X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 21 Nov 2005 21:06:54 -0500 Message-ID: X-Original-Return-Path: Received: from [64.12.137.3] (HELO imo-m22.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.0.2) with ESMTP id 842266 for lml@lancaironline.net; Mon, 21 Nov 2005 20:25:29 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.3; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m22.mx.aol.com (mail_out_v38_r6.3.) id q.157.5ce603be (17377) for ; Mon, 21 Nov 2005 20:24:37 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <157.5ce603be.30b3cd55@aol.com> X-Original-Date: Mon, 21 Nov 2005 20:24:37 EST Subject: Re: [LML] Re: Exhaust leak X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1132622677" X-Mailer: 9.0 SE for Windows sub 5021 X-Spam-Flag: NO -------------------------------1132622677 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 11/21/2005 11:34:07 AM Central Standard Time, marv@lancaironline.net writes: Sucking flames and smoke into the cabins on Velocity is usually not a problem. In most cases, the fire just burns until the engine falls off (only semi-joking). This is why many, including myself, have a fire detection system on the pusher that signals or alarms up front when the fire in back is not contained inside the six cylinders. You tractor guys are lucky, you get a face full of smoke and flames, so you know what's going on (only semi-joking). Different smoke, for different folks. Chuck, Verrrry Interrrrresting! Ya, we just wait 'till our feet get hot! The manufacturer of one of the new VLJs has developed a very compact fire supression system. The cartridge is the size of a 35mm film container and is equivalent to a quite large Halon system. I can't remember which manufacturer (the source was either AvWeb, Aero News, or AOPA Pilot) but I hope they will make the system available to the experimental aircraft community. All joking aside, the lower cowl area of down draft cooled engines typically seems to be 2-3 inches of H20 pressure higher than ambient (static) and the cockpit runs 2-5 inches of H20 pressure lower than ambient. The difference is 4-8 inches between the cockpit and the lower cowl area - independent of whether the engine is in the front or the back. In rear engined canard airplanes, the cockpit exit air travels down the spar in the strake or exits via some sort of vent behind the pilot area. That does not mean the flames or CO can't mix with cockpit air - maybe it will get the rear seat occupants first. Again, there is no high performance composite airplane that I know that has a higher pressure in the cockpit than ambient. Up draft cooled rear-mounted engines typically have fresh cooling air circulating around the firewall - good for reducing the CO problem, but even more dangerous with a fire from, say an oil line, since the pressure between the cooling plenum and the cockpit is even higher! Scott Krueger AKA Grayhawk LNC2 N92EX IO 320 SB 89/96 -------------------------------1132622677 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 11/21/2005 11:34:07 AM Central Standard Time,=20 marv@lancaironline.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Sucking=20 flames and smoke into the cabins on Velocity is usually not a
=20 problem. In most cases, the fire just burns until the engine falls=20 off
(only semi-joking). This is why many, including myself= ,=20 have a fire
detection system on the pusher that signals or alarm= s up=20 front when the
fire in back is not contained inside the six=20 cylinders. You tractor
guys are lucky, you get a face full= of=20 smoke and flames, so you know
what's going on (only=20 semi-joking).

Different smoke, for different=20 folks.

Chuck,

Verrrry Interrrrresting!

Ya, we just wait 'till our feet get hot!

The manufacturer of one of the new VLJs has developed a very compact fi= re=20 supression system. The cartridge is the size of a 35mm film container=20= and=20 is equivalent to a quite large Halon system. I can't remember which=20 manufacturer (the source was either AvWeb, Aero News, or AOPA Pilot) but I h= ope=20 they will make the system available to the experimental aircraft=20 community.

All joking aside, the lower cowl area of down draft cooled=20 engines typically seems to be 2-3 inches of H20 pressure higher than=20 ambient (static) and the cockpit runs 2-5 inches of H20 pressure lower than=20 ambient. The difference is 4-8 inches between the cockpit and the lowe= r=20 cowl area - independent of whether the engine is in the front or the back.&n= bsp;=20 In rear engined canard airplanes, the cockpit exit air travels down the spar= in=20 the strake or exits via some sort of vent behind the pilot area. =20= That=20 does not mean the flames or CO can't mix with cockpit air - maybe it will ge= t=20 the rear seat occupants first. Again, there is no high=20 performance composite airplane that I know that has a higher pressure in the= =20 cockpit than ambient.

Up draft cooled rear-mounted engines typically have fresh cooling air=20 circulating around the firewall - good for reducing the CO problem, but even= =20 more dangerous with a fire from, say an oil line, since the pressure between= the=20 cooling plenum and the cockpit is even higher!

Scott Krueger=20 AKA Grayhawk
LNC2 N92EX IO 320 SB=20 89/96

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