Which 5 year rubber part Replacement kit? Which Fuel Line?

[Ed Cesnalis]

How about . . . . "Not For Use With Those Types of Fittings?"

Seems like the hoses are fine, but they are getting chewed up by the installation and fittings.

 

Gates uses this disclaimer for the fittings "Beaded stems are recommended for rubber hose. Barbed stems are for use with plastic tubing only, due to the sharp ferrules and serrated teeth."

[Flying Bozo]

You guys are all stuck on the barb being the cause of the problems. Take a close look at the picture I posted on the bottom of page 6 and you will see the marks where the barb was in the rubber and then where the rubber that was undisturbed by the barbs was coming apart on it's own totally without being in touch with the barbs.

Larry

[Roger Lee]

There are two completely separate issues at play here.

Mechanical damage (by far the number one problem) and bad hose liner (actually fairly rare).

[Flying Bozo]

It looks like from the damage to the hose in my picture (on previous page) that I had both things going on at once!!

Larry

[Doug G.]

OK, let me sum up...Gates says, "Don't use this hose on these fittings." Rotax, CPS, and FD say, "Never mind what the manufacturer of the hose says, we supply it - use it anyway!" What is wrong with this picture from a safety standpoint! Or from a legal and ethical standpoint.

And Roger, please don't say that these statements are the mechanics fault - these statements have nothing at all to do with the mechanic, they are from the hose manufacturer, the engine manufacturer, the airplane manufacturer, and the reseller of the hose.

[Ed Cesnalis]

OK, let me sum up...Gates says, "Don't use this hose on these fittings." Rotax, CPS, and FD say, "Never mind what the manufacturer of the hose says, we supply it - use it anyway!" What is wrong with this picture from a safety standpoint! Or from a legal and ethical standpoint.

And Roger, please don't say that these statements are the mechanics fault - these statements have nothing at all to do with the mechanic, they are from the hose manufacturer, the engine manufacturer, the airplane manufacturer, and the reseller of the hose.

1. Gates says 2 things
   
   1. 
      
   2. Barbed fittings and rubber hose are not compatible
       
      
   3. Gates does not endorse aviation applications.
      

[*]Rotax, according to Roger Lee uses Gates as OEM hose

 

[*]CPS claims

1. They have no way of knowing what kind of fittings their customers have.
    
   
2. FD changed the fittings to barbed fittings. CPS claims this and that they have no way of knowing it.
    
   
3. That the kit 'developed for the Flight Design CT' only means that you can rely on the amount of hose being sufficient, not that the hose is appropriate.
   

[*]Flight Design says:

1. Use good quality replacement hose.
    
   
2. Based on info submitted on prior incident they cannot fault Gates hose and agree it is an isolated incident.
   

My personal conclusion is that quality control at Gates is not sufficient to use their hose on barbed fittings where the stem size matches the hose size. Beyond that given demonstrated failure of the hose, coupled with the manufacturers refusal to endorse for aviation applications I don't see how anyone can use it, recommend it or resell it for 5 year fuel line replacement on aircraft.

[chanik]

But ultimately, and according to the FAA, it is FD who must define the parts to be used and they have been conspicuously silent. CPS shouldn't be guessing and Roger or other mechanics shouldn't have to call around and play detective to figure this out. "Use good quality' is certainly not being compliant with ASTM standards. I wouldn't give much weight to Gates' refusal to endorse aviation apps. No company would, or in this litigious market, should rationally open themselves up to the liability. Your DCPR8E NGK spark plugs, the only ones you are supposed to use, are also not supported or approved for aviation use by NGK.

[Tom Baker]

OK, let me sum up...Gates says, "Don't use this hose on these fittings." Rotax, CPS, and FD say, "Never mind what the manufacturer of the hose says, we supply it - use it anyway!" What is wrong with this picture from a safety standpoint! Or from a legal and ethical standpoint.

And Roger, please don't say that these statements are the mechanics fault - these statements have nothing at all to do with the mechanic, they are from the hose manufacturer, the engine manufacturer, the airplane manufacturer, and the reseller of the hose.

