X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 03 Oct 2008 12:03:53 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m23.mx.aol.com ([64.12.137.4] verified) by logan.com (CommuniGate Pro SMTP 5.2.8) with ESMTP id 3197423 for lml@lancaironline.net; Thu, 02 Oct 2008 21:59:51 -0400 Received: from Sky2high@aol.com by imo-m23.mx.aol.com (mail_out_v39.1.) id q.d0f.3b8f2272 (41812) for ; Thu, 2 Oct 2008 21:59:47 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Thu, 2 Oct 2008 21:59:47 EDT Subject: Re: [LML] Small tail vs. large tail X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1222999187" X-Mailer: Unknown sub 34 X-Spam-Flag:NO -------------------------------1222999187 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Jim, et al, Yes, that would seem to be the next check since there are at least a few small tail Lancairs with CG similarities but quite different elevator effectiveness. I propose the following (and I will report on mine the next chance I get). 1. Level the longerons in both the lateral and fore to aft directions (even if you must jack up the aircraft). 2. Clamp the elevator horns to line up with the horizontal stab (neutral position). 3. Place a strip of blue tape 12" inboard and parallel to the cutout in the horzontal stab for the elevator horn (parallel to the aircraft center line). 4. On the tape, mark the middle of the leading edge and the trailing edge. 5. Construct a short (4 to 5 feet) water level tubing and measure the water level difference between the middle of the leading edge and the middle of the trailing edge at a chord line 12" in from the cutout in the horizontal stab for the elevator horn. Call this A. 4. Measure the distance from the leading edge to the trailing edge (the chord line defined in #3). Call this B. 5. Calculate and report the angle represented by the tangent of (A/B). It should be a small negative angle (<1 degree) where the water level showed that the leading edge was lower than the trailing edge. When I installed the horizontal stab, there was a form placed on the centerline in order to set the negative angle of incidence. Lancair recommended that the angle was to be between -0.5 and -1.0 degrees. My AOI was measured during building at -0.9 degrees. At cruise speeds my anecdotal observation out the rear window is that the horn is virtually faired in with the horizontal stab. Maybe a difference in the angle of incidence can help explain the difference in elevator effectiveness. Scott Krueger In a message dated 10/2/2008 8:13:08 P.M. Central Daylight Time, panelmaker@earthlink.net writes: Measure the AOA of the horizontal stabilizer. Compare that to factory book specs. A high angle would serve to reduce elevator effectiveness on the up side. Jim -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Lorn H Olsen Sent: Thursday, October 02, 2008 8:33 AM To: lml@lancaironline.net Subject: [LML] Re: Small tail vs. large tail Bill, Elevator up and down are to book specifications. Some time in the next couple of months, I will try to stop by when you are home and we can do some inspecting. I would like to know why our planes fly so differently (if they really do). Lorn **************Looking for simple solutions to your real-life financial challenges? Check out WalletPop for the latest news and information, tips and calculators. (http://www.walletpop.com/?NCID=emlcntuswall00000001) -------------------------------1222999187 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Jim, et al,

Yes, that would seem to be the next check since there are at least a fe= w=20 small tail Lancairs with CG similarities but quite different elevator=20 effectiveness. I propose the following (and I will report on mine the=20= next=20 chance I get).

1. Level the longerons in both the lateral and fore to aft directi= ons=20 (even if you must jack up the aircraft).

2. Clamp the elevator horns to line up with the horizontal stab (neutra= l=20 position).

3. Place a strip of blue tape 12" inboard and parallel to the cuto= ut=20 in the horzontal stab for the elevator horn (parallel to the aircraft center= =20 line).

4. On the tape, mark the middle of the leading edge and the traili= ng=20 edge.

5. Construct a short (4 to 5 feet) water level tubing and measure the w= ater=20 level difference between the middle of the leading edge and the middle=20= of=20 the trailing edge at a chord line 12" in from the cutout in the horizontal s= tab=20 for the elevator horn. Call this A.

4. Measure the distance from the leading edge to the trailing edge (the= =20 chord line defined in #3). Call this B.

5. Calculate and report the angle represented by the tangent of=20 (A/B). It should be a small negative angle (<1 degree) where the wa= ter=20 level showed that the leading edge was lower than the trailing edge.

When I installed the horizontal stab, there was a form placed on the=20 centerline in order to set the negative angle of incidence. Lanca= ir=20 recommended that the angle was to be between -0.5 and -1.0 degrees. My AOI w= as=20 measured during building at -0.9 degrees. At cruise speeds my anecdota= l=20 observation out the rear window is that the horn is virtually faired in with= the=20 horizontal stab.

Maybe a difference in the angle of incidence can help explain the=20 difference in elevator effectiveness.

Scott Krueger

In a message dated 10/2/2008 8:13:08 P.M. Central Daylight Time,=20 panelmaker@earthlink.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Measure=20 the AOA of the horizontal stabilizer. Compare that to factory book
spec= s. A=20 high angle would serve to reduce elevator effectiveness on the=20 up
side.
Jim

-----Original Message-----
From: Lancair Mail= ing=20 List [mailto:lml@lancaironline.net] On Behalf Of Lorn
H Olsen
Sent:=20 Thursday, October 02, 2008 8:33 AM
To: lml@lancaironline.net
Subject= :=20 [LML] Re: Small tail vs. large tail

Bill,

Elevator up and do= wn=20 are to book specifications. Some time in the next
couple of mont= hs,=20 I will try to stop by when you are home and we can
do some=20 inspecting.

I would like to know why our planes fly so differently=20= (if=20 they really =20
do).

Lorn

Looking for simple solutions to your real-life financ= ial challenges? Check out WalletPop for the latest news and information, tips and ca= lculators. -------------------------------1222999187--