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firey crash

wadecalvin

Registered User
Oregon
Is there anything you can do to a cub to make it less apt to burn in a crash? My brother was burned bad when a tank dumped on him in a crash - I've read on this site that tip tanks are mostly obsolite but it sure would seem safer if the tanks were further away from the pilot in an accident.

Timm
 
wadecalvin,

A Cub has fuel all over in the cabin area, as do most light aircraft. Right up behind the instrument panel there is a header tank. Right over your head on either wing root, there are glass sight gauges full of fuel. On your left, there are fuel lines running to the fuel selector.

Some folks have removed the header tanks and gone to a four position fuel selector-there's an stc for that mod. One of the arguments for that mod is that it gets the header tanks out of the cabin.

If you have stock header tanks, you can replace them (should replace them, perhaps) with the heavier duty ones from Atlee Dodge.

No way I'm aware of to move all the fuel out of the cabin, though.

Best answer: Don't crash.

Again, note that these are not exclusive to Cubs.

While fires do occur, they are pretty rare. You only need one, though, to really mess up your life.

MTV
 
I am glad to hear your brother made it. I hope he is doing okay with the aftermath...

I know 2 guys who survived a Supercub crash and fire. They hit a tree and came to a rest. They were dazed sitting in the plane for probably a couple of seconds before they realized gas was coming in on them from the wing root. The next thing they heard was wooof! and they were on fire. The guy flying got it bad 2nd-3rd degree burns over 50%.. Then they walked 5 miles over the tundra to a village.

I say all this because it is my biggest fear. I've heard of eliminating the header tank; another idea of trying to seal the tank in the wing root with some sort of rubber, aluminum, of foam and then using a PA-12 style sight gauge (but this would be experimental). I think if you just keep the gas out of the cabin you got a chance but a lot of guys have not been that lucky.
 
Fire

Fire sure is a heart breaker. The only thing I might add is don't for the spark side of the fire equation. Many aircraft wiring jobs are quite inadequate. Getting the wiring out of the wing root is a good start. Then examine all connections and see how sturdy and protected they are. Wires should have some slack to allow movement. The battery should be secure and the positive termal protected.

Good luck to your friend in his recovery.

Jerry
 
I bet we could make a list that would make a supercub much less prone to crash related fire.

1. Eliminate the glass site glasses for one and rely on a digital counter.

2. Protect the positive terminal,overkill I mean, and the hot leed to solinoid

3. Get rid of the header tank.

4. Recheck all primer assembles and secure with a crash in mind


5. get rid of hose clamps and rubber hoses, hard point type of lines and connections

I am sure some little things might make the difference.



add to the list any one.
 
Fiery Crash

I share the same concern having seen the carnage. Lost two buddies. Kase has posted the photos before.

Where do the lines rupture in a wreck, or is it just the tanks? Should be enough research out there to know most likely spots to work on first. Technology could move us forward...at a cost...weight, money, complexity, etc

1) Why not do like the race cars? Carbon fiber tanks with auto-shut off when line ruptures. Cruise the following website and let your mind go. www.fuelsafe.com/custom.htm

2) Electronic interrupt installed between ground and battery with switch/circuit breaker that activates with g loads like ELT does.

3) Firesleeve all fuel lines
 
I believe some of the newer cars have a impact electric shut off in the battery line that might work. That does seem like a good idea. I believe i'll look into it.
 
good answers

Good answers all. Thanks I'll keep track of the suggestions on this post. We celebrated the eighteenth aniversary of the crash this month. 3 degree burns over 70 percent of his body. Unfortunately my whole family (except me) witnessed it. He still flies but is more cautious. The airplane went down in timber and Oddly enough he was headed between two trees that would have broken the wings off but the tires his a patch of rough ground which stopped the airplane hard and the wings broke off bass ackwards and dumped one of the tanks on him. As a side note, everywhere he had two layers of clothing was protected - high boots, neckerchief, hat, breifs (thanks God). Makes a guy want to rush out and invest in asbestos longhandles.

