X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 31 Mar 2014 07:36:08 -0400 Message-ID: X-Original-Return-Path: Received: from mta11.charter.net ([216.33.127.80] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTP id 6806804 for lml@lancaironline.net; Sun, 30 Mar 2014 22:41:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=216.33.127.80; envelope-from=troneill@charter.net Received: from imp10 ([10.20.200.15]) by mta11.charter.net (InterMail vM.8.01.05.09 201-2260-151-124-20120717) with ESMTP id <20140331024039.ZJVE6169.mta11.charter.net@imp10> for ; Sun, 30 Mar 2014 22:40:39 -0400 Received: from [192.168.169.2] ([75.132.161.69]) by imp10 with smtp.charter.net id k2ge1n00M1W8Pdn052ge3z; Sun, 30 Mar 2014 22:40:39 -0400 X-Authority-Analysis: v=2.0 cv=Q7eKePKa c=1 sm=1 a=dksOS2KhiOYOTGJMmz5HMQ==:17 a=i-_0iLLR02oA:10 a=yUnIBFQkZM0A:10 a=hOpmn2quAAAA:8 a=3oc9M9_CAAAA:8 a=5Up8faWwAAAA:8 a=Ia-xEzejAAAA:8 a=uPYnuhDeAAAA:8 a=agrPUkRYAAAA:8 a=c9vWVNho87JLwjre45sA:9 a=QEXdDO2ut3YA:10 a=U8Ie8EnqySEA:10 a=v6MMM96S_sUA:10 a=EzXvWhQp4_cA:10 a=rzzP_kbwrucA:10 a=gTK_HDuECHJaW_Fe:21 a=LwyLRFbAutot_dI5:21 a=KAl-cX9SZSawlml7qOYA:9 a=_W_S_7VecoQA:10 a=dksOS2KhiOYOTGJMmz5HMQ==:117 X-Auth-id: dHJvbmVpbGxAY2hhcnRlci5uZXQ= Subject: Re: [LML] Re: FW: Adding an AOA References: From: Troneill Content-Type: multipart/alternative; boundary=Apple-Mail-CE810442-EDCE-4079-A448-E3311E8518DD X-Mailer: iPad Mail (10B329) In-Reply-To: X-Original-Message-Id: <93DD3E5D-D898-45C0-8326-D7CE3B101E70@charter.net> X-Original-Date: Sun, 30 Mar 2014 21:40:38 -0500 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-CE810442-EDCE-4079-A448-E3311E8518DD Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Doug. ...What Scott said. Terrence Sent from my iPad On Mar 30, 2014, at 4:23 PM, Sky2high@aol.com wrote: > Doug, > =20 > Sophisticated AOA indications take into account atmospheric conditions and= G-loading along with IAS. In theory, there are straight line functions bet= ween interesting points on the relevant AOA such as best glide, stall, etc. = The old fashioned 1.3 Vso is dangerous in aircraft with high performance wi= ngs - because the stall speed does vary with G-load and, uh, the air. In La= ncairs, 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 c= alibrate the function (uh. the parallel straight line moves because of the o= ther parameters. Some system calibrations do not require the stall point as= one measure (see Advanced Systems). Some require the zero G (zero lift) po= int as one. Be careful. > =20 > Simpler system rely merely on AOA to the relative wind. This is useful be= cause exceeding the stall AOA results in a stall. The sophisticated systems= yield other useful information (best glide, etc). > =20 > Do further study to educate yourself about AOA. > =20 > Scott Krueger > =20 > =20 > In a message dated 3/30/2014 2:35:00 P.M. Central Daylight Time, douglasbr= unner@earthlink.net writes: > Terrence, >=20 > =20 >=20 > There is no =E2=80=9Cangle=E2=80=9D to mark. Both instruments use an arra= y of colored lights - in both, the top colored light is a red arrow pointin= g down =E2=80=93 presumably this is to indicate a stall. >=20 > =20 >=20 > 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) >=20 > =20 >=20 > My question was whether to set it to 1.3 Vso or to do the maneuver describ= ed in the setup. >=20 > =20 >=20 > D. Brunner >=20 > =20 >=20 > From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Ter= rence O'Neill > Sent: Sunday, March 30, 2014 2:18 PM > To: lml@lancaironline.net > Subject: [LML] Re: FW: Adding an AOA >=20 > =20 >=20 > D., >=20 > =20 >=20 > IMHO the prime purpose of an AOA is: >=20 > =20 >=20 > To make the wing's STALL ANGLE visible to the pilot. You do that by flyi= ng the plane and stalling it as you watch the AOA... then mark that angle. >=20 > 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. >=20 > =20 >=20 > Terrence >=20 > L235/320 >=20 > N211AL >=20 > =20 >=20 > On Mar 30, 2014, at 9:23 AM, Douglas Brunner wrote: >=20 >=20 >=20 >=20 > I am thinking of adding an AOA to my plane. The two models that I am loo= king at are the Bendix King KLR 10 (http://www.bendixking.com/Products/Fligh= t-Controls-Indicators/Indicators/KLR-10) and one of the Alpha Systems units (= http://www.alphasystemsaoa.com/) >=20 > My question has to do with the calibration. Both systems require a calibr= ation at 3 points: >=20 > 1. On Ground >=20 > 2. Optimum Alpha Angle >=20 > 3. Cruise >=20 > =20 >=20 > The =E2=80=9Con ground=E2=80=9D and =E2=80=9Ccruise=E2=80=9D are self expl= anatory, however the definition of =E2=80=9COptimum Alpha Angle=E2=80=9D see= ms a little =E2=80=9Cloosey-goosey=E2=80=9D to me. Here are the definitions= : >=20 > =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 control surface stability >=20 > =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 climb OK) >=20 > =C2=B7 Full aileron, elevator and rudder control, not in a buffet,= pilot to identify the set point by >=20 > pitching back slowly to a pitch no longer able to climb but able to hold a= ltitude with full >=20 > control of the airplane. >=20 > =20 >=20 > First of all, since this is a system meant to be used in landing (or at le= ast that is how I will mostly use it), I intend to calibrate the =E2=80=9COp= timum Alpha Angle=E2=80=9D in landing configuration (gear down, full flaps).= However, determining when I have =E2=80=9Cfull aileron, elevator and rudde= r control=E2=80=9D isn=E2=80=99t all that clear to me. I am sure that I can= tell when I have aileron, elevator and rudder control =E2=80=93 but the =E2= =80=9Cfull=E2=80=9D part is less clear. Does that mean a full control defle= ction? Not something I am anxious to try that close to stall. >=20 > =20 >=20 > Alternatively, I could just do a stall in landing configuration and set th= e =E2=80=9COptimum Alpha Angle=E2=80=9D to 1.3 x stall. >=20 > =20 >=20 > Advice? >=20 > =20 >=20 > D. Brunner >=20 > N241DB 750 hours >=20 > =20 --Apple-Mail-CE810442-EDCE-4079-A448-E3311E8518DD Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Doug.

