X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 31 Mar 2014 07:35:24 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-banded.atl.sa.earthlink.net ([209.86.89.70] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTP id 6806714 for lml@lancaironline.net; Sun, 30 Mar 2014 18:20:23 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.70; envelope-from=douglasbrunner@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=RzdS7qqM5ZA0vui5+wRFXyRMitQmQILfpf0AJaBnyO+Z5+SyPZc6HcuGYAugJ1/f; h=Received:From:To:References:In-Reply-To:Subject:Date:Message-ID:MIME-Version:Content-Type:X-Mailer:Thread-Index:Content-Language:X-ELNK-Trace:X-Originating-IP; Received: from [67.8.30.30] (helo=DougsVAIO) by elasmtp-banded.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1WUO4z-00017B-Et for lml@lancaironline.net; Sun, 30 Mar 2014 18:19:49 -0400 From: "Douglas Brunner" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Re: FW: Adding an AOA X-Original-Date: Sun, 30 Mar 2014 18:19:48 -0400 X-Original-Message-ID: <004c01cf4c66$2a2ea970$7e8bfc50$@net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004D_01CF4C44.A31D0970" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Ac9MXvSEHhuu2QKpQ6+sMs1/0pGHlgABiwPQ Content-Language: en-us X-ELNK-Trace: ad85a799c4f5de37c2eb1477c196d22294f5150ab1c16ac0b4de374c5ae8ff79ce208d59bebc7d747bcc74abc3f7e82c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 67.8.30.30 This is a multi-part message in MIME format. ------=_NextPart_000_004D_01CF4C44.A31D0970 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Scott, =20 I understand that the AOA takes into account atmospheric conditions, g = loading, weight of the plane, etc. That is why I am interested in it = rather than just using airspeed. My problem is that one of the points = to be used for calibration is, in my opinion, a subjective point. =20 You say that 1.3 Vso is dangerous with a high performance wing. What = number is a better one? =20 I was taught to fly final at 110 and to slow to 90 over the numbers = =E2=80=93 which is what I normally do. Recently, I flew with a retired = fighter pilot who told me I was too fast on final. I told him that it = was better to be too fast and land long than be too slow and stall. But = it started me thinking about a more optimal speed given how much runway = I frequently use. =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Sky2high@aol.com Sent: Sunday, March 30, 2014 5:24 PM To: lml@lancaironline.net Subject: [LML] Re: FW: Adding an AOA =20 Doug, =20 Sophisticated AOA indications take into account atmospheric conditions = and G-loading along with IAS. In theory, there are straight line = functions between 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 wings - because the stall speed does vary with = G-load and, uh, the air. 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 = calibrate the function (uh. the parallel straight line moves because of = the other parameters. Some system calibrations do not require the stall = point as one measure (see Advanced Systems). Some require the zero G = (zero lift) point as one. Be careful. =20 Simpler system rely merely on AOA to the relative wind. This is useful = because 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, = douglasbrunner@earthlink.net writes: Terrence, =20 There is no =E2=80=9Cangle=E2=80=9D to mark. Both instruments use an = array of colored lights - in both, the top colored light is a red arrow = pointing down =E2=80=93 presumably this is to indicate a stall. =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 My question was whether to set it to 1.3 Vso or to do the maneuver = described in the setup. =20 D. Brunner =20 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 =20 D., =20 IMHO the prime purpose of an AOA is: =20 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. =20 Terrence L235/320 N211AL =20 On Mar 30, 2014, at 9:23 AM, Douglas Brunner wrote: =20 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= /KLR-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 =20 The =E2=80=9Con ground=E2=80=9D and =E2=80=9Ccruise=E2=80=9D are self = explanatory, however the definition of =E2=80=9COptimum Alpha = Angle=E2=80=9D seems a little =E2=80=9Cloosey-goosey=E2=80=9D to me. = Here are the definitions: =20 Alpha Systems =E2=80=9COptimum Alpha Angle=E2=80=9D =C2=B7 Able to hold altitude =E2=80=93 as close to 0 VSI as = possible, zero sink =C2=B7 Full aileron, elevator and rudder control =E2=80=93 no = buffet or loss of control surface stability =20 Bendix King =E2=80=9COptimum Alpha Angle=E2=80=9D =C2=B7 Able to hold altitude, 0 Vertical Speed, zero sink (5 to = 10 fpm climb OK) =C2=B7 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. =20 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 = =E2=80=9COptimum Alpha Angle=E2=80=9D in landing configuration (gear = down, full flaps). However, determining when I have =E2=80=9Cfull = aileron, elevator and rudder 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 deflection? Not something I am = anxious to try that close to stall. =20 Alternatively, I could just do a stall in landing configuration and set = the =E2=80=9COptimum Alpha Angle=E2=80=9D to 1.3 x stall. =20 Advice? =20 D. Brunner N241DB 750 hours =20 ------=_NextPart_000_004D_01CF4C44.A31D0970 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Scott,