 

Doug, time for a few facts. Neither Flight Design or Rotax supply Gates hose for replacement on our aircraft. Rotax uses Gates hose as part of an assembly that they manufacture. They do not say to replace the hoses with Gates hoses. The assembly is a fuel pump with attached hoses. They used to say that when changing hoses to replace the fuel pump if came with the hoses attached. They now say to change all fuel pumps at 5 years, hoses attached or not. The hose fittings supplied by Rotax could be called a barbed fitting, but they do not have the sharp machined edges that some fittings have. I don't think these fittings could do damage to the hose.

 

Flight Design uses 2 styles of fittings. One style is like a bulbed fitting that Gates says is OK for rubber hose. The other style is a brass fitting with sharp machined barbs. This fitting is kind of like a fish hook. It goes in easy, but it is not going to come out that way. It has been my experience that I have had to cut the hose off these type fittings. Here again Flight Design does not sell Gates hose for these fittings.

 

I don't know about what CPS sells or says about the hoses, but I do know it is up to me as a mechanic to decide if what I am using is correct for the application.

[Tom Baker]

But ultimately, and according to the FAA, it is FD who must define the parts to be used and they have been conspicuously silent. CPS shouldn't be guessing and Roger or other mechanics shouldn't have to call around and play detective to figure this out. "Use good quality' is certainly not being compliant with ASTM standards. I wouldn't give much weight to Gates' refusal to endorse aviation apps. No company would, or in this litigious market, should rationally open themselves up to the liability. Your DCPR8E NGK spark plugs, the only ones you are supposed to use, are also not supported or approved for aviation use by NGK.

 

Flight Design from the begining has had part numbers and specification for the hoses listed in the parts catalog. I don't know how this is being silent.

[Doug G.]

I just hope no one gets hurt or worse because of this issue. In my case I have three years before I face this, but I am the mechanic, owner, and PIC of my plane. I hope the issue is settled by then.

[Ed Cesnalis]

Flight Design from the begining has had part numbers and specification for the hoses listed in the parts catalog. I don't know how this is being silent.

 

Tom,

 

You are correct that FD has not been silent. As a result of the incident this spring FD issued a 'Resolution of Safety Alert regarding CPS fuel hose kit'

The letter concluded 'After discussions with CPS who worked with their supplier, the mechanics where the problem occurred and carefully reviewing the information we were provided, we believe that the contamination was an isolated incident not specifically related to the type of fuel line sold by CPS.'

 

FD is wrong, this is not an isolated incident. There are about a dozen events reported here and more on similar forums.

 

These discussions are resulting in two camps. One camp is vehemently protecting the status quo at the expense of the mechanics which begs the question: 'How likely is it that this many mechanics are the problem even after some have them have done the 5 year change without problems?'

 

One of the problems is the 'coded' language used. When the 'isolated incident' cause was determined it was, in my opinion, a polite way of blaming the mechanic, more so than saying t his was isolated. The people involved in the 'investigation' knew it wasn't isolated, some had taken steps in their own shops to prevent re-occurrence.

 

As a community we should be able to at least admit this is not an isolated incident and if we do we can actually define a more full proof procedure.

 

To this day Gates Fuel Injection 5/16" hose is advertised/sold by CPS with this language: "It was developed by Roger Lee for the Flight Design CT" The danger is that other suckers like me and my mechanic will rely on 1st the isolated incident determination and 2nd that developed for the CT by Roger means that the hose is appropriate. If you use that hose on your CT you will realize rubber debris. This remains a bad situation.

[Eddo]

I have been following this topic for a while. I have watched many a CT and other LSA aircraft get a hose change and my 2006 CTSW has been done as well with the same hose. It seems like the people that have actually never done a hose change seem bent on blaming the hose. The experienced mechanics here seem to use the same hose, but don't have the problems. If you listen to most of them they'll tell you it is the install technique that is bad.

I think after watching these guys work I'll put my money on the experienced installers that have been doing this procedure time and time again without any issues. They have actually performed a lot of these and aren't pointing any fingers at the hose.

