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Why did this fuel line produce debris?

Ed Cesnalis

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The problematic hose has been Gates Barricade Fuel Injection hose. This hose has 5 layers:

  1. Tube
  5. COVER



This line produced debris because it does not have a smooth inner wall. In the photo you can see the reinforcement layer when you look at the inner wall of the tube. The cross hatching isn't visible through 3 layers what shows is a rough texture. The opening is not a circle but instead a circle with a bunch of steps created by the strands in the mesh layer. When this bumpy inner walled fuel line is inserted over a barbed fittings the bumps are shaved off resulting in rubber debris contamination.




The hose below had been in service for 11 months and removed to check its condition. Smooth inner wall hose like this does not have the reinforcement / mesh layer showing through the inner wall and a barbed fitting isn't likely to shave it smooth.

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Hi Ed,


I don't think the fuel injected hose you got from CPS was Gates fuel injected Barricade hose. I think it was another type. If I remember right that some of the hose that old CPS had was made in the US and China.


Here's a photo of the hose I got from CPS. It has "Gates Fuel Injection ... Barricade" printed right on the hose.



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Hi Doug,


I'm not 100% sure, but I don't think what ED has in his picture is what the old CPS used to sell. I don't think the old CPS sold the Gates Barricade hose. That said the old CPS hose was the problem child as far as trying to force it over the barbs on the CT, but both the old and new CPS were trying to use fuel injection hose. I quit using that a long time ago. It just has no flex when sliding it over the fittings. The other thing people can do is lube the fitting and or hose end so it slides over the fitting and doesn't dry scrape the hose liner. Drink a lot of water before the hose change because a little saliva can go a longs ways. <_<





Absolutely no silicone of any type on the hoses. It is not compatible with fuel or oil.

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I asked gates about the rough texture on the inside of their hose, because when that texture is apparent it is very easy to cause damage with a barbed fitting.




As you mentioned, our fuel line hose is designed with a spiral textile reinforcement to help provide resistance against internal pressures. The visible amount of “texture” may vary between hose types, ID’s, and manufacturing runs, but still be within specification and not affect the performance.


Regarding ROTAX, please see the attached Alert Service Bulletin dated May 31, 2012. Since Gates does not support aviation applications, I would suggest that any Barricade hose be replaced. BRP/ROTAX should provide any further direction.


Hope this information helps.





If visible texture results in likely damage but does not result in the hose being out of spec then it would explain the hose getting a clean bill of health while it still causes us grief. Variance between manufacturing runs could explain intermittent results.


Look at the reason for the Service Bulletin:


1.3) Reason: Due to variations in manufacturing of the fuel hose, rubber particles may become detatched.


Read that reason carefully, Rotax came to the same conclusion that I did.

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Hi Ed,


Just an FYI from some one up in the higherarchy


One humorous side note; the hose that Rotax had all the problems with in the new corona pump (ASB-912-061) was Gates Barricade greenshield! It was a batch problem though, the hose is good. The really funny part is the problem hose was marked “made in USA” the replacement hose is the same but made in Mexico, go figure..

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...the hose that Rotax had all the problems with in the new corona pump (ASB-912-061) was Gates Barricade greenshield! It was a batch problem though, the hose is good...


That is the whole point, the hose is good, but there is/are batch problems/variances [texture] that results in rubber particles becoming detached [shaved off]

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Hi Ed,


Bottom line is nothing we can do about it, but use due diligence as an owner and mechanic. It can be any hose on the market that any body supply's. Nobody is immune. It isn't this answer that many want to hear, but it is all we have to work with in reality That's why it does pay at times to shop for parts and even more important at time the mechanics knowledge of that particular subject.

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Hi Ed,


Bottom line is nothing we can do about it, but use due diligence as an owner and mechanic. It can be any hose on the market that any body supply's. Nobody is immune. It isn't this answer that many want to hear, but it is all we have to work with in reality That's why it does pay at times to shop for parts and even more important at time the mechanics knowledge of that particular subject.