 

I understand that the AOA takes into account atmospheric conditions, = g loading, weight of the plane, etc.=C2=A0 That is why I am interested = in it rather than just using airspeed.=C2=A0 My problem is that one of = the points to be used for calibration is, in my opinion, a subjective = point.

 

You say that 1.3 Vso is dangerous with a high performance wing.=C2=A0 = What number is a better one?

 

I was taught to fly final at 110 and to slow to 90 over the numbers = =E2=80=93 which is what I normally do.=C2=A0 Recently, I flew with a = retired fighter pilot who told me I was too fast on final.=C2=A0 I told = him that it was better to be too fast and land long than be too slow and = stall.=C2=A0 But it started me thinking about a more optimal speed given = how much runway I frequently use.

 

From:= = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Sky2high@aol.com
Sent: Sunday, March 30, 2014 5:24 = PM
To: lml@lancaironline.net
Subject: [LML] Re: FW: = Adding an AOA

 

D= oug,

&= nbsp;

S= ophisticated AOA indications take into account atmospheric conditions = and G-loading along with IAS.  In theory, there are straight line = functions between 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 wings - because the stall speed does vary = with G-load and, uh, the air.  In Lancairs, 1.3 Vso does not = provide proper margins in all cases.

&= nbsp;

T= he sophisticated AOA systems need only 2 points on the straight = line to calibrate the function (uh. the parallel straight line = moves because of the other parameters.  Some system calibrations do = not require the stall point as one measure (see Advanced = Systems).  Some require the zero G (zero lift) point as one.  = Be careful.

&= nbsp;

S= impler system rely merely on AOA to the relative wind.  This is = useful because exceeding the stall AOA results in a stall.  = The sophisticated systems yield other useful information (best glide, = etc).

&= nbsp;

D= o further study to educate yourself about = AOA.

&= nbsp;

S= cott Krueger

&= nbsp;

&= nbsp;

I= n a message dated 3/30/2014 2:35:00 P.M. Central Daylight Time, douglasbrunner@earthlink.net= writes:

Terrence,

 

There is no =E2=80=9Cangle=E2=80=9D to mark.  Both instruments = use an array of colored lights -  in both, the top colored light is = a red arrow pointing down =E2=80=93 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
Sub= ject: [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-Indic= ators/Indicators/KLR-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 =E2=80=9Con = ground=E2=80=9D and =E2=80=9Ccruise=E2=80=9D are self explanatory, = however the definition of =E2=80=9COptimum Alpha Angle=E2=80=9D seems a = little =E2=80=9Cloosey-goosey=E2=80=9D to me.  Here are the = definitions:

 

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

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

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

 

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

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

=C2=B7      = ;   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 =E2=80=9COptimum = Alpha Angle=E2=80=9D in landing configuration (gear down, full = flaps).  However, determining when I have =E2=80=9Cfull aileron, = elevator and rudder 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 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 = =E2=80=9COptimum Alpha Angle=E2=80=9D to 1.3 x stall.

 

Advice?

 

D. = Brunner

N241DB = 750 hours

 

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