Fuel line stand-off

455 Bravo Uniform

455 Bravo Uniform

Final Approach
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455 Bravo Uniform
The black braided line is fuel. It was contacting the spark plug wire bundle and looked to be wearing the wire insulation. Is this a possible fix? I’ve heard it’s a no-no to connect fuel lines to wiring.

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455 Bravo Uniform said:
The black braided line is fuel. It was contacting the spark plug wire bundle and looked to be wearing the wire insulation. Is this a possible fix? I’ve heard it’s a no-no to connect fuel lines to wiring.

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Surprised no one has commented so far? Looks like a slick use of a zip tie and rubber hose. My hats off to you for ingenuity.

I don't like using zip ties on our planes or on anything long term. I would suggest using a rubber lined adel clamp bolted on instead.
 
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Gary Ward said:
Looks like a slick use of a zip tie and rubber hose. My hats off to you for ingenuity.
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Us experimental guys have been using that trick for a long time.

Don't know how they do it for certified planes but I was taught to keep fuel and fire separated by at least six inches and never place fuel above fire. FWIW I like as much separation as I can get so what was done here would not be acceptable to me.

AC No: 43.13-1B gives information to answer these type of questions. In there I read:
"In no case should wiring be supported by the fuel line."

Download a copy here:

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf
 
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Would prefer to see Adel clamps. I don't care how tight you pull your zip ties, they chafe into whatever they touch at some point. Consequently, if you have zip ties on any portion of your engine mount go cut them off before your next flight and replace them with Adel clamps. The number of engine mounts I've seen needing repair or replacement because of zip ties.....
 
Der Fliegermeister said:
Would prefer to see Adel clamps. I don't care how tight you pull your zip ties, they chafe into whatever they touch at some point. Consequently, if you have zip ties on any portion of your engine mount go cut them off before your next flight and replace them with Adel clamps. The number of engine mounts I've seen needing repair or replacement because of zip ties.....
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I agree, I removed several from my mount when I replaced the engine last year.
 
Fuel and electrical never touch in the military....We try to not even share bolts when clamps are butterflied to separate them.
 
Der Fliegermeister said:
Would prefer to see Adel clamps. I don't care how tight you pull your zip ties, they chafe into whatever they touch at some point. Consequently, if you have zip ties on any portion of your engine mount go cut them off before your next flight and replace them with Adel clamps. The number of engine mounts I've seen needing repair or replacement because of zip ties.....
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wrapping some electrical tape around the engine mount before you install the ty rap helps out a lot
 
AKBill said:
wrapping some electrical tape around the engine mount before you install the ty rap helps out a lot
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For a bit, but how do you inspect the mount under the tape? Cut it off every annual and reapply? Zip ties will eat through electrical tape too.

And for all you obedient earthlings: you ARE using an approved zip tie whenever you use one, right? o_O
 
Der Fliegermeister said:
For a bit, but how do you inspect the mount under the tape? Cut it off every annual and reapply? Zip ties will eat through electrical tape too.

And for all you obedient earthlings: you ARE using an approved zip tie whenever you use one, right? o_O
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Do you remove the adel clamps to inspect under the cushion every annual? o_O
 
Daleandee said:
AC No: 43.13-1B gives information to answer these type of questions. In there I read:
"In no case should wiring be supported by the fuel line."
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But what about wiring supporting a fuel line, as in the OP’s case? ;)
Der Fliegermeister said:
And for all you obedient earthlings: you ARE using an approved zip tie whenever you use one, right? o_O
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use the 9-g Part 135-approved baggage tie-down tie wraps.
 
Koroseal Lacing Cord ( black plastic shoe stringy stuff) was very common in the

past.

I have wondered if it would chew things similar to zip-times.

Are there different types of zip-ties that are cushioned?
 
To be clear - that pic is sideways. The plug wires are bundled and on standoffs with clamps. They run topside of the #2&4 cylinders. The fuel line comes thru the rear baffle at Cyl #2, then goes to the “spider”. The fuel line is unsupported and has started to sag to where it sits on top of the plug wire bundle. I noticed it and looked under and the fuel line is wearing the plug wire insulation. This was my stop-gap for the next 5-6 hours of tach-time to get to OSH & back.
 
My ride had all kinds of stuff zip tied to the motor mounts - I didn't get real excited since it seemed unlikely that they were wearing through the metal tubing since they were not wearing through the paint. I have since pretty much replaced all of them with cushioned Adel clamps on general principals, but I suspect that the zip ties could have lasted quite a bit longer.


Magman said:
Are there different types of zip-ties that are cushioned?
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https://griplockties.com/ - but this is a pretty new product.
 
There are 2 screws holding that wire holder. I’d make an aluminum support from scrap that attached there and held the fuel line. Pretty simple.

where do you have a 6-wire bundle like that? My fuel lines are low in the cowl and mags are high. That pic isn’t normal for my eye.
 