I could not disagree more Roger. Virtually every one of us received a new CT free of rubber debris in our fuel systems. A demonstration that the contamination is unnecessary. Tom Baker uses OEM hose and no problem there (one small exception at the fuel pump, and admittedly a small sample)


Lockwood has gone to Tecnam's OEM hose, it has a smooth substantial inner-wall. This change completely eliminated the rubber debris issue that they experienced when they used Gates hose. I just skimmed these threads again and there is a truly alarming number of incidents reported, the common factor being gates hose, barricade and not, fuel injected and not. Gates hose from CPS or from NAPA both result in damage if I insert a barbed stem. Gates admits there is variance in their inner wall (the part that gets damaged.)


Roger there are 2 things we can do about it.

  1. Use OEM or other proven fuel lines - Stop using, marketing and selling Gates hose for CT fuel line replacement, it isn't OEM, it isn't equivalent, its inner wall varies.
  2. Use appropriate beaded stems with flat landings - there is no good reason to apply sharp cutting edges to the inside of our rubber fuel lines.

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Hi Ed,


"Use OEM or other proven fuel lines", these aren't proven because that have not been installed in any application and run. Just because Tom has used hose from one supplier does not keep him from ever having debris. Hundreds have used all types of hose and never had debris either. It's just a feel good thing. Plus who do you think Rotax uses for their OEM hose? Gates

Is OEM hose some how immune from a bad batch? Who is the OEM brand and what happens when they switch brands? Is that OEM hose better? I just did a hose change and it had 3 different hoses on it from FD. Who's was the right one and which was OEM?


I think your not seeing the big picture. No matter who's hose in the world you use it can be bad and no matter who you buy it from. You could buy hose all day from FD or Rotax if they sold it and when you put it on the plane and run it, it can still produce debris if it's bad or a bad install. There is absolutely no way anyone could certify a hose as perfect off a roll or from any Mfg unless it was pre-run in an application and then it still would fall on the installer.


Rotax a bad batch right from the hose Mfg and that's why they had a recall on the bottom fuel pump hose. What you are saying is if I buy a lottery ticket I will win. There is no way you can get in your car today and everyday and say no one will ever in my lifetime hit me. You can't get in your car for your entire life and say my battery will always be good.


All you can do is buy hose from someone, use whatever fittings you want to use in the world and hope that your install was perfect. Are there hose choices better than others for different applications? Absolutely.


You best defense for all of this entire issue is after a carb sync is done to run the engine at 3500-4500 rpm on the ground for another 20-30 minutes. Pull each carb bowl and gascolator and look inside. Even with that is no 100% guarantee that the installer did cause a little spec to be loose somewhere and down the road 25 hrs that it doesn't break free.


When all the emotional issues are stripped away it still boils down to the owner and mechanic's education.

That's why Tom and many other mechanics aren't having issues. Why do you think myself and Rex have not had 75+ cases just like yours and why aren't all the others 75+ having the same issues. (pre-install education and a more sterile procedure) It comes down to a very select few which had been very unfortunate and I can feel for those that have their engine stutter in flight.

Yours by far was the worst I have seen or heard of. Even though your hose could have produced some debris the amount suggest it wasn't a good install.


There are no 100% guarantees and it isn't 100% preventable. You still have the human factor if you could possibly get passed a perfectly Mfg. hose.



Ask yourself this one question and you will see if your post will solve hose debris and bare up to absolute scrutiny.


If everyone switched fittings and everyone used hose from FD would you be willing to put up $1K for each person that reports debris in their hose lines in the US from now on?


If the answer is no you have your answer to your post as being the solution.

If yes, I'll help you get it as far as possible, but I think you should have thousands in the bank.


As many subjects as you and I have discussed over many years and come to very good problem resolving solutions I fear we will be apart on this one.

