E2=80=9COptimum Alp= ha Angle=E2=80=9D in=20 landing configuration (gear down, full flaps).  However, determining= when=20 I have =E2=80=9Cfull aileron, elevator and rudder control=E2=80=9D isn=E2= =80=99t all that clear to=20 me.  I am sure that I can tell when I have aileron, elevator and rud= der=20 control =E2=80=93 but the =E2=80=9Cfull=E2=80=9D part is less clear. = ; Does that mean a full=20 control deflection?  Not something I am anxious to try that close to= =20 stall.

 

Alternatively, I could just= do a=20 stall in landing configuration and set the =E2=80=9COptimum Alpha Angle= =E2=80=9D to 1.3 x=20 stall.

 

Advice?

=  

= D. Brunner

= N241DB 750 hours

 

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