Be carefull

wadecalvin
 
One other commonly overlooked area for a fire hazard is the wire baled original gascolator. When the left side of the belly hits the ground the first thing to go is the bowl off the gascolator spilling fuel down into the hot engine area. That is one advantage of our design, it can take a considerably harder impact before the bowl is dislodged. It is more likely that the fuel lines will be torn loose before our unit breaks.
Steve
 
fiery crash

Don't know enough about engineering, and it depends on the impact, but if there is an area where lines generally rupture, how about a sacrificial connection attached to a quick connect like we use on our air compressor lines? Once a certain force is applied, the connection comes apart, sealing the tank side. Hmmm. I'll have to ask Gunny what scotch he drinks. Mine might be a tad strong right now.
 
Thanks, Randy. One more proof that, though the flesh is fragile, the spirit is indestructible.
 
Of course, you can also look at the pilot in this conversation. What's he or she wearing? Polypro will melt and stick to your burns, and is a nightmare to remove.

Nomex long johns in cold weather work well, are warm, and might save you from some burns. Nomex flight suits and insulated coats are readily available as well.

Same with gloves. Leather shoes, preferably boots will save your feet.

I don't wear this stuff all the time, but a fair amount at work. It's pretty cheap insurance, and not uncomfortable.

If you can't fireproof the plane, maybe you should look to the pilot as well.

MTV
 
Fire

Fire is fearful, no question.

Condolences to all who have been burned or who have loved ones who have.

However: Beautiful, simple, perfectly informative sight guages in the Super Cub have kept more pilots alive with specific knowledge of fuel remaining or not remaining than they have killed or injured as the source of fuel to feed a fire in a crash.

Bob Breeden
 
Bob,

Actually, I've never met a fuel gauge I trust in an airplane, even sight gauges. They all can have anomalies and quirks.

Still, your point is well taken, in that post crash fires are pretty unusual, and you have to decide what is a reasonable level of protection in one realm, vs the risk involved.

There simply isn't a small airplane around that can't douse the occupants in fuel pretty quickly if the wrong set of circumstances presented themselves.

I do agree that, of all the airplane gas gauges I've been around, sight gauges are maybe the most reliable.

I still like the small fuel computers now available, though. But, garbage in garbage out, as they say.

MTV
 
I think the big reason Cubs burn is all that stinking electrical in the wing root. Had a friend who splashed himself and the tanks like a watermelon, but didn't burn. Of course it doesn't really matter, cause dead is dead. All of his electrical was in the panel, and we think that had a lot to do with the lack of fire. We all miss ya Skip!
 
Nomex flight suit would be another idea, having crashed an airplane involving a fire (cropduster) with fertilizer and avgas as a good fuel I can say, that I will never spray again without a flight suit. Scary stuff!!
 
Getting roasted can happen to you even in a nice new modern aircraft. Lost two good friends in a Cirrus. When talking to the county coroner he said that the fire came up between the front two seats after the crash and burnt all the extremities to a degree that both guys were simply the size of a bag of cement.
 
When I bought my cub from his employer, the line patrol pilot that flew it all the time told me:" Cubs fly really good, but they burn really good, too, so don't ever let it crash sideways into a wingtip, as the tank will be pushed into the cockpit and break open over your head." I thought that was good advice,so when I pranged it at Mile Hi, I sacrificed the prop and engine to keep it going in a straight line(sort of)......no fire, anyway....
 
After having sprayed for 15 years with a "B" model Pawnee ( fuel tank in your lap) Fire was a great concern when I rebuilt my Super Cub. Considering the fact that this Cub was destined to be used lOW AND sLOW checking fiellds, Hunting Coyotes, survey work, etc., I took the fire danger very serious and made some improvements that minimize the risk of fire significantly. I incorporated a contactor type solenoid located adjacent to the under-rear seat battery to de-energize the entire Aircraft when shutting off the Master switch, Moved all electrical from wing root to the panel, installed CC headerless fuel system and mounted a small Halon fire extinguisher to a reinforced mount on the left wing root panel which is easily reached from either seat. Although I can't say I always wear nomex, I do normally wear leather boots, Nomex flight suit and gloves which are a requirement of some of our contracts, not a bad idea.

