X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 30 Dec 2010 20:09:14 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-kukur.atl.sa.earthlink.net ([209.86.89.65] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4658386 for lml@lancaironline.net; Wed, 29 Dec 2010 22:59:45 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.65; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=BsaGEkIqEHT7NFsgX9Q7n1QhDx8G0LwAqs1+41crOwPVdaGyag+h3Ow+JW5PlF9K; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.85] (helo=[192.168.1.103]) by elasmtp-kukur.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1PY9fT-0003i7-LA for lml@lancaironline.net; Wed, 29 Dec 2010 22:59:12 -0500 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: multipart/alternative; boundary=Apple-Mail-238--305745437 Subject: Re: [LML] Re: post crash fire control X-Original-Date: Wed, 29 Dec 2010 22:59:10 -0500 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: X-Mailer: Apple Mail (2.1082) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940cd8b88ef370a6a3d964d6589ad1e6e89350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.85 --Apple-Mail-238--305745437 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Rob, interesting info. So sounds like if you do have a quick drain, you don't want to = completely empty it. I have no idea how to build a quick drain that would not create some = leakage risk. sounds like you are in this business? Lorn, I haven't contacted crestfoam. Was just pointing at them as an = example. Apparently flexible foam is pretty standard for flexible race car tanks. = I'm not sure why it's a better match there but it may have to do with = the fact that the tank itself is flexible and that you are likely to = cause collateral damage if you leave fuel on the track. Colyn On Dec 29, 2010, at 9:21 PM, REHBINC wrote: > If foam is used in the tanks, it will reduce the amount of ATOMIZED = SPRAY produced by a crush/rupture of the fuel tank. This will help to = reduce the chance of ignition, but not greatly as fuel will still = trickle rapidly from the foam filled tank and quickly generate a = flammable vapor in the area. In the event of significant travel after = catastrophic tank failure, the foam could well make matters worse for = the occupants as it would retain significant fuel for a short time. = Without the foam, this fuel could be left behind, reducing the fire load = at the point the aircraft comes to rest. > =20 > Personally, I don't think foam is a worthwhile investment as a fire = prevention tool in an aircraft. (At least for wing tanks) In my opinion, = a better use for foam is to reduce slosh in the tank. > =20 > The fuel dump idea makes much more sense to me. Sure the introduction = of large quantities of air into the tank would result in a flammable = vapor, but the failure pressure of the wing structure would be = relatively low so the shock wave would be low as well. Ignition probably = would not occur until after the tank was significantly ruptured anyway, = so the confinement would be even less. Also the fiberglass/carbon = wouldn't result in high energy missiles like heavier metals would, so = the shrapnel danger would be lower as well. > =20 > Finally, our testing on large tanks has shown that residual fuel in = the bottom of a recently emptied tank generates a fuel rich/nonflammable = layer in the bottom of the tank at a rate of about one foot per hour. = Given the shallowness of a Lancair wing, a significant portion of the = vapor space would likely be made nonflammable between the time the fuel = was dumped and impact occurred. > =20 > That's my two cents worth, > =20 > Rob > =20 > In a message dated 12/28/10 21:53:45 Eastern Standard Time, = colyncase@earthlink.net writes: > I'm wondering if anyone has researched/thought about fuel containment = in the event of a crash.=20 > For example, I have foam in my aux tank because it was made by fuel = safe and that's just the way they make their tanks. I didn't put any = foam in my main tanks. But here's a possibility:=20 >=20 > http://www.crestfoam.com/intro.html=20 >=20 >=20 > A fuel dump option might also be interesting but that leaves highly = explosive fumes in the tanks.....=20 >=20 > thoughts?=20 >=20 > Colyn=20 >=20 >=20 > --=20 > For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html=20 > =20 --Apple-Mail-238--305745437 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Rob, =   interesting info.
So sounds like if you do have a quick = drain, you don't want to completely empty it.
I have no idea = how to build a quick drain that would not create some leakage = risk.
sounds like you are in this = business?


Lorn,   I haven't = contacted crestfoam.   Was just pointing at them as an = example.

Apparently flexible foam is pretty = standard for flexible race car tanks.  I'm not sure why it's a = better match there but it may have to do with the fact that the tank = itself is flexible and that you are likely to cause collateral damage if = you leave fuel on the = track.

Colyn

On Dec 29, = 2010, at 9:21 PM, REHBINC wrote:

If foam is used in the tanks, it = will reduce the amount of ATOMIZED SPRAY produced by a crush/rupture of = the fuel tank. This will help to reduce the chance of ignition, but not = greatly as fuel will still trickle rapidly from the foam filled = tank and quickly generate a flammable vapor in the area. In the event of = significant travel after catastrophic tank failure, the foam could = well make matters worse for the occupants as it would retain significant = fuel for a short time. Without the foam, this fuel could be left behind, = reducing the fire load at the point the aircraft comes to = rest.
 
Personally, I don't think foam is a = worthwhile investment as a fire prevention tool in an aircraft. (At = least for wing tanks) In my opinion, a better use for foam is to reduce = slosh in the tank.
 
The fuel dump idea makes much more = sense to me. Sure the introduction of large quantities of air into the = tank would result in a flammable vapor, but the failure pressure of the = wing structure would be relatively low so the shock wave would be low as = well. Ignition probably would not occur until after the tank was = significantly ruptured anyway, so the confinement would be even = less. Also the fiberglass/carbon wouldn't result in high = energy missiles like heavier metals would, so the shrapnel danger would = be lower as well.
 
Finally, our testing on large tanks = has shown that residual fuel in the bottom of a recently emptied tank = generates a fuel rich/nonflammable layer in the bottom of the tank at a = rate of about one foot per hour. Given the shallowness of a Lancair = wing, a significant portion of the vapor space would likely be made = nonflammable between the time the fuel was dumped and impact = occurred.
 
That's my two cents = worth,
 
Rob
 
In a message dated 12/28/10 21:53:45 Eastern Standard Time, colyncase@earthlink.net = writes:
I'm wondering if anyone has researched/thought about fuel containment in = the event of a crash.
For example, I have foam in my aux tank = because it was made by fuel safe and that's just the way they make their = tanks.    I didn't put any foam in my main tanks.   But = here's a possibility:

http://www.crestfoam.com/intr= o.html


A fuel dump option might also be interesting but = that leaves highly explosive fumes in the tanks.....

thoughts? =

Colyn


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