X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [206.46.252.40] (HELO vms040pub.verizon.net) by logan.com (CommuniGate Pro SMTP 5.0c1) with ESMTP id 680405 for flyrotary@lancaironline.net; Wed, 24 Aug 2005 11:00:00 -0400 Received: from verizon.net ([71.99.195.153]) by vms040.mailsrvcs.net (Sun Java System Messaging Server 6.2 HotFix 0.04 (built Dec 24 2004)) with ESMTPA id <0ILQ004X3EZWJG84@vms040.mailsrvcs.net> for flyrotary@lancaironline.net; Wed, 24 Aug 2005 09:59:56 -0500 (CDT) Date: Wed, 24 Aug 2005 10:59:54 -0400 From: Finn Lassen Subject: Re: [FlyRotary] Re: Fire extinguishers In-reply-to: To: Rotary motors in aircraft Message-id: <430C8B6A.9070208@verizon.net> MIME-version: 1.0 Content-type: multipart/alternative; boundary=------------030504080604010606000506 X-Accept-Language: en-us, en References: User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax; PROMO) This is a multi-part message in MIME format. --------------030504080604010606000506 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit I think someone made the point that a fiberglass cowling is probably the first thing to go (burn. melt) so what would be the point? If you could act fast enough it would be a good idea. However, designing a system that would work and not cause trouble in normal flight by suddenly closing by itself and killing the engine might be tough. Finn Lawrence E Mac Donald wrote: >As of yet, no one has come up with the notion of a >lever (cable) operated set of doors that would block >the air intakes of the cowling so that a fire >extinguisher would work. >Or is that a bad idea ? >Larry Mac Donald >Rochester N.Y. >Do not archive > > >On Wed, 24 Aug 2005 19:42:29 +1000 "Michael Burke" > writes: > > >>>the only way to keep the fire out is to keep the air out >>>being able to shut the cooling air flow, at the exit or intake will >>> >>> >>help a >>lot. >> >>I'm trying to put this in perspective. >>Assuming no way to shut off the intake air, is firing a halon >>extinguisher >>in flight going to have ANY worthwhile impact on an engine fire? >>Keep in >>mind that the fibreglass cowl is likely to be breached early on, >>thus any >>control of airflow is lost. I'm beginning to think that the most >>important >>issues here are detection, and removal of the source (fuel) and that >>an >>extinguisher would be useful to save the plane once landed, but >>worthless >>(and wasted) if used while airborne. >> >>Thinking of fire makes me glad I built a pusher. >>John >> >>Yes John, early detection is vital so a heat sensor, naked flame >>detector is >>vital as is an ambient under cowl temp sensor. First one will detect >>the >>fire, and the second one will tell you how hot things are getting, >>and most >>important tell you when the fire has gone out. >> The very best strategy is in aircraft design. You need cowl >>flaps for >>BOTH inlet and air outlet points, so that you have total control of >>the >>airflow through the cowl. There are two main reasons for this. >>1) If you can control the air flow, you CAN control the fire, you >>starve it. >>Believe me it works. Why do commercial kitchens have fire blankets. >>2) When you fire off your halon extinguisher, you want to hold that >>cloud of >>halon under the cowl for as long as possible. If there is no air >>flow it >>ain't going any where fast, and secondly and most importantly as >>long as you >>have that halon cloud under the cowl, there is a very low >>probability of >>re-ignition. this can buy you very valuable time to find a safe >>landing >>area. >> Other design factors are, a decent size drip tray and hear >>barrier >>between the fuel rail and the exhaust port outlets. Don't allow fuel >>to drip >>or spray onto a hot exhaust. Second, shield the exhaust pipe/s from >>shooting >>a hot flame onto any fibreglass surface. Easier said than done I >>know, but >>if it can be done it should. Otherwise experiment with industrial >>fire proof >>matting on the inside surfaces of your cowl. >> An extinguisher that you can control, and that has enough >>reserve so >>that you can fire off 50% to 60% initially, and then two or three >>bursts >>three or four minutes apart. This tops up the level of halon under >>the cowl, >>and buys you very valuable time. >> Fires can be managed, but like everything else, its a lot easier >>if you >>design for them in the first place, and have a sound fire drill to >>put into >>action. >>Safe flying guys >>Michael Burke >>Australia >> >> >>-- >>Homepage: http://www.flyrotary.com/ >>Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >> >> >> > > >-- >Homepage: http://www.flyrotary.com/ >Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > > > --------------030504080604010606000506 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit I think someone made the point that a fiberglass cowling is probably the first thing to go (burn. melt) so what would be the point?

If you could act fast enough it would be a good idea. However, designing a system that would work and not cause trouble in normal flight by suddenly closing by itself and killing the engine might be tough.

Finn

Lawrence E Mac Donald wrote:
As of yet, no one has come up with the notion of a 
lever (cable) operated set of doors that would block 
the air intakes of the cowling so that a fire 
extinguisher would work. 
Or is that a bad idea ?
Larry Mac Donald
Rochester N.Y.
Do not archive


On Wed, 24 Aug 2005 19:42:29 +1000 "Michael Burke"
<mburke@southernphone.com.au> writes:
  
the only way to keep the fire out is to keep the air out
being able to shut the cooling air flow, at the exit or intake will 
      
help a
lot.

I'm trying to put this in perspective.
Assuming no way to shut off the intake air, is firing a halon 
extinguisher
in flight going to have ANY worthwhile impact on an engine fire? 
Keep in
mind that the fibreglass cowl is likely to be breached early on, 
thus any
control of airflow is lost. I'm beginning to think that the most 
important
issues here are detection, and removal of the source (fuel) and that 
an
extinguisher would be useful to save the plane once landed, but 
worthless
(and wasted) if used while airborne.

Thinking of fire makes me glad I built a pusher.
John

Yes John, early detection is vital so a heat sensor, naked flame 
detector is
vital as is an ambient under cowl temp sensor. First one will detect 
the
fire, and the second one will tell you how hot things are getting, 
and most
important tell you when the fire has gone out.
    The very best strategy is in aircraft design. You need cowl 
flaps for
BOTH inlet and air outlet points, so that you have total control of 
the
airflow through the cowl. There are two main reasons for this.
1) If you can control the air flow, you CAN control the fire, you 
starve it.
Believe me it works. Why do commercial kitchens have fire blankets.
2) When you fire off your halon extinguisher, you want to hold that 
cloud of
halon under the cowl for as long as possible. If there is no air 
flow it
ain't going any where fast, and secondly and most importantly as 
long as you
have that halon cloud under the cowl, there is a very low 
probability of
re-ignition. this can buy you very valuable time to find a safe 
landing
area.
    Other design factors are, a decent size drip tray and hear 
barrier
between the fuel rail and the exhaust port outlets. Don't allow fuel 
to drip
or spray onto a hot exhaust. Second, shield the exhaust pipe/s from 
shooting
a hot flame onto any fibreglass surface. Easier said than done I 
know, but
if it can be done it should. Otherwise experiment with industrial 
fire proof
matting on the inside surfaces of your cowl.
    An extinguisher that you can control, and that has enough 
reserve so
that you can fire off 50% to 60% initially, and then two or three 
bursts
three or four minutes apart. This tops up the level of halon under 
the cowl,
and buys you very valuable time.
    Fires can be managed, but like everything else, its a lot easier 
if you
design for them in the first place, and have a sound fire drill to 
put into
action.
Safe flying guys
Michael Burke
Australia


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