Looks like teaching new installers a better way is the key. Maybe the the first timers should be talking and asking questions of the experienced mechanics about the hose change and not taking it for granted it's an easy job. There must be a reason all of the experienced guys aren't having all these issues. From what I have seen with all the hose changes at my field Charlie Tango's was an installation issue. He should just have that mechanic read and re-due the fuel hose. For about $60 in hose, $20 in clamps and 4 hours or so of labor it would be done. Issue solved.

[Roger Lee]

Hi Ed,

 

I hear tell this coming week you are replacing your 5/16" fuel injected rubber hose with more FI rubber hose.

The 1/4" (Aeroquip) isn't an FD part number and only one parts dealer for the CT in the US even uses it. (For shame! ) Aeroquip uses screw on style fittings. It isn't for barbed fittings either and it's has even less give than the other FI hose. I bet if you called Wurth in Europe that hose isn't for aircraft. I take it your taking all the barbed fittings out for the rubber FI hose since you found it it shouldn't be used and is a safety hazard?

 

The 5/16" FI rubber from FD is actually a lower quality from the better spec Gates Barricade Greenshield Technology hose. Look at the European brand Wurth hose spec (DIN) and see what it is rated for as far as liquids. Why pay another mechanic to do the work, why not the original one for free as far as labor?

If someone doesn't pay attention again on the install your results will be the same, but I know the installer this time and your in good hands. I have known him for years and he has done some hose changes. You'll be flying the friendly skies again by next weekend.

[Ed Cesnalis]

Roger,

 

>I hear tell this coming week you are replacing your 5/16" fuel injected rubber hose with more FI rubber hose.

The 1/4" (Aeroquip) isn't an FD part number and only one parts dealer for the CT in the US even uses it. (For shame! ) Aeroquip uses screw on style fittings. It isn't for barbed fittings either and it's has even less give than the other FI hose.

 

The hose that you use isn't an FD part number either, why should the standard be higher for me than it is for you? Only one parts dealer that I'm aware of continues to have rubber debris contamination issues. Lockwood has solved their issues by using fuel lines that gives a better/good result. Lockwood started with Gates and like you realized contamination, their solution is Aeroquip 1/4" and the Tecnam OEM for 5/16" John's selling points are: a substantial inner wall and better size matching with the CT's barbed fittings. I talked to John and Aaron at Lockwood and both told me that approval was obtained from FD. Doesn't that make them equivalent with CPS approval wise? The amount of give isn't the issue its the amount of damage that concerns me.

 

>I bet if you called Wurth in Europe that hose isn't for aircraf.

 

The Wurth hose installed without damage and lasted 6 years, no debris at all. This is not only true in my aircraft but fleet-wide as far as I know. I would use Wurth over Gates and Lockwood was willing to sell me Wurth if I wanted but they advised that the hose they are using is best quality available so I'm going with that. The Wurth hose needs to be 'popular' or it sits on the shelf too long. Lockwood's Wurth hose has been there 1 1/2 years.

 

>I take it your taking all the barbed fittings out for the rubber FI hose since you found it it shouldn't be used and is a safety hazard?

 

Someone like you or FD needs to take the lead here. I tried to source the parts and did not succeed. For now I will be happy to get my aircraft's fuel system back to original condition.

 

>The 5/16" FI rubber from FD is actually a lower quality from the better spec Gates Barricade Greenshield Technology hose. Look at the European brand Wurth hose spec (DIN) and see what it is rated for as far as liquids.

 

With the exception of Larry's hose the issue has been mostly barb damage and the DIN specs do not address the smoothness vs waffle texture of the inner wall. The specs mean nothing when it comes to the type of damage that I realized.

 

>Why pay another mechanic to do the work, why not the original one for free as far as labor?

