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Another potential RV-10 fire averted!

pierre smith

pierre smith

Well Known Member
Since my cowl was off to have my alternator repared, I decided to sit on a bucket and just..."look things over"....carefully...oil lines first, then fuel lines, from one end to the other. I don't get shook up too quick but this one got my breath! I've been flying it like this, apparently since December!

The pressurized fuel line from the pump to the forward controller was lying against the hot exhaust, ahead of the muffler! The line was new in December from Tom at TS Flightlines...teflon lined, stainless braided and firesleeved.

It is burned all the way through the firesleeve to the braid:eek: Man-oh-man, is He watching over me or what!
Burnedfuelline.jpg


Guys, if you haven't had your cowls off in a while, stop what you're doing and look all your lines over with a fine-tooth comb....please!

Whew,
 
Blessings!

Wow, Pierre! Here's to broken alternators! And to the wisdom of your taking advantage of the opportunity you had to look deeper.

In the safety thread-storm going on right now, I'm hoping one of you experienced hands is eventually going to start a thread or two on FWF safety. I'm struck that this is one of the noted major areas of concern Van mentioned in his briefings, is one of Doug's special handling areas, but is the least understood and documented portion of the build for a neophyte like me.

There are obvious questions of FWF design, build standards, inspection, maintenance, repair--all missing in someone of my experience level. After two years of study while preparing to start my build in earnest, and even with an engineering degree in hand (albeit, in EE), nevertheless, I still feel woefully inadequate to the task of building and flying my powerplant.

--Stephen
 
Glad you caught that, Pierre. Presumably something sagged since originally installed, but even without sag, the picture looks like that would have been a logical place to have a heat shield anyway, no? (Sometimes pictures can be deceiving though.) Something to think about to perhaps save the new hose from a similar fate.
 
Pierre,

I make it a point to inspect my FWF at every oil change. Sort of a "50 hour inspection". Always looking for just what you found.

I think it's a good idea that people are turning their fuel pumps on and leak checking the fuel system on a regular basis.
 
Pierre??

I have to ask, did an adel /heat shield turn or something break? How would that contact/droop not have come up on earlier inspections? Is there a material quality issue too for it to be that charred or is it just the way fire sleeve works? Dont know just aking.

Glad you found it for sure. Good job taking the time to re-inspect all. Hopefully this thread will push many others to take the time to pull cowls and have a good hard look see.
 
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I was just thinking about this the other day!

I change oil at 30 hrs, with a spin-on oil filter. I ALWAYS use that time for a 30-hr FWF inspection. 1) baffles 2) exhaust pipes 3) alternator bracket and belt, 4) cable end brackets on throttle, mixture, prop governor, 5) fuel lines, 6) oil lines, 7) sensor leads, 8) mags and spark plug leads, 9) fluid leaks.

What I was thinking about the other day is, is 30 hrs frequent enough? It works out to about 3 times a year.

Glad you caught it. Curious what changed/moved/broke to create the condition. Wondering if a mechanic that installed the hose in December just mounted it too close?
 
scsmith said:
I change oil at 30 hrs, with a spin-on oil filter. I ALWAYS use that time for a 30-hr FWF inspection. 1) baffles 2) exhaust pipes 3) alternator bracket and belt, 4) cable end brackets on throttle, mixture, prop governor, 5) fuel lines, 6) oil lines, 7) sensor leads, 8) mags and spark plug leads, 9) fluid leaks.
Click to expand...

I would add
10) clean

Inspection are made easier and issues can be identified quickly if you keep the engine as clean as possible so I wipe it down at oil changes. Nothing to anal, just get the big chunks cleaned. I already have the rags out to clean up my oil spills which most likely happen when I trip over the drain bucket.
 
Pierre,

GREAT job finding that problem and not becoming a complacent statistic. Just as every accident has a chain of events leading up to it, your aversion has a chain as well. Think about it...

Doug Reeves creates a web site

You frequent the website

Ted does a great job with his incident and then posts it for all to learn from...KUDOS TED!!! Its rare to see an immediate save after such an unfortunate incident. I hope Ted is proud of himself for helping our entire VAF family.

Moral of the story is we should all communicate our mistakes as well as our successes.