...What= Scott said.

Terrence

Sent from my iPad

On Mar 30, 2014, at 4:23 PM, S= ky2high@aol.com wrote:

Doug,
 
Sophisticated AOA indications take into account atmospheric conditions a= nd=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=20 performance wings - because the stall speed does vary with G-load and, uh, t= he=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 l= ine=20 to calibrate the function (uh. the parallel straight line moves because= of=20 the other parameters.  Some system calibrations do not require the stal= l=20 point as one measure (see Advanced Systems).  Some require the zer= o 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 array= 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 V= so)=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 i= n=20 the setup.

 

D.=20 Brunner

 

From: Lancair= Mailing=20 List [mailto:lml@lancaironline.ne= t] On Behalf Of Terrence=20 O'Neill
Sent: Sunday, March 30, 2014 2:18 PM
To:=20 lml@lancaironline.net
S= ubject: [LML] Re: FW: Adding an=20 AOA

 

D.,

 

IMHO the prime purpose of an AOA is:

=

 

To make the w= ing's=20 STALL  ANGLE visible to the pilot.  You do that by flying the pl= ane=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 be= st=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 KL= R 10=20 (http://www.bendixking.com/Products/Flight-C= ontrols-Indicators/Indicators/KLR-10)=20 and one of the Alpha Systems units (http://www.alphasystemsaoa.c= om/)

My q= uestion has to do with the=20 calibration.  Both systems require a calibration at 3 points:<= span style=3D"FONT-SIZE: 11pt; FONT-FAMILY: "Calibri","sans-s= erif"">

1.      On Ground

<= /div>

2.      Optimum Alpha Angle

3.      Cruise

 

The =E2=80=9Con=20 ground=E2=80=9D and =E2=80=9Ccruise=E2=80=9D are self explanatory, however= 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  &nbs= p;      = Able to hold altitude =E2=80=93 as close=20 to 0 VSI as possible, zero sink

<= /div>

=C2=B7  &nbs= p;      = 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<= /span>

=C2=B7  &nbs= p;      = Able to hold altitude, 0 Vertical=20 Speed, zero sink (5 to 10 fpm climb OK)

=C2=B7  &nbs= p;      = 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 w= ith=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 i= s=20 how I will mostly use it), I intend to calibrate the =E2=80=9COptimum Alph= a Angle=E2=80=9D in=20 landing configuration (gear down, full flaps).  However, determining w= hen=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 rudd= er=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?

=

&nb= sp;

D. B= runner

N24= 1DB 750 hours

 

= --Apple-Mail-CE810442-EDCE-4079-A448-E3311E8518DD--