 

Beyond simply saying 'Roger, Kevin and Eddo' said its your fault I don't see how I can fault Art. Art began with guidance from FD giving the Gates from CPS the OK based on your testing. Next Art used the same procedures that he used on the prior install, one where CPS shipped the kit without the Gates fuel line and Art got Gates line from Napa. The variable here was not the mechanic and his installation but rather the fuel line and its soft/loose/waffled inner wall. If you doubt that this difference is dramatic simply compare your photo of your smooth inner wall Gates line that held up and compare it to my photos where the inner wall is not similar to your Gates line or other fuel lines. I have brought this issue up to you many time but you never comment on it.

 

>If someone doesn't pay attention again on the install your results will be the same

 

I still have various fuel lines and fittings on my desk. If I insert a fitting into the waffled Gates line from CPS I do get the same results. If I insert the same fittings in other lines, like my original Wurth line or other smooth inner wall line there is no apparent damage. 'Paying attention' makes no difference.

 

How can you keep defending the line that you stopped using 2 years ago in order to stop realizing rubber debris contamination? How can you keep endorsing it 'developed by Roger Lee for the CT' ??. If you really wanted your name off of there it would be gone long ago. Pick a side Roger.

[Roger Lee]

My last post was kind of unfair. :blush: I already knew the answers and was just giving you a hard time about rubber hose. It has always and will always be your only practical option. I knew you had to use it again.

CPS's whole catalog is changing which includes the removal of my name which should have never been there in the first place. I have been talking to all parties involved since the first or second post of this entire thread.

I'm not defending that hose or anyone's hose because it really doesn't matter. There are just too many brands and type ratings used in the LSA field from us and other countries and it looks like it all works. Are there better choices over some, absolutely. I switched a long time ago to Gates Barricade Greenshield carburetor hose that has a smooth inner liner, slight give over FI hose and rated for the worst of the fuels anywhere in the world and works very well with any fitting. Whether people believe it or not it's actually a step above standard fuel hose because of its liquid ratings and in some cases its multi-liner design..

Technically unless Lockwood, but you more specifically has a written LOA in hand verbal really doesn't work.

It has never mattered to me which hose anyone has ever used since there are many brands and types out there and many will work just fine as proof from all the different types we find on different LSA's, but if you do a poor install the results will be the same with anyone's hose. You can damage or contaminate any hose with an improper install and un-sterile technique. That's been my whole point all along. Use whom ever hose you want, some absolutely need more precautions, but if done correctly and carefully with any of them it can be done without all the mess.

I'm happy that you will be back in the air soon and that was where I was trying to get you to all along. You and I enjoy flying on a regular basis so sitting on the ground with a solvable problem would never work for either of us. If I had been there I would have been happy to do the replacement myself for free since we have been friends for so long.

(But you would have had to help me )

 

Happy New Year to you and Erin!

Say Hi to Erin from Lynn and myself and don't let the snow get over your head. It's just too damn cold.

[Ed Cesnalis]

One thought Roger,

 

If the Gates hose that you switched to has a run that isn't smooth you might end up with a new hose to prove.

 

I crossed the Sierra one more time with my extra fuel filters this time, and I arrived in Tracy apparently all clogged up again. I flew home behind a 914 and took these photos.

[CT4ME]

Awesome pics!

[Ed Cesnalis]

Jeremy found another problem beyond the rubber debris that explains the symptoms now.

 

"two of your floats have been rotating on the the guides in the float bowls. When they rotate inwards they shave a groove into the float from the float bracket and this groove starts to get hung up on the bracket from time to time causing either fuel starvation or flooding in that carb."

[Safety Officer]

Yep,

Time to replace all the floats. That wouldn't explained all the debris you had in your system, but could definitely be part of the carb issue. The bowls could have been checked for rubber verses float particles to really help you out. Carbs should get rebuilt by either hours or year time table. They will usually last 5-8 years and or 1000 +/- hrs. It isn't an exact science and they need to be checked. There is nothing in writing from Rotax that says exactly when to do a complete rebuild. there is a 200 hr. inspection. Some just do it at the 5 year rubber replacement time for a complete rebuild.

[Ed Cesnalis]

...The bowls could have been checked for rubber verses float particles to really help you out. ...

