X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 31 Oct 2005 08:06:48 -0500 Message-ID: X-Original-Return-Path: <5zq@cox.net> Received: from eastrmmtao05.cox.net ([68.230.240.34] verified) by logan.com (CommuniGate Pro SMTP 5.0c7) with ESMTP id 800259 for lml@lancaironline.net; Mon, 31 Oct 2005 06:50:07 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.240.34; envelope-from=5zq@cox.net Received: from OFFICE ([68.110.249.147]) by eastrmmtao05.cox.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with SMTP id <20051031114916.UOBF28234.eastrmmtao05.cox.net@OFFICE> for ; Mon, 31 Oct 2005 06:49:16 -0500 X-Original-Message-ID: <027301c5de11$20428d90$6401a8c0@OFFICE> From: "Bill&Sue" <5zq@cox.net> X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Cabin Fire X-Original-Date: Mon, 31 Oct 2005 06:49:18 -0500 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 Hello John, Sorry to hear about Simon. I sure hope that he recovers OK. Yes, there are disadvantages of having a header tank. Simon's situation is the big one. It is, however, exceedingly rare. There are several advantages of the header tank that, in my opinion, outweigh the disadvantages. Here's my list, there are probably more. 1. More fuel capacity. Used wisely, this can be a positive safety factor. 2. Gravity feed, extremely simple. Never worry about cavitation from the fuel pump having to "suck" the fuel up. Vapor lock less likely. 3. Easy to get accurate measurement of quantity. By their nature, wing tanks are shallow and wide. It's difficult to get very accurate quantity measurements in such a "tank". The header is compact and tall, easy to get good capacitance measurements and easy to have a sight gauge which is fairly foolproof. (I have both, accurate to the gallon). 4. A built in reserve. When the wings are dry, you know within a very small margin exactly how much fuel is left. Most of us plan to be on the ground fairly soon after the wings run dry. This gives you a KNOWN reserve of around 10 gallons. You'll know with a high degree of certainty that you can get ALL of that 10 gallons to the engine. You'll never "unport" the fuel pickup as can happen in wing tanks. 5. Keeps the CG forward. (this can be accomplished using other methods also). I would venture to guess that many more injuries and deaths have occurred due to fuel starvation, fuel mismanagement or fuel related mechanical problems than from "fuel in the cockpit" problems. Bill Harrelson 5zq@cox.net N5ZQ 320 1,100 hrs N6ZQ IV 3.019% > Simon's plane had a header tank, and it has got me wondering about the > wisdom of that configuration.