X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3877756 for flyrotary@lancaironline.net; Wed, 07 Oct 2009 10:22:47 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=alventures@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao104.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20091007142212.BGMC14181.fed1rmmtao104.cox.net@fed1rmimpo03.cox.net> for ; Wed, 7 Oct 2009 10:22:12 -0400 Received: from BigAl ([72.192.133.78]) by fed1rmimpo03.cox.net with bizsmtp id pqNB1c0021hf1Cg04qNBut; Wed, 07 Oct 2009 10:22:11 -0400 X-VR-Score: 0.00 X-Authority-Analysis: v=1.0 c=1 a=O_fsNjRYJx37--zOYykA:9 a=2TRQ7dWHxL8-cZHfC0dvI8flPMQA:4 a=CbkMQQMLx6RraGVuXFMA:9 a=1bnLUFyz3YhIFsW8Wi0A:7 a=MwGiAaA-1AFi0SN6y_Ut9ZHrbTkA:4 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Fuel System Date: Wed, 7 Oct 2009 07:22:29 -0800 Message-ID: <6D570FB6B23C4B43B5AFC9752C5D0290@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0028_01CA471E.ED6CC540" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6838 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-Reply-To: Thread-Index: AcpHShZBeDJd/I3GT26yboHY/7vB1gAFwteA Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0028_01CA471E.ED6CC540 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable As far as the return: That was for overflow should the transfer pump remain on after filling = the header tank.=20 If this happened and there was a vent then it would pump fuel overboard. = If there was no vent then it would pressurize the header tank to Facet = pressure minus any pressure reduction caused by the sum of the outgoing and returning fuel from the main rail. I thought even a few psi would be dangerous for the tank. Steve Izett Of course - I was thinking in terms of gravity feed from mains to sump = as in my case. Are you suggesting then that if the header has no air leaks then the = main pump suction could be used to draw fuel from main wing tank up into = header and delete the transfer pump? Under most conditions it would, but I wouldn't take that approach. As = Ed says, any air leak would be an issue, and on a hot day at altitude with mogas - don't tempt vapor lock. Al ------=_NextPart_000_0028_01CA471E.ED6CC540 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Re: Fuel System

As far as the return:
That was for overflow should the transfer pump remain on after filling = the header tank.
If this happened and there was a vent then it would pump fuel overboard. = If there was no vent then it would pressurize the header tank to Facet = pressure minus any pressure reduction caused by the sum of the outgoing  and returning fuel from the main rail. I thought even a few psi would be = dangerous for the tank.
Steve Izett

Of course – I was thinking in = terms of gravity feed from mains to sump as in my case.

Are you suggesting then that if the header has no air leaks then the main = pump suction could be used to draw fuel from main wing tank up into header = and delete the transfer pump?

Under most conditions it would, but I = wouldn’t take that approach.  As Ed says, any air leak would be an issue, = and on a hot day at altitude with mogas – don’t tempt vapor = lock.

Al

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