X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 28 Sep 2008 23:42:37 -0400 Message-ID: X-Original-Return-Path: Received: from [64.12.143.100] (HELO imo-m12.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.2.8) with ESMTP id 3190382 for lml@lancaironline.net; Sun, 28 Sep 2008 14:42:47 -0400 Received: from Sky2high@aol.com by imo-m12.mx.aol.com (mail_out_v39.1.) id q.bea.29181647 (29672) for ; Sun, 28 Sep 2008 14:42:41 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sun, 28 Sep 2008 14:42:41 EDT Subject: Re: [LML] Re: Small tail vs. large tail X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1222627361" X-Mailer: Unknown sub 34 X-Spam-Flag:NO -------------------------------1222627361 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Chris, Thanks for the explanation. I know that there are some 360s using the long engine mount with a small tail. I wonder if that was to correct a rearward CG issue? Perhaps such a person could comment on how that arrangement flies. Scott PS - Is there a really skinny flier out there that was aloft with a heavy prop, no baggage and header fuel only? How was the landing? Has everyone calculated the minimum pilot weight to stay within the forward CG? In a message dated 9/28/2008 12:16:46 P.M. Central Daylight Time, chris_zavatson@yahoo.com writes: <> Scott, The longer engine mounts serves to move the CG forward. The increased surface area of the MKII tail moves the neutral point rearward. The difference between these two defines the static margin. As the static margin goes to zero, the aircraft becomes neutrally stable. This means the MKII tail can handle a more rearward CG than the original for the same degree of stability or conversely, has greater pitch stability for the the same CG location. Two side notes: The long engine mount is actually somewhat destabilizing in yaw and pitch due to the added surface area projected out in front of the CG. The larger tail can also handle a more forward CG since it has more pitch authority at low speeds. The added area in the tail simply opens up the available CG range in both directions. Either tail may be perfectly acceptable as long as each is kept within its individual CG capability. Chris Chris Zavatson N91CZ 360std _www.N91CZ.com_ (http://www.n91cz.com/) **************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) -------------------------------1222627361 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Chris,
 
Thanks for the explanation.  I know that there are some=20 360s using the long engine mount with a small tail.  I wonder if t= hat=20 was to correct a rearward CG issue?  Perhaps such a person could commen= t on=20 how that arrangement flies.
 
Scott
 
PS - Is there a really skinny flier out there that was aloft with a hea= vy=20 prop, no baggage and header fuel only?  How was the landing?  Has=20 everyone calculated the minimum pilot weight to stay within the forward=20 CG?
 
In a message dated 9/28/2008 12:16:46 P.M. Central Daylight Time,=20 chris_zavatson@yahoo.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3D"Times New Roman" color=3D#= 000000=20 size=3D3>
<<The Mark II tail alone exacerbates flight problems at rearwar= d=20 CGs since it adds such a large rearward moment.  Thus the coroll= ary=20 recommendation that the long engine mount be used to move the CG=20 forward.>>
Scott,
The longer engine mounts serves to move the CG forward.  The=20 increased surface area of the MKII tail moves the neutral point=20 rearward.  The difference between these two defines the static=20 margin.  As the static margin goes to zero, the aircraft becomes=20 neutrally stable.  This means the MKII tail can handle a more rearwar= d CG=20 than the original for the same degree of stability or conversely, has grea= ter=20 pitch stability for the the same CG location.   
Two side notes:  The long engine mount is actually somewhat=20 destabilizing in yaw and pitch due to the added surface area projecte= d=20 out in front of the CG.  The larger tail can also handle a more forwa= rd=20 CG since it has more pitch authority at low speeds. 
The added area in the tail simply opens up the available CG rang= e in=20 both directions.  Either tail may be perfectly acceptable as lon= g as=20 each is kept within its individual CG capability.
Chris
 
 
 
Chris Zavatson
N91CZ
360std
 
 

 



Looking for simple solutions to your real-life fi= nancial challenges? Check out WalletPop for the latest news and information, tips an= d calculators.
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