So Pierre, I suppose you should send Ted a case of beer and double up on your VAF yearly donation. :D:D:D
 
Stephen, the FWF advice is an issue being worked by the RV Safety Committee. FWF work is not a place to go cheap or use bubba techniques.
 
The newer revision of the RV-10 FWF plans has that hose routed further away from the exhaust, with a 90 degree fitting on the end of the hose going into the fuel servo. I wonder if that's why.

-Rob
 
As an IA I work on all kinds of planes and I have seen a lot of scary stuff! People (not just RVers) are always asking me if there could be a way to do oil changes without removing the cowling or at least just removing the top cowling. A lot of plane's cowlings are a huge pain to remove and install. I always tell them I won't change their oil unless I remove the entire cowling because of all the stuff I've found over the years during a simple oil change. I think a lot of people just don't realize what a violent environment there is inside an engine cowling. Cold air, hot air, electricity, fuel, oil, paint, plastic, rubber, steel, aluminum, copper, brass, etc. all being heated, cooled, shaken, and vibrated to death. It causes all kinds of issues. Some of the crazy things I've seen are broken exhaust systems, carbs with loose bowl screws, broken air boxes laying in the bottom of the cowling, cracked cylinders, the spring steel wire inside scat hoses that has cut deep into engine mount tubes, exhaust pipes, hoses, and wires. It doesn't matter how new the airplane is. I've worked on brand new planes right out of the factories with less than 50 hours on them and found these things.
 
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Pierre's fuel hose--

Just talked at length with Pierre about his fuel hose. Thank goodness for firesleeve and teflon hose. There is no doubt in my mind that a "rubber lined" hose -----we all know what I'm talking about---would have come apart and sprayed fuel on a hot exhaust. WE are going to inspect this hose this weekend. Looks like a clamp or bracket may have failed that allowed the hose to lay on the exhaust. Doesnt matter what you build hoses out of, if they rub on something, or are near exhaust heat, or are too long or too short, failures can occur. Using good materials does help. Even firesleeve is not impervious to rubbing. Its great for heat, but not laying on an exhaust with movement

Personal note: I firesleeve ALL of my FWF hoses, dispite popular belief that only fuel hoses are needed to be sleeved. I do it because of the fire AND potential heat damage that hoses can get. Any hose, if close enough to heat can fail.

WE care going to post pics of the hose after we section it this weekend for all to see.
Tom
 
I've worked on brand new planes right out of the factories with less than 50 hours on them and found these things.
Click to expand...

Right on. If it weren't for field mechanics constantly finding and correcting this stuff, the GA fleet would experience a lot more mayhem. I hate to say it, but if you work on the certified piston fleet you see this constantly. So much that you really hardly think twice about it. It's only the real doozies or "who'd a thunk?" ones get notice. Most of the time you just grab a tool & some hardware, stick some Beemans gum on it & keep going. A lot of this is caused by poor engineering coupled with inadequate maintenance procedures/execution.
 
Cleaning is required at the 100 hour inspection.

plehrke said:
I would add
10) clean

Inspection are made easier and issues can be identified quickly if you keep the engine as clean as possible so I wipe it down at oil changes. Nothing to anal, just get the big chunks cleaned. I already have the rags out to clean up my oil spills which most likely happen when I trip over the drain bucket.
Click to expand...

If your operating limitations specify you are to inpsect per appendix D part 43 you are required to clean the aircraft and engine. I do this after I have inspected everything.

Glad to see your perseverence kept this from being an incident. Good catch Pierre and reminder.
 
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I am so glad the safety threads have taken off...

Since being a lurker starting in 2004 I have always wondered why so few tell the close calls/bad decision stories. I have only had a few minor ones so far in the past 2 1/2 yrs of flying. No cross country over 4 hrs round trip yet. So please guys, post anything you might feel may help us new pilots/builders.

Ted(an hour away and hangared next door) has helped me so much saving many hours of research/gotchas while building our RV-10. I am sure he has assisted in the removal of hundreds of cowls and tunnel covers these last few days. He is a fine man!!

Pierre, good job. Possibly the fuel "coolant" kept it from melting the teflon and relatively low pressures for such a quality hose.
 
Someone is watching over you, Pierre.

Pulling up that bucket, or whatever you sat on for a look see, was a very good move.
 
