X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 29 Dec 2009 12:53:37 -0500 Message-ID: X-Original-Return-Path: Received: from mail-gx0-f225.google.com ([209.85.217.225] verified) by logan.com (CommuniGate Pro SMTP 5.3.0) with ESMTP id 4050345 for lml@lancaironline.net; Mon, 28 Dec 2009 08:59:56 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.217.225; envelope-from=mwsletten@gmail.com Received: by gxk25 with SMTP id 25so3374148gxk.5 for ; Mon, 28 Dec 2009 05:59:20 -0800 (PST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:references:in-reply-to:subject:date:message-id :mime-version:content-type:x-mailer:content-language:thread-index; b=qxchZzaLfYDh5LdJI7uRMgxJy/hxfoeFLnilec6KROWEkVSrdl8zJRK5WwoVK0rYLJ N1VW3LbPh8mNUS+Kk5V1M/7zwLlrJOg0RluEvQcGKTAMCd01GDXBbU0HbBTcjpYdDYy1 AQlmbJBRALUoLZPIsvBNsSlPzUb2Vv54nL2Js= Received: by 10.101.166.15 with SMTP id t15mr2944223ano.5.1262008760138; Mon, 28 Dec 2009 05:59:20 -0800 (PST) X-Original-Return-Path: Received: from MarkPC (208.65.124.116-dsl.stj.hometel.com [208.65.124.116]) by mx.google.com with ESMTPS id 36sm4674397yxh.31.2009.12.28.05.59.17 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 28 Dec 2009 05:59:18 -0800 (PST) From: "Mark Sletten" X-Original-To: X-Original-Cc: References: In-Reply-To: Subject: RE: [LML] Re: Fuel Planning X-Original-Date: Mon, 28 Dec 2009 07:59:17 -0600 X-Original-Message-ID: <004f01ca87c5$f3467af0$d9d370d0$@com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0050_01CA8793.A8AC0AF0" X-Mailer: Microsoft Office Outlook 12.0 Content-Language: en-us Thread-Index: AcqHM0QnB3TH4BAhRDaxoj01POCCXgAjsyJw This is a multi-part message in MIME format. ------=_NextPart_000_0050_01CA8793.A8AC0AF0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Grayhawk, =20 I didn=E2=80=99t say there is never a good reason for placing fuel in = the fuselage instead of the wing, I only suggested, as I said, that life = is a series of tradeoffs. =20 As to your comment below, I may be misunderstanding your point, but it = seems you are suggesting because the aircraft designer chose a fuel = management system incorporating a header tank there is no additional = stress on the spar by placing fuel weight in the fuselage instead of the = wing. If that=E2=80=99s your position, I disagree. =20 Think of lifting a barbell using a strap on each end. If you place 200 = lbs of weight on each end (400 lbs total), the bar will remain = relatively straight when you lift it. Put that 400 lbs in the middle, = however, and the bar will most definitely flex. =20 Where the engine feeds from isn=E2=80=99t germane, it=E2=80=99s the = location of the weight that matters. Your header tank places some 60 lbs = of weight directly on the center of the spar (I realize its CG is = forward of the spar, but the weight carried by the spar is at the = spar=E2=80=99s center, not towards its ends). While the additional = stress on the spar from that weight may indeed be within design limits, = there can be no question there is additional stress. =20 --Mark =20 From: Sky2high@aol.com [mailto:Sky2high@aol.com]=20 Sent: Sunday, December 27, 2009 2:29 PM To: lml@lancaironline.net Subject: Re: [LML] Re: Fuel Planning =20 Mark, =20 A 300 series Lancair with a header that holds 9-11 gallons will not = affect the spar loading since the original design has the engine fed = from the header. =20 Grayhawk ------=_NextPart_000_0050_01CA8793.A8AC0AF0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Grayhawk,

I didn=E2=80=99t say there is never a good reason for = placing fuel in the fuselage instead of the wing, I only suggested, as I said, that life = is a series of tradeoffs.

As to your comment below, I may be misunderstanding your = point, but it seems you are suggesting because the aircraft designer chose a = fuel management system incorporating a header tank there is no additional = stress on the spar by placing fuel weight in the fuselage instead of the wing. If = that=E2=80=99s your position, I disagree.

Think of lifting a barbell using a strap on each end. If = you place 200 lbs of weight on each end (400 lbs total), the bar will remain = relatively straight when you lift it. Put that 400 lbs in the middle, however, and = =C2=A0the bar will most definitely flex.

Where the engine feeds from isn=E2=80=99t germane, = it=E2=80=99s the location of the weight that matters. Your header tank places some 60 lbs of weight = directly on the center of the spar (I realize its CG is forward of the spar, but = the weight carried by the spar is at the spar=E2=80=99s center, not towards = its ends). While the additional stress on the spar from that weight may indeed be within = design limits, there can be no question there is additional = stress.

--Mark

From:= = Sky2high@aol.com [mailto:Sky2high@aol.com]
Sent: Sunday, December 27, 2009 2:29 PM
To: lml@lancaironline.net
Subject: Re: [LML] Re: Fuel Planning

Mark,

A 300 series Lancair with a header that holds 9-11 gallons = will not affect the spar loading since the original design has the engine fed = from the header.

Grayhawk

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