 

I thought the same thing but then realized that it didn't matter. The rubber debris from the fuel lines / fittings was a hazard and represented damage to my fuel system and needed to be corrected back to original condition. Same with the floats, they were a hazard, they were damaged and contributing contamination so they needed to be corrected as well.

 

I realized fuel starvation to half my engine multiple times and either issue or both could have been the cause(s).

 

In retrospect the things that would have really helped me out would have been:

• More understanding of rubber fuel lines fitted with barbed fittings at time of fuel line replacement.
  
  • They are not compatible but none the less are used on our aircraft so a work-around must be employed. The hose/fitting combination must be such that the mechanic can insert the fitting with a minimum of damage to the hose.
    
    • Testing inserts then cutting away allows for inspecting the amount of damage being done. Such a test install should be done and cut away prior to final install.
      

  [*]Hose kits sold as "developed for the FD CT" are misleading if the hose needs to be rejected due to severe incompatibility with the barbed fittings. Truthful advertising would have helped me out.

  [*]Catching the damage to the floats at the condition inspection, prior to the floats sticking.

  [*]Catching the damage to the floats when first trouble shooting the power loss.

  [*]A bag of beaded fittings as a Christmas present from Flight Design complete with published procedures/instructions on replacement of barbed fittings.

[Doug G.]

I can't disagree with any of that.

[FastEddieB]

I know its an old thread, but this seemed as good a place as any to post this...

 

Last May I got a head start on my Sky Arrow's 5-year rubber parts change by installing new fuel lines (all except one hard-to-reach one, done in Tucson in October with help).

 

Following Benson's Ninth Law (fuel line is fuel line), I just went to NAPA and bought 10' of the right diameter fuel line off of their blue dispenser/display. Did not even think about different types or brands. I think it was Gates Barricade of some description, but not fuel injection.

 

In any case, no real problems with debris, in spite of no real precautions or special procedures being followed. Again, in Tucson we replaced the one remaining hose and installed an inline fuel filter to the line coming off the fuel pump.

 

I'm in the process of doing my annual, and the float bowls looked pretty good, but not perfect:

 

Left:

 

8450724656_f0248b1bb9.jpg

 

Right:

 

8449638861_5fe1c9ce56.jpg

 

Not bad, but not perfect. Its not easy snaking the float bowls out, so there's a chance that crud may have fallen in while doing so.

 

In the left bowl there was also a fleck of something white, near the left circle.

 

For the record, MOGAS always goes through a Mr. Funnel with filter, and my gascolator has a very fine screen which was pretty clean.

 

 

PS - any idea why these links from Flickr are not embedding properly with "img" tags - they always have before. I had to resort to "url" tags to get them to show up at all.

[Ed Cesnalis]

Works for me in a reply but I can't add an img to your post. If I look at the source of your post, after I test adding the carb image, using the editor I can see that the domain is getting stripped from the image url. Must be a bug in the add image tool triggered by something in your post.

 

 

 

[Roger Lee]

Hi Eddie,

 

Try putting the pictures on your computer and them uploading them here. If that works maybe something changed on Flicker. Nothing has change here on the forum. I'm not having any issues with uploads, but they always come from my desktop and I always re-size them. Also make sure they are not too big or they won't upload. As they say size matters.

From all the bowls I have ever pulled off over the years they can be clean to down right loaded with crud. Some with fine particles of dirt (normal in a tiny amount), some with water, some with hose flecks and some with silicone. Silicone usually looks like a clear to slightly opaque soft gooey substance. Some particles make you wonder how they bypassed the pump filter. Dirt particles from the air filter wouldn't show up in the bowl. I just finished a Tecnam hose change and pulled the bowls because they wanted new needle valves. The bowls had a small amount of fine dirt particles (247 TTSN).

[Mac Bowden]

Another bit of information regarding debris causing rough running which is being blamed on Ethanol in petrol. Seems you aren't even supposed to scrape the floats with your finger nail !

http://www.bmaa.org/files/defect_alert__0042_-_rotax_carburettor_floats.pdf