And for you zip tie nazis? I love zip toes. I have aviation nylon, stainless steel, and cheapo NAPA zip ties in abundance. For my airplanes? I prefer GripLock Ties. Rubber backed. Reusable. Good product!

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I don’t think either of those are supporting the other, that just a way to keep them from chafing each other. If accurate, I don’t see a problem with it.
 
JAWS said:
Do you remove the adel clamps to inspect under the cushion every annual? o_O
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If I found that clamp moveable on the mount I'd take a look under it and maybe do something about fixing it.

The problem with nylon ties eating the mount tubing is that dust or sand gets blown into the cowling, even just tied down outside, and gets under that tie. It gets embedded in the tie, and if that tie moves it acts like sandpaper and cuts away at the metal. You're allowed no more than a 10% reduction in the wall thickness of the tubing, and in a mount that has .035" wall, that's .0035", or about the thickness of a sheet of printer paper. I had to remove several mounts that had the imprint of the tie's zip teeth ground right into the tubing. A loose Adel clamp can do the same thing.

In the 1970s I spent some time in a truck parts wholesale outfit. Nylon air brake tubing came out around 1971, and was enthusiastically adopted as a good replacement for the copper tubing commonly used in those systems. One trucker took me outside and showed me the frame on his logging truck; a 1/2" nylon line had cut a half-inch into the top flange of that strong steel frame rail. Dust and grit from the roads embedded in the tubing and ate the rail as the tubing vibrated. Very expensive damage.
 
Stewartb said:
where do you have a 6-wire bundle like that? My fuel lines are low in the cowl and mags are high. That pic isn’t normal for my eye.
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By memory, since cowl is on now, 3 wires from left mag, 3 wires from right mag, bundled going to the left bank of 3 cylinders.
 
JAWS said:
I don't, as long as they are the proper size and are tight. As Dan stated, a loose adel clamp is just as bad as ty-wraps. Those get replaced. I like the WH series, white cushion. A bit easier to fit than the WDG style.
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Yeah the WDG can be a real turd when they're new. Pair of fluting pliers helps to form the flat end a bit to allow a bolt or screw to be sent through. If possible, I loosen the clamp and slide it far enough to inspect beneath it, then slide it back and tighten it. Many times I find that it needed repositioning anyway to keep something off of something else.
 
The way the GripLock ties have the rubber around the circumference of the tie looks like it might collect dust and grit in the slot. They closed off the female end, but closing off all of it would mean filling the central channel.
 
The best response to fear of the unknown is familiarity. Try them before you knock them. Great product. I don’t have any fear of standard aviation zip ties on my engine mount because it’s easy to move them a little. If mine leave wear tracks in the powder coat I’ll do something to address it but adel clamps aren’t the automatic answer.

My Cub’s DAR didn’t take exception to zip ties on my engine mount. To the contrary, he wanted me to add a few to limit movement of some wires. He preferred the standard standoff with a zip tie choking another zip tie.
 
Assuming this is a production airplane, I am rather certain it was not rigged like that when it left the factory.
 
JAWS said:
I don't, as long as they are the proper size and are tight. As Dan stated, a loose adel clamp is just as bad as ty-wraps. Those get replaced. I like the WH series, white cushion. A bit easier to fit than the WDG style.
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Do you find that the WH tend to absorb oil? Odd question I know, but I've removed a lot of the WH clamps because they just don't seem to last as long as the WDG. I will give you that they're easier to install because the metal is thinner.
 
Stewartb said:
The best response to fear of the unknown is familiarity. Try them before you knock them. Great product. I don’t have any fear of standard aviation zip ties on my engine mount because it’s easy to move them a little. If mine leave wear tracks in the powder coat I’ll do something to address it but adel clamps aren’t the automatic answer.
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It works for you because you're familiar with what's inside the cowling and you're checking things. The usual owners (which is most of them) don't have that advantage, and if their mechanics do this sort of stuff it can cost a lot of money later on.
 
Timbeck2 said:
Do you find that the WH tend to absorb oil? Odd question I know, but I've removed a lot of the WH clamps because they just don't seem to last as long as the WDG. I will give you that they're easier to install because the metal is thinner.
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I work on mostly turbines. They seem to have a variety of different clamps, though most are the WH series. Yes, they will swell if contaminated with standing oil, but there shouldn't be oil everywhere on a plane, should there? o_O

WH series metal is stainless steel vs aluminum for WDG. Also withstands higher heat. Different clamps for different purposes. Koroseal is still a good product too and is used in places.

Best tool to help install adel clamps is an old hacksaw blade with a sharp groove ground into the end. Used to secure the screw until nut and washer is installed.
 
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