Good find

As a mechanic, I see all kinds of stuff. I tell clients that I can't fix it unless I find it. Can't find it unless I look, ( feel, grab, shake, tug, listen, smell....) and can't see it unless it's clean. One good find is all it takes to make a believer.
 
Sam Buchanan said:
Must be done at every oil change.....
Click to expand...

Absolutely, and every time you pull the cowl off. Take a good look at every thing, then look again. Get a good flash light and slowly look at every inch. If you cannot find anything .... look again. Then call a good builder buddy overand have them look.


Back in my ultra-light days I started a local "Buddy Program" where we would have a buddy look our plane over as no annuals were required. While he was looking at your plane you were inspecting his or hers. You could spend days going over every detail and your buddy would walk up and find something to improve in minutes. Many times IMHO several in flight emergencies were averted by these cross inspections.

Glad you caught it Pierre, thanks for posting.
 
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Good catch Pierre, thank goodness you found this.

As a habit, every time my cowling is off I wipe down all of my FWF which gives me the opportunity to inspect. I tug on wires, check harnesses, check fittings and nuts for tightness, look for any leaks and signs of something different from the last time. You get to know your FWF pretty well after doing this a few times. By wiping down, it keeps things clean and forces me to look and touch in a systematic way.
 
Good morning!

It's a great day to be alive:)

The inferno that would have been wasn't! Remember, I run around 25 psi on that line, supplying the fuel. I also take friends along...the reason for the -10.

Honestly, the line was installed incorrectly and has probably been that way since day one....it was missed during my oil change inspection because it's kinda hidden from view. You have to kinda contort yourself to see in there.

There is a 90? fitting on the fuel controller as well.

I'm a firm believer in Providence and the alternator failure was a prompt to remove the cowls. It has been repaired....a broken wire to one of the brushes...$33.37....not too shabby:)

God bless,
 
Pierre-a great safety lesson for all--

It doesnt matter how many hours you have flying, whether you have been working on planes for decades, or supply parts or pieces, stuff can happen. We all do everything in our power to make safe products. Sometimes, it is out of our hands, and the safety aspect is in HIS. Parts can fail (anyone lost an alternator lately), but good visual inpsections at regular intervals can stop most would-be accidents before they happen.
A great lesson for all of us---builders, pilots suppliers, to be diligent about safety. I hope everyone will take Pierre's, and Ted's stories and think about them before you take off the next time. Ted did a fantastic job in his situation. Just as commendable, Pierre did too. There are things that we can learn from both. Me too.
Tom
 
I am grateful to all those who post their "situations" so we all may learn.... and live. Over the years on VAF we all have seen many builders and pilots put their pride and egos in neutral and post them for all to see, scrutinize, debate, and most importantly...learn from. No one can learn it all, no one is perfect. We are all "practicing" aviators... as such we do the best we can. VAF is fortunate to have an atmosphere where this kind of information is shared, exchanged, and posted so others years from now can search and learn.

Thanks Mods for keeping this place a learning and open forum for experimental aircraft.

Thanks DR ........... I think I will make another donation to VAF......
 
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This is not a comment about Pierre since I do not know his background.

However, there are plenty of RV pilots and builders who are not engine/FWF experts (I am not an expert).

If you are not, have a competent person inspect your engine compartment. For builders this should happen before construction in the choice of fuel/oil lines. Quality counts.

Since I have to have an A&P perform my condition inspection, I get another set of eyes on my plane. While he does find nits, his attitude is concentrate on the items that can kill me. Control systems and FWF are two such areas.

RV buyers should consider a very detailed examination of FWF and control systems during the pre-purchase period or at least when they get the plane home. This may mean replacing and/or rerouting critical hoses, adding fire sleeve, etc.
 
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I am so happy for your alternator failure Pierre and consequently you finding this potential for a catastrophic failure. Also, many thanks for sharing it with us as stories such as this help our community to be safer.

Geico266 said:
I am grateful to all those who post their "situations" so we all may learn.... and live.
Click to expand...

This says it all for me? I have possibly learned more here then actually building my plane. Thru the last two years, reading stories such as this has prompted me to look at various parts of my plane, though nothing abnormal was found but it gives me a better feeling to have checked and verified.


Geico266 said:
Thanks DR ........... I think I will make another donation to VAF......
Click to expand...

I will do the same
 
Excellent information

Pierre,

This is fabulous information. Everybody has a chance to learn from the experiences of others. Look at the responses. I wonder how many cowls came off yesterday.