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Ed is right. If the fuel line was defective, someone needs to take responsiblilty. If the fuel line was an incorrect application, someone needs to take responsibility. If the fuel line was installed incorrectly, someone needs to take responsibility. If the fuel line replacement procedures were incorrect or nonexistant, someone needs to take responsibility. If there is less risk to do a 5 year condition inspection than a wholesale replacement, that should be changed too. Do you see a pattern here? I'll tell you what it is. Ed didn't do anything wrong. One or more other people did.


My opinion is this: First of all, the hose replacement should have been done on a condition inspection. If a condition inspection is good enough for Beech and Cessna, it's good enough for me. The old hoses that were removed from my aircraft were in good shape. Five years from now, on my airplane, it will be a condition inspection. If my A&P won't sign it off, I'll take the airplane to experimental. All of this could have been avoided with a condition inspection.


Has anyone addressed Ed's question about whether or not the Gates hose was a proper application? I don't recall seeing an authoritative reply.


Now on to the big question in my mind. Is there a replacement procedure for the hose? Specifically, is there clear instructions that the hose must be flushed, blown or otherwise cleaned after the fittings are installed? That this must be done is common knowledge amongst the certified and experimental people. If it were done and it was obvious that the hose was shedding chunks of rubber, it would be a giant red flag.

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Not touching culpability for Ed's hose issues but Rotax isn't alone in the rubber replacement service.


If a condition inspection is good enough for Beech and Cessna, it's good enough for me.


If those Beech, Cessna (or anyone else) are powered by a Lycoming then they have a similar replacement service. The latest maintenance manual is a bit more stringent than Rotax:

As airplanes and engines attain age, there appears to be a need to reemphasize the inspection or replacement of engine hoses or lines carrying fuel, oil or hydraulic fluid. The hose manufacturers definitely recommend regular inspection and replacement of all such hoses at engine overhaul even though they look good. Age limit of rubber-steel or fiber-banded hose has generally been established at four years. This limit of four years is generally considered to be “shelf” life.





Lycoming Service Bulletin No. 509 must also be complied with if rubber hose is used to carry low-lead aviation gasoline. Aeroquip, the manufacturer of hose used by Lycoming, has recorded several failures of 601-type rubber hose. Although it is satisfactory for other purposes, this hose appears to be adversely affected by low-lead aviation gasoline. 601-type rubber hose used for low-lead aviation gasoline is to be replaced after no more than two years of use. Aeroquip and Lycoming recommend that rubber hose be replaced with Teflon hose

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I agree with Dave, hose change are throughout the industry.


You should never fear what you know, but be fearful of what you don't know! There is always more to learn that what we know. As the old saying from X-Files TV show used to be, "The truth is out there".


Ed did nothing wrong in the physical sense, but could have learned about this prior to doing it. What he and especially the mechanic did was fail to get educated before the procedure. Ed, no disrespect as we are friends, but we all fall in this boat many more times than all of us should in our lives. We trust someone else to know more. Ed trusted his mechanic knew everything there was to know about what he had to work with and the proper technique. Even if we trust our mechanics and doctors it does not relive us of our responsibility to educate ourselves. There are no schools for hose replacement and no specific manual that tells you how to do it. Just like some have said here, if they publish an SB, they will say it isn't binding and I'm going to do it my way. It hasn't any teeth and isn't legally binding as several have pointed out here. If they make all the parts, time limits and a specific procedures mandatory in an SD how many will complain? My guess is the same ones that already complain about doing it now, but then it will have legal teeth. The responsible party for the actual procedure is the mechanic and that again was lack of education prior to the procedure. No matter what maint. procedure is done on a plane regardless if it was hose it carries a risk and some more than others. So if any procedure can cause an issue why do maint. at all? Would you tell all the Doctors, not to operate and possibly improve or save a life because we all know surgeries no matter how minor carry risk? That's a bigger risk than a hose change. Do you expect that doctor to be educated as much as possible before that procedure? Are you expected to know or do you know as much as the doctor?

Why are you expecting anything less of ourselves and your mechanic.

