Fire Sleeving?

[TXFlyGuy]

Originally Posted by Captain Avgas

I recommend firesleeving both the flexible fuel AND oil lines. Both are important. If you have a FWF fuel fire in flight you can turn off the fuel at the selector and possibly starve the fire ....not so with an oil fire. Even if you've killed the engine, if the prop continues to windmill the engine will continue pumping out oil to feed the fire. You just can't turn the oil supply off in the air. And oil fires produce more smoke than fuel fires and it will most probably be the smoke coming back through the firewall that will incapacitate you in flight before the fire does.

Good advice. Thanks.

[Tbone]

Originally Posted by sglynn

Sorry but the purpose of the fire sleeve is not to protect but to soak up fuel if a line leaks. The inner white cloth absorbs fuel in case a line leaks and prevents it from running lose in the engine compartment and catching on fire.

So yes on all fuel lines including around the RedBox.

That's a new one. I have never heard that before.

[bobnoffs]

although i firesleeved my fuel lines i talked to someone who made a pretty good case not to. he said inspection is way better and if you are looking you will catch lines that are beginning to be not perfect rather than out of sight, out of mind. he said if a fire starts you are to be shutting off fuel supply immediately and the few feet of rubber fuel line burning will not contribute anything to the way bigger problems you have going on.

[Captain Avgas]

Originally Posted by sglynn

Sorry but the purpose of the fire sleeve is not to protect but to soak up fuel if a line leaks. The inner white cloth absorbs fuel in case a line leaks and prevents it from running lose in the engine compartment and catching on fire.

Please tell us where you got that information from ?

The primary reason for using firesleeve on fuel and oil lines is to protect the hose (for a limited period) in the event of a general FWF fire. But there are many other advantages including:

1. Protecting the hose from flames and hot gasses emanating from an exhaust failure.
2. Minimising the potential for vaporlock.
3. Providing the hose with additional abrasion resistance.
4. Preventing failing electrical components from arcing onto steel braided hose.
5. Ensuring longevity of the hose by protecting it from the accelerated ageing associated with extreme temperature cycling.

[Auburntsts]

Put me down as another who fire sleeved the fuel lines but not the oil lines. I did however fire sleeve my "red cube" fuel transducer as it is essentially part of the fuel line from the mechanical fuel pump to my throttle body (FI IO-540).

[Captain Avgas]

Originally Posted by bobnoffs

although i firesleeved my fuel lines i talked to someone who made a pretty good case not to. he said inspection is way better and if you are looking you will catch lines that are beginning to be not perfect rather than out of sight, out of mind. he said if a fire starts you are to be shutting off fuel supply immediately and the few feet of rubber fuel line burning will not contribute anything to the way bigger problems you have going on.

The person you spoke to is horribly misinformed and his advice to you is dangerous and goes completely against aviation best practice.

[Auburntsts]

Originally Posted by sglynn

PER YOUR REQUEST TO EXPLAIN FURTHER
My A&P/IA for my Cherokee told me this. He has 40,000 hours in cockpit and a lifetime of A&P work. His father got his license in 1916, barely after the Wright Brothers.

It is logical. He says the most likely scenario is leaky fitting or line crack and fuel needs to be souped up, rather than dripping around. Maybe there are other functions. But fuel hoses have stainless steel mesh with conductive lining. Do they need abrasion protection? Static protection? Aging protection? Really?

Leaking fuel needs to be treated. Leaking fuel needs to be kept from igniting. Thus fire sleeve. When fuel leaks then it needs to be protected from igniting. Sleeve soaks it up and protects the fuel fluid from ignition sources. And so I suppose you can think of the pyro resistant silicone rubber cover as protecting the line from heat, but that isn't necessary until there is a leak. So what is the sleeve doing? It is protecting the leaking fuel from being ignited by soaking it up to prevent dripping and keeping heat away from it. It is not protecting a stainless wrapped, conductive teflon line.

Point is, when do you need fire sleeve? When the potential for a leak to ignite is a potential? Is the potential to ignite exist in the cabin? No. So we don't use it. But could fuel touch something hot in the engine compartment? Yes, so we use it there to prevent fuel from ignition heat source.

If fuel lines/fittings never leaked you wouldn't need fire sleeve.

Well OK but there's other ways a fire can start FWF that doesn't involve a leaking line. Believe what you want but I'm of the belief fire sleeve is there to protect lines from heat not to sop up gas from a compromised line that has a hole in it. Unless the line fails from the inside, anything that punctured the line would also puncture the fire sleeve as well.

To put this to rest I think we need some sort of actual reference to back up your supposition. not some A&P's opinion, regardless of how long they've been around the block. You and he may indeed be right, but I personally need to see it writing.

[JonJay]

I think it is a good recommendation to fire sleeve both oil and fuel. However, Van's "standard", unless they changed things in their FFW kits, has been fuel lines only.

[Jrskygod]

The main purpose for the fire sleeve is to hopefully buy enough time to extinguish the fire before the lines are compromised and contribute additional fuel to the fire and/or possibly to get on the aircraft on the ground, althought not likely. Everything else it does is superfluous. When the fire is melting the soles off your shoes is probably not a good time to decide that you probably should have sleeved both the fuel and oil lines. Fires are rare but when they do happen they can do unbelievable damage in an incredibly short period of time. After seeing what a fire did to a turbo 310 once made a believer out of me. Only you can decide how much time you want to buy.

PS: When my fuel line starts leaking I really hope the fire sleeve does a really good job of soaking up the gas so it doesn't drip on the exhaust. !!!!!!!!!!!! LOL

[Auburntsts]

FWIW, I just completed a little internet research and looked up a number of aerospace fire sleeve manufacturers and all of the product descriptions focused on their ability to withstand heat:

Here's a typical excerpt: "Our firesleeve sleeve, jacket, tape and fabric products are perfect for protecting hydraulic hoses, pneumatic lines, electrical cables, control wiring, welding cables, electric arc furnace cables, etc., from high-temperatures, heat, flame & pyro exposure, molten metal splash, slag, welding splatter, grinding & electrical sparks and environmental contaminations."

Some even specifically mentioned that their silicone coated fiberglass sleeves were designed to not absorb flammable contaminants. None touted their ability to absorb gasoline in the event of a leak as a product feature.

I also took a look at TSO-C53a, Fuel And Engine Oil System Hose Assemblies, and TSO-C75, Hydraulic Hose Assemblies, and it's clear to me the primary purpose of fire sleeve is to protect hoses from excessive heat. YMMV.....