Everybody has a schedule they are comfortable with regarding cowl removal and inspection. For me, it is every oil change, 25 hours or before any major trip, or ANY time frame, regardless of hours, if the plane hasn't been flown for more than 7 days.

When I do my oil changes, I have my neighbor help me take the cowl off. While he is there I have him do a FWF inspection. I leave for a few minutes so he can to it without distraction. He has caught a couple of minor issues. We all get tunnel vision when looking at our own work!!!

Just some thoughts. Great information Pierre!!!
 
Something else to remember during inspections is to put a wrench on everything. Looking is good but I try to put a wrench on every nut, bolt, clamp I can touch. I find loose jam nuts on control rod ends, 'B' nuts, exhaust hardware, auto pilot linkages, jam nuts on rudder and elevator hinges, etc. almost every day. They may look and feel tight by hand but please put a wrench on them...it may scare you!!!
 
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The rest of the story.

Tom (TS Flightlines) on here, made a new line yesterday afternoon and overnighted it to me UPS...talk about fast service! It's a work of art and now mounted,....buut, I flipped it end for end and put the 90º fitting at the fuel servo and the straight end to the fuel pump, opposite the way it was. Now the fuel line is tucked in close to the FAB and 6" away from the exhaust, routed under the motor mount lower crossbar and straight up to the fuel pump....neat and not rubbing, touching or getting burnt!! again!!:D BTW, experimenters like us can do this legally and not need permission!

Tom's braided hoses will only take so tight a bend, then resist and this is what made it curve toward the exhaust. Off to get a crows-foot and torque/torque seal.:) I'll see Tom at Ridgeland this weekend and he'll cut the hose and show pictures early next week.

All's well that ends well,
 
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Sometimes even apparently smooth surface contact can be a problem

Strive for no contact with the various lines. This is a piece cut out of my fuel pressure line which was innocent looking near the firewall adjacent to a spiral sleeved engine control cable (I forget which one it may have been the carb heat). There was no visible evidence of a problem but as I was checkint the area I felt fluid (fuel) on the back side of the tube. In 600+ hours it had worn through and had started leaking directly above the right side exhaust pipe.

Bob Axsom

IMG_4283.jpg
 
pierre smith said:
I flipped it end for end and put the 90? fitting at the fuel servo and the straight end to the fuel pump, opposite the way it was. Now the fuel line is tucked in close to the FAB and 6" away from the exhaust, routed under the motor mount lower crossbar and straight up to the fuel pump.
Click to expand...

This is exactly how the new revision of the plans shows it. I'll try to get a scan of it tonight and post here. Seems to be a really important point, given your experience. Glad it ended well!

-Rob
 
I would add...

We all have hangar buddies, especially when they are builders, to grab them while things are apart just to get another set of eyes. Amazing how that usually uncovers something we missed. That goes both ways, btw... I've a friend who is an AP/IA helio mechanic for Columbia and always like to have him snooping around. I love it when he says: Why'd ya do it this way??

Too bad he's building a plastic airplane tho... Sorry Brian...


.
 
Lan - if it were me, I'd feel a LOT more comfortable if there was at least a heat shield strapped to the exhaust where the fuel line comes close. If there was another way to route the line, I'd feel a lot better.

Paul
 
I'm with Paul on this one.

I don't feel comfortable with less than 1 1/2" between a line and the exhaust.

Congratulations for your wisdom in removing the cowl!:) This is one of the big benefits of this forum.

Best,
 
Lan-

My .02 cents----find a way to reroute this hose, or secure it higher away from the exhaust, and put some shielding on the exhaust pipes. Even firesleeve can break down after being subjected to repeated heating. I hope you are using teflon hose. Even so, it doesnt take much heat to distort, or break down the liner of ANY hose that is very near exhaust.
Tom
 
TS Flightlines said:
Looks like a clamp or bracket may have failed that allowed the hose to lay on the exhaust.
Click to expand...

I was under the impression -- most of which I learned here on VAF -- that fuel line hoses should not be clamped. But I looked at a respected builder's project last Saturday and, sure enough, he had clamped the fuel line to the engine mount.

Can someone tell me when/where/how clamping fuel lines is acceptable and when it's not?
 