Read this post listed here. One of our own found problems with the hose that only removal would have found and no condition inspection and just looking at it would have found. When it comes to flight safety and hidden damage that can not be found by a condition inspection that is only a false sense of security. Many hose issues can not be seen so how can they all be on condition? I find hose issues all the time when I do hose changes. After 35+ changes I know there are hidden issues at 5 years that no condition inspection could ever find from just a look see with a flashlight or a hose squeeze.




You would think mechanics would know about how to properly change hose, but do you really know he read up on procedures or do you know he followed those procedures. There is no hose change school or specific hose change documentation that I know of any where that came from a legal specific source except maybe an individual that wrote something up. Now let's say a school that specifically address your concerns gets put in place, how many of the guys here will still say don't fix it if it ain't broke or you can't make me go to that school or says it's too expensive I don't want to go to school or the guy who says I've been changing hose before you were born sonny.

Cessna has a mandatory hose change on it's turbo engines, but it's mandatory and not just an SB.

No LSA Mfg needs or will take responsibility for how hose is installed and the exact (spell it out for me procedure) because of liability and it would be legally foolish for them to do so. Rotax tried to make peiople attend classes to learn such things along with many other items, but how many said you can't make me go and didn't?


In our LSA industry there is not and was no specific hose or improper use of hose, just poor judgment, lack of education and poor isntallation. You need to ask, Why did Ed's plane have these issues with this hose when hundreds did not with the same hose and barbed or no barb fittings? Many still use FI hose without any issues. This was not a hose failure it was an install failure which could have worked with the proper precautions. Who took the time to learn about those precautions?


I fail to see why every one wants to blame someone? If you go to court a lot it seems to be the American way at times. We need to take responsibility for our own actions or lack of action and many times it's only a matter of education to stave off probelms we encounter.


This info for the hose change and selecting proper hose for your specific application and seeking education on proper installation is not hidden or hard to find and is everywhere on the web. You just have to make the effort. Ed just recently did research to get the education and found all sorts of info and I bet his mechanic did not pre-educate before this procedure.

So now that Ed is educated do you think he could help his mechanic do a better job? Absolutely. So if this had taken place prior to this procedure it probably would never have happened.

So if you want to affix blame which I don't think there should be who gets the finger point?


I still may be the bad guy here for some of you, but the products were not the issue.

It could have been done without any problems with what they had on hand (there may have been a better choice) if someone had just taken time to read about the procedure at hand.



Refusing safety procedure out of fear is never the answer. Just do a better job a detailing and being better educated over the next guy.

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I'll make my reply nice and simple, Roger. I've owned my own company for 18 years. We design, build and ship electronics. We've made lots of mistakes in those 18 years. The vast majority of those mistakes are fixed long before a faulty product reaches a customer, because our employees are taught from day one that their first duty is to fix problems as soon as they are identified. My standard spiel is that it costs $2 to fix a problem in engineering, $20 dollars to fix it in production and $200 to fix it after the customer receives it. Nobody gets punished for identifying a mistake, whether it's their's or someone else's.


If a customer believes we shipped him a faulty product, we investigate immediately and we *fully* disclose what we know to the customer. If it's our fault we make it good. That might involve shipping good product overnight at our expense, giveing them a discount on their next order, or simply saying we're sorry and that we screwed up. Whatever makes it good. And then we make sure that the problem doesn't happen again. That usually involves training or better documentation. And we usually go back and tell the customer what we did to make sure it doesn't happen again.


Simple rules. At the very least, Ed, and all the other Rotax owners that are in a similar situation deserve to treated as fairly.


Finally, I really have to emphasize that there needs to be a written procedure to clear out any debris after a hose replacement. I wrote an email to John Gilmore two or three months ago advising him of this. He agreed, but I'm not sure there was any follow through. Your comments about researching turning up all kinds of information doesn't do Ed any good. Rotax has been selling 912's and Flight Design has been selling aircrafts for year and should have the common sense and corporate responsibility to give the maintenance people all the info they need to do a job properly.

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And if it wasn't your fault and they keep claiming it is, then what does your company do?

