X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 20 Dec 2009 19:37:21 -0500 Message-ID: X-Original-Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.3c4) with ESMTP id 4032455 for lml@lancaironline.net; Sun, 20 Dec 2009 16:56:52 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=super_chipmunk@roadrunner.com X-Original-Return-Path: X-Authority-Analysis: v=1.0 c=1 a=vFRZVaHBOfg7qX26C7UA:9 a=-rWXRnBMQr2t-MdAp-_9xMUwz3kA:4 a=be69OBZivvGZTByZ:21 a=L02NKOmqXG386ZZh:21 a=807Y1gU-Gtu1qRwiQ_UA:9 a=7HaIW2aRUJikzm6zMbUA:7 a=DcvQ2zAmm54iGUXlrMWzyqi6GTwA:4 X-Cloudmark-Score: 0 X-Originating-IP: 74.75.176.139 Received: from [74.75.176.139] ([74.75.176.139:58474] helo=Laptop) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id BE/9F-01567-08D9E2B4; Sun, 20 Dec 2009 21:56:16 +0000 X-Original-Message-ID: <8E5D595B00CB413CB9A5B6310FB836B6@Laptop> From: "Bill Wade" X-Original-To: "Lancair Mailing List" References: In-Reply-To: Subject: Re: [LML] Re: Firewall X-Original-Date: Sun, 20 Dec 2009 16:56:19 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_04F0_01CA8195.5A517B00" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18005 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18005 This is a multi-part message in MIME format. ------=_NextPart_000_04F0_01CA8195.5A517B00 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable It occurs to me that the thermal fuses could be mounted against the = firewall, under the firewall blanket. They're not much larger than = resistors and distributing them around the firewall would give an = indirect engine fire indication and would also guard against the = situation that Brad Simmons discovered. 144 dC fuses are available at = Radio Shack, and would fail at 291 dF. This is slightly above the = prepreg cure temp of 270 dF that Lancair mentions for the Legacy. They = imply the other models are cured under the same conditions but the = factory should be able to confirm that. Lancair's website also states that the IV materials strength and = stiffness was tested at 170 dF. Perhaps a fuse designed for a = temperature between 170 and 270 dF would give warning when there was = still an adequate reserve of strength while reducing the possibility of = a false alarm. In addition I have read that titanium is difficult to machine because = it doesn't transfer heat easily. For example, the heat from drilling a = hole tends to build up rather than dissipate into the surrounding metal = so the use of coolant is required. Low heat transfer is what we're = looking for in this application- has anyone considered using it as a = shield for fiberfrax or the blanket? -Bill Wade We are in the process of repairing a IVP engine fire that was centered = on the passenger aft side of the engine compartment, and the firewall = blanket just barely did it's job. There is signifigant scorching around = the perimeter, through every penetration, and around the cowl attach = flange. Brad Simmons Airframes Inc. Milan,=20 ------=_NextPart_000_04F0_01CA8195.5A517B00 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
  It occurs to me that the thermal = fuses could=20 be mounted against the firewall, under the firewall blanket. They're not = much=20 larger than resistors and distributing them around the = firewall would=20 give an indirect engine fire indication and would also guard against the = situation that Brad Simmons discovered. 144 dC fuses are available at = Radio=20 Shack, and would fail at 291 dF. This is slightly above the prepreg cure = temp of=20 270 dF that Lancair mentions for the Legacy. They imply the = other=20 models are cured under the same conditions but the factory should be = able to=20 confirm that.
 
  Lancair's website also = states that the=20 IV materials strength and stiffness was tested at 170 dF. = Perhaps a=20 fuse designed for a temperature between 170 and 270 dF would give = warning when=20 there was still an adequate reserve of strength while reducing the=20 possibility of a false alarm.
 
  In addition I have read = that titanium=20 is difficult to machine because it doesn't transfer heat easily. For = example,=20 the heat from drilling a hole tends to build up rather than dissipate = into the=20 surrounding metal so the use of coolant is required. Low heat transfer = is what=20 we're looking for in this application- has anyone considered using = it as a=20 shield for fiberfrax or the blanket?   -Bill Wade

We are in the process of repairing a IVP = engine fire=20 that was centered on the passenger aft side of the engine compartment, = and the=20 firewall blanket just barely did it's job. There is signifigant = scorching=20 around the perimeter, through every penetration, and around the cowl = attach=20 flange.
 
Brad Simmons
Airframes Inc.
Milan, 
 
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