X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 07 Jun 2007 00:43:16 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-curtail.atl.sa.earthlink.net ([209.86.89.64] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2088519 for lml@lancaironline.net; Wed, 06 Jun 2007 23:57:25 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.64; envelope-from=rtitsworth@mindspring.com DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=mindspring.com; b=dkFAPQXhqWjKbjbs7Bn8LpmPDVqWBWvWXAj4lvJEC0mHy6yyQC2cJUgVa4uFJ+5/; h=Received:From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Mailer:X-MimeOLE:thread-index:In-Reply-To:X-ELNK-Trace:X-Originating-IP; Received: from [69.3.252.251] (helo=RDTVAIO) by elasmtp-curtail.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1Hw97B-0002PL-1I for lml@lancaironline.net; Wed, 06 Jun 2007 23:56:49 -0400 From: "rtitsworth" X-Original-To: "'Lancair Mailing List'" Subject: RE: [LML] Re: Boost switch X-Original-Date: Wed, 6 Jun 2007 23:56:32 -0400 X-Original-Message-ID: <012e01c7a8b7$d673e6f0$84affea9@RDTVAIO> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 thread-index: Aceoe5NaDyuolIslR9qg6pxfrlqdXQAOCABQ In-Reply-To: X-ELNK-Trace: b17f11247b2ac8f0a79dc4b33984cbaa0a9da525759e2654694fc454abf7be888e383e064b6d258a93caf27dac41a8fd350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 69.3.252.251 Paul (etal), My (limited) understanding is that if the mechanical engine fuel pump fails, then you will (may) need the high boost to keep the engine running. Thus, "momentary" high boost may not be a good choice for that scenario. I'm planning on having a small momentary button near the key (or throttle) to be used to assist with starting and a separate "emergency" high boost on-off switch which is located out of the way (upper left side) for any potential/unlikely mechanical fuel pump failure event (probably with a switch guard). The separate Low boost on-off switch which may be used during take-off and during fuel tank changes (per certified Columbia POH) will be located centrally (near the throttle quadrant). Question: In a two separate low/high boost switch scenario, what happens if both switches are inadvertently switched on at the same time??? Do we need some sort of additional protection for this - such as using a DPDT for the high boost and wiring the low boost through it (backwards) so low boost is automatically off if/when the high boost is on??? Rick -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Paul Bricker At the recommendation of Ron Galbraith I'm currently changing out my 3 position OFF/Low/High fuel pump switch for OFF/Low with a separate momentary High push button for priming/start.