Fire Resistant Fuel Tank?

[rgmwa]

Has anybody considered painting the exterior of the fuel tank with intumescent (fire-retardent) paint?

It wouldn't do much good if the tank ruptured in a crash, but (assuming the perspex sight holes had been plated over) it might delay a post-crash fireball long enough to give you a better chance of getting out, or for help to get to you if you were knocked unconscious.

Just a (depressing) thought.

 

[DHeal]

How about an internal fuel cell or bladder? You would lose some capacity and gain some weight and cost, but ....

 

[terrye]

Fuel Tank

If you look at helicopters, military aircraft and race cars you can trace the evolution of puncture/accident resistant, spill resistant tanks. Some of the evolution stages are aluminum tanks (riveted or welded), self sealing tanks with an internal coating, rubber bladder type tanks which are deformation damage resistant, and rubber bladder type tanks filled with explosion resistant foam baffling.

The aluminum tanks were fairly safe after impact until they were punctured, at which point they became fairly dangerous. The current bladder tanks with explosion resistant foam baffling contained in a crashworthy metal container are unbelivably effective in preventing fuel spills/fire/explosion after an impact.

I'm sure one could be fitted inside the current RV-12 fuel tank. The down side is extra weight, extra cost and slightly reduced fuel capacity.

ATL is one of the world leaders in the field.
http://atlinc.com/index.html

 

[rgmwa]

Good point Terrye. An internal bladder would be the way to go, since what you really want in a crash is to maintain the integrity of the tank so the contents stay inside.

Intumescent paint won't help you there. It also needs heat to activate, which means a nearby fire source, and that means you're probably already in serious trouble. It's only advantages are that it wouldn't affect the E-LSA status, doesn't reduce the already not overly generous tank capacity, adds negligible weight, and probably wouldn't cost much. However, it probably wouldn't help you much in a crash either.

My thought was prompted by an accident in Australia yesterday where a new experimental plane took off on its first first flight, got a few metres off the ground, rolled suddenly, crashed and went up in flames. Fortunately the pilot managed to get out quickly, but not before receiving 75% burns. Apparently that plane's fuel tank was in the nose behind the engine and above the pilot's knees.

At least in the RV-12, the tank is probably in a safer location, being further back from the pointy end, and probably better protected inside the cabin. I just hope it's well bolted down so it stays there on impact. That piece of perspex covering the sight holes worries me though. I don't think that's a good design feature. Solid metal looks much better!

 

[rjtjrt]

I had a brief look at the possibility of explosion resistant foam baffling.
However in the site I looked at it said the foam needs to be changed after a few years as it degrades and it can enter the fuel in particles, I seem to recall (I stand to be corrected in this).
This sounded like an inconvienience in a racing car, but a bit more than an inconvienience in an aeroplane.
I have been impressed by the dictum tobe very careful/reluctant to modify fuel systems or flight controls in a successful design.
Thus i am a littleconcerned re fuel in cockpit and would like to put in a largerv tank with fire resistant foam, but am a bit aprehensive it may be possibe to cause more danger than it cures.
John