I know you have had these people, I know I did when I was in Mfg. Have you ever refused to fix something that someone else damaged and it wasn't your fault? I have fixed things when it wasn't my fault as an Mfg. , but that was out of good business sense and not a blanket policy. If you were the Gates CEO right now what would you tell one of us when we accused you of having bad hose and that is was your fault for letting us install it the way we did and you had to pay for all my repairs? You know as well as I do installers of your product or any others make mistakes through no fault of your own no matter what you tell them ahead of time.

I forgot to mention in the last post that no one in the our industry can dictate legally how to install something. That is always left to the installer. They might recommend, but that's it. They can dictate only what is to be installed i.e. if FD wanted to use only their hose. An SD can only be issued on flight safety issues and failing to install hose properly at the mechanics level is not an SD. If FD chose to pick one hose then that would limit them to only that hose for future use or risk making an entire fleet make the same change later on or they would have to stop production if their supplier was late on deliveries because they could not use another brand because of their own SD. Have you in your company ever had to buy a part from somewhere else? Did you ever have to completely change suppliers?


If you or your mechanic learns how to do something this year it does not stop the procedure from changing next year. So the company puts out a notice. Is it the companies fault if people don't keep up on continuing education or that you failed to check to see if last years procedures are still in place. Should they hunt down everyone in the world that might use their product or in this case hose. Has your company made changes to any equipment over the last 18 years and if they did did you go out and tell everyone from that 18 years you made a change and tell everyone from new what was different in all aspects 18 years ago?

Just like your company, it is up to the buyer to identify the need to buy your product, learn which product will suit his needs and learns how to install it the correct way.


At some point your buyers have a responsibility to research your product and make an educated decision on whether to buy and if they are smart ask for any specific instructions on the install. What if someone bought a lot of your equipment and installed it improperly and then said you were to blame and had to pay them for everything? You personally know it isn't your fault they just didn't use due diligence in the research, prep and install.


If Gates hose is not to be used on aircraft like ED said they stated, I know they did, then you'll have to quit using NGK spark plugs too. It's on the side of the box, no aircraft. Actually I can think of 5 items on our plane that the MFG says not to use on aircraft.


If you don't want to use Gates and let's say FD would go along with that then how will you force Rotax to stop using it and being on your engine? Does that mean FD has to strip all the Gates hose off the factory engine?

Then if an SB were put out does that mean FD and Rotax must do it only that way or it's illegal?


Bottom line many of these things aren't going to happen so to protect yourself, education is the key.


For Ed and the others to be fairly treated then like I have said all along they must prove that it was bad hose and they had no fault of their own involved. Ed has already said it was mechanical damage which is very easy to see from the pictures so that only shows the install was improper at this point. Who should treat them fairly? The mechanic, CPS, Gates, FD, Rotax or the people that made the fittings? No one made anyone use a certain brand of any thing. They could have selected anything they wanted.

If FD mandates a specific hose then heaven help them if a single person gets some debris for any reason. If it is the installer like it usually is then the finger point will still be aimed at FD and it could cost them big bucks or it will cost you big bucks trying to prove it was the hose and not the installer.



You can prevent all this heart ache with all of our maint. procedures by first identifying the procedure, researching the procedure, talking to someone who has done the procedure and actually taking continuing education classes. for the mechanic.


Let's take it another step after you have all the things you want. Now everyone is in a feel good place. Problem solved?

Your A&P has done everything that seems right to you and used FD specified hose or part. If it doesn't work out this time do you blame him because he would have known the proper procedure if he had gone to a Rotax class? If it was an FD maint. issue do you crucify him for not going to the FD sponsored classes or talking to them in advance? So where will this saga end, once you believe you have what you want? Until next time.


This can be debated until we all die and you can try to put safeguards in place and blame everyone else and you will never be protected until you learn and that's a constant ongoing process and that's what you did over the last 18 years.



There is way too many people across the US that are doing it right with what they, you and I have at hand with all types of aircraft. It is up to the few having the issues to catch up and do it right and not to shotgun approach the issue and make it a hardship for everyone else.

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