Bob Collins said:
Can someone tell me when/where/how clamping fuel lines is acceptable and when it's not?
Click to expand...

Clamping fuel lines is OK Bob, so long as you leave the part that actually goes in to the engine with "slack" (for want of a better term) adequate for the fact that the engine moves around - primarily it rotates in the mount when cranking and shutting down. So if you clamp the fuel line to the mount, you need to leave the part that goes in to the fuel pump with some slop for engine movement.

BTW, I am intrigued by the idea for FWF book - the problem, of course, is that if you want a "step by step" approach, then it will only be for one EXACT configuration, using EXACTLY the kit parts (ala the RV-12). Most folks do a bit of their own thing somewhere FWF, so it becomes problematic. I would ask folks if they have a dog-eared copy of Bingellis' "Firewall Forward" with oil stains on it - a great primer on the topic!

Paul
 
pierre smith said:
I don't feel comfortable with less than 1 1/2" between a line and the exhaust.
Click to expand...

Pierre,

I agree with this, but it is tough if you have an IO-360 with horizontal induction. There is pretty much only one route for the fuel line, and the clearance is tight everywhere. I used copious heat shields and managed to maintain a little over 1" of spacing between the hose and the heat shields (so, a little more than an inch between the hose and the pipe) but it is tricky.

20080517_fuel_hose2.jpg
20080517_fuel_hose1.jpg

20080517_fuel_hose3.jpg


But if I had as much clearance on my engine as you can get on yours, I'd use it all! :)

mcb
 
Used the Pierre "bucket approach" yesterday

On my RV9 . Its only carb 0-320 but I pulled the cowl, leaked checked the fuel system , checked the B nuts on the pump. and finished up installing some ceramic Hot rod exhaust manifold wrap onto a section of exhaust within 6 inches of the fuel line. I had used that wrap for many years on a Long EZ to help cool the underside of 0 235 up draft cooling. It made a lot of difference on the CHT for that Long EZ. Can't hurt in keeping the general area a bit cooler on the RV9. At the end of the day put it all back together again and made a 45 minute flight.
 
I don't feel comfortable with less than 1 1/2" between a line and the exhaust.
Click to expand...
I agree with this, but it is tough if you have an IO-360 with horizontal induction. There is pretty much only one route for the fuel line, and the clearance is tight everywhere.
Click to expand...

You can easily have 6-8 inches of clearance. Use a right-angle pump fitting (which also allows an easy pressure tap) and a straight end hose, then run up and forward over the left lower mount ear, then along the sump seam to the front. Adel the fuel line to the sump bolts.

2zgx7jr.jpg
 
DanH said:
You can easily have 6-8 inches of clearance. Use a right-angle pump fitting (which also allows an easy pressure tap) and a straight end hose, then run up and forward over the left lower mount ear, then along the sump seam to the front. Adel the fuel line to the sump bolts.
Click to expand...

Dan - thanks, but how did you get the fuel hose around the mixture bellcrank and related hardware? On my engine there isn't any room there.

mcb
 
Didn't use a mixture bellcrank on this IO-390 (AFP) or a previous IO-360 (Bendix).
 
Heat shields help a lot.

mburch said:
Pierre,

I agree with this, but it is tough if you have an IO-360 with horizontal induction. There is pretty much only one route for the fuel line, and the clearance is tight everywhere. I used copious heat shields and managed to maintain a little over 1" of spacing between the hose and the heat shields (so, a little more than an inch between the hose and the pipe) but it is tricky.

mcb
Click to expand...


Yeah, heat shields allow a closer fit for sure. My problem was that the exhaust that burnt the fuel line had already become part of the collector, so I couldn't add a heat shield anyway. With a 90 degree fitting on the fuel servo, my fuel line is now 5" or more from the nearest exhaust pipe:)

Best,
 
More than one way to skin a cat

mburch said:
Pierre,

I agree with this, but it is tough if you have an IO-360 with horizontal induction. There is pretty much only one route for the fuel line, and the clearance is tight everywhere. I used copious heat shields and managed to maintain a little over 1" of spacing between the hose and the heat shields (so, a little more than an inch between the hose and the pipe) but it is tricky.
Click to expand...


Or, if you use stainless steel hardline, you can really stuff it up out of the way. I have plenty of clearance.

28ric6p.jpg



etzdzo.jpg
 
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