Firewall insulation

[DanH]

Originally Posted by MikeT

DanH, do you have any experience with this?
http://www.aircraftextras.com/Contego.htm
The product looks good if it works as stated.

http://www.vansairforce.com/communit...7&postcount=37

[chunt0]

Dan, any thoughts about piggybacking sound insulation on the cool side of good firewall heat insulation? Along the same lines, how about putting a bit of thin ceramic insulation under floor pads/carpeting?

[glenn654]

Thankfully I have no experience with this but about how quickly can you tell if there is an engine fire when cruising along?

I suspect that it is possible to fly without noticing longer than some of the speculation (within a minute or less).

Does anyone have any experience with this sort of thing?


Glenn Wilkinson

[LettersFromFlyoverCountry]

Originally Posted by DanH

All firewall penetrations should be steel or insulated/protected.

Not to hijack the thread but since you brought it up: The 7A plans say to drill a hole for the hinge pins on the side of the cowling to support the part of the cowlings that aren't hinged to the firewall. This would seem to defeat the point of sealing up the firewall (or are people somehow sealing up this hole in a way that makes removing the hinge possible?)

Also regarding "mechanical method of attachment": What are people using to accomplish attaching this material to the firewall. As near as I can tell, it would take several pieces to fit into the various crevices etc.

[Lars]

Originally Posted by glenn654

Thankfully I have no experience with this but about how quickly can you tell if there is an engine fire when cruising along?

I suspect that it is possible to fly without noticing longer than some of the speculation (within a minute or less).

Does anyone have any experience with this sort of thing?


Glenn Wilkinson

This has been posted before, but it's worth another look:

http://www.ntsb.gov/ntsb/GenPDF.asp?...99LA063&rpt=fa

That happened close to me. The pilot was well-known and widely respected in our local homebuilt and acro community. It didn't take long at all for that engine fire to bring him down.

I happen to work with a bunch of pilots; there is still a photo of him next to his plane hanging in our shop. We keep it there in part as a reminder to not be cavalier about those systems that could lead us to a similar demise.

For what it's worth, it was apparently the burning insulation on the cabin side of the firewall that overcame him and caused his mortal injuries.

[DanH]

Originally Posted by chunt0

Dan, any thoughts about piggybacking sound insulation on the cool side of good firewall heat insulation? Along the same lines, how about putting a bit of thin ceramic insulation under floor pads/carpeting?

Charlie, it is possible, but the devil is in the details. First you would need a fire insulation system that maintained structure temperatures below the smoke and ignition temperature of the sound insulation at every point it contacts. As a practical matter that is a difficult design task. Here's an example.



The burner has been running 5 minutes in this shot. The panel is faced on the "engine" side with an effective insulator and SS foil. The aluminum angle (same size as a Vans firewall) in this test panel is holding at a reasonable temperature. However, see the AN3 nut and bolt to the right of the instrument, just above my thumb? It was installed in the test panel to check heat transmission via a point source. Its temperature is well above the measurement capability of the Raytec. You can't see it in the photo, but that AN3 is glowing a very dim red.....more than hot enough to ignite plastic or rubber sound insulators.

FWIW, my own firewall is bare metal on the cabin side....not even paint, exactly like the test panel you see here.

Complete link for the accident referenced by Lars:
http://www.ntsb.gov/_layouts/ntsb.av...99LA063&akey=1

[mculver]

Alas, the photos in this thread are no longer available. Anyone (Dan?) able to re-post them an update the thread?

Thanks!

Mike

[vfrazier]

Mike, try again. I was able to see all of the photos today, and on a computer that i have never used before, so they were freshly downloaded.

[stamper]

I bought another piece of stainless steel and made a duplicate of my firewall, put my insulation blanket that was 1/8" thick and rated to 2500 degress and sandwiched the fiberglass between the two pieces of stainless steel and sealed the perimeter. I did this from the engine side. I cut out the insulation/fire Barrier out where the engine mount bolted up so that it would be solid. It worked great and best of all it loooks good.