Hi all:

 

I've never posted here before, and I'm not building a plane yet, but I thought I'd comment on this for what it's worth (I'm planning on building an RV-8A and I haven't decided on the engine to use yet).

 

All POHs for the certified planes that I've flown recommend a dive in case of a cowling fire (and cutting any fuel fed into the cowling).  These planes obviously don't have any means to close off the airflow into the cowling.  But the fire suppression is accomplished by making the mixture too lean within the cowling to support a fire, hence the dive.  I think my old Mooney recommended opening the cowl flaps too (it's been several years).

 

It would seem to me that it would be much harder to seal a cowl, especially since the cowl material is not likely to be very fire-resistant, than to blow the fire out, so to speak, by allowing a bunch of air in to make it too lean to burn.

 

I presently fly an Aerostar, which has fire detectors installed.  I understand that they can give false fire alarms, but that this is fairly rare.  In any event, I still have another engine running if I shut one down due to a false alarm.

 

Brad Gould

From: "Michael Burke" <mburke@southernphone.com.au>
Subject: Re: [FlyRotary] Re: Fire extinguishers
Date: Thu, 25 Aug 2005 16:05:05 +1000

Hi Larry,
I was thinking of the new streamline cowls that has one large opening at the
six o clock position. With the cooling rads slung under the engine, they can
be ducted through to the exit cowl at the rear. My idea, (probably many ways
to do it) would be to take the air for the engine compartment through an
opening at the top of the duct just inside the duct inlet. This opening
could then be controlled by a seperate flap, actuated from the cabin by a
push/pull cable that can be locked in both positions. I would imagine this
opening would not have to be very big, and if positioned properly should not
interfere with air to the cooling rads. It would give one the ability to
block inlet air to the engine without affecting the rads. The rads ducting
would have to be pretty airtight as would the cowling around the spinner.
That's the approach I'll be taking FWIW.
Michael Burke.
Australia.

Larry,
If you block both intake and outlet, the fire should die or be reduced to
nothing. Fire extinguisher on top will put it down.

On Aug 24, 2005, at 1:43 PM, 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.
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