Ray
 
I've used the solenoid idea on my last several homebuilts, and always wondered if I'd remember to turn off the master in an emergency. A few years back, landing on a narrow, crowned dirt road at 7800' to check out a Idaho ghost town my attention wandered a bit and I got sucked into the barrow pit. As my left gear leg folded under (a beer cooler sized boulder) and I slowly went up onto the nose (by now going maybe 3 or 4 mph) I, to my great satisfaction, calmly reached out and flipped the master off. That almost made up for the screwed up landing! I always supposed a SC was set up that way, or any certified design, they are not??
 
So, why not make a device, a "G" switch, in series with the battery, that would disconnect everything when subjected to forward G's? You could seal it with inert gas, to prevent ignition, and oxidation of the contacts.... :-?
 
Steve,
Thanks for the great engineering on your STC'd gascolator. Every Piper should be flying with one. I put one on my -12, but am still perplexed by the line that runs into the top of the gascolator. It tee's in the headliner behind the windscreen and routes to ports on the forward top of each tank. There is no shut off for that line and when you go over on your back, now it is a low point on the tanks and can't be secured. Any thoughts???
Chris
 
fobjob said:
So, why not make a device, a "G" switch, in series with the battery, that would disconnect everything when subjected to forward G's? You could seal it with inert gas, to prevent ignition, and oxidation of the contacts.... :-?

THAT is a hell of an idea..... most cars with fuel pump in tank have a "crash" switch mounted in trunk area.... my old escort had one and with the bad/locked up shocks every big pot hole sent me coasting to the side of the road!....

its just a pendulum like thing... wounder how it would do with ruff landings/flights?

or better yet one like the elt's have, that is not a pendulum....

just have it in series with the small wire going to the master solenoid.... would need to be located near pilot so you could press reset button if it inadvertently got tripped.... and maybe an override position on master switch.....

hmmmmm.... that stack of now useless 121.5 elts might have some useful parts in them........
 
Having just re-read this thread, I notice that a battery cut-off was mentioned at least twice before I did....gotta quit reading this stuff late at night...
Gas pouring into the cabin from a ruptured tank or hose(?) seems to be a common thread, though, so I wonder how hard it would be to seal up the wing root? (Foaming the inboard edge of the tank, for instance....)
Also, I recall a fabric that could be stuffed into a fuel tank, that would prevent splashing the fuel on impact....maybe we just need tanks made from thicker metal and more baffles....
 
When I had to put my cub in (engine failure) I really balled it up, after the dust settled and I got my whits about me the doors were jammed, as was my right leg ( fuselage map pocket area folded in on my foot/leg) the left wing root separated sight glass broke and fuel spilled over my shoulder and back. NO FIRE, but the thought was there and I pounded the doors open and was able to crawl out.... I had No elect. system and as long as arm hold out I wont.... thought on cloths "CARHARTS" are sim. Heavy Canvas Cotton when ever you can. Kinda hard in Arizona in summer.

Stuff happens, we can do our best to prepare but ? It is easy for me to see how one can get trapped and things go bad real quick, I had never really given it that much thought before but now it's there in the back of my mind.

I agree with getting all the wiring away from roots, perhaps taking extra time and effort to encase/secure it in a safer manner. I know there's still alot of alum. battery cases out there, fiberglass would be better option.

Like one of you said "DON'T CRASH" I certainly didn't start the day with that in mind....crap just happens

I had Angels looking after me that day, NO doubt SO don't fly Faster than Your Angel can.....
 
wadecalvin said:
Is there anything you can do to a cub to make it less apt to burn in a crash? My brother was burned bad when a tank dumped on him in a crash - I've read on this site that tip tanks are mostly obsolite but it sure would seem safer if the tanks were further away from the pilot in an accident.

Timm

Don't fly it, then it won't crash?
 
For experimental folks, has anyone investigated the race car style fire extinguishers that flood the whole cabin?
 
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