Gates Barricade standard carb fuel hose

[procharger]

What size fuel line runs from wings down to engine and how much is required

for total replacement CTSW thanks ?

[Tom Baker]

I posted totals in my parts list. It is the 7.5mm hose.

 

[Roger Lee]

The hose from the fuel bulkhead with the sight tube is only about 6" long. It is 5/16". It slides over a metal tube that runs down the "A" post into the engine compartment.

[Tom Baker]

10 hours ago, Roger Lee said:

The hose from the fuel bulkhead with the sight tube is only about 6" long. It is 5/16". It slides over a metal tube that runs down the "A" post into the engine compartment.

The hose is 7.5mm not 5/16", 5/16" is 7.95mm. I know you choose to use the 5/16" hose because it is cheaper, but it is to loose for my standards. The parts manual specifies a size and standard for the hose, and as far as I am aware Flight Design has not provided and approval for the 5/16" hose. It even became an issue when some mechanic used it on a CTLSi on the pressure side of the fuel injection system and the hose came off under pressure.

[Tip]

Where can you purchase 7.5 mm fuel hose?

[Roger Lee]

Been using 5/16" for 15 years and no issue. The .4mm (four tenths of 1mm) difference is negligible and actually fits better over barbed fittings and won't damage the inside liner. You can't pull my 5/16" hose off any fitting without tearing the hose. I'd say that is a tight fit. I have tested this twice. The hose will rip before it moves off those fittings.

If you want to see a really poor fit look at the hose the FD puts on the 912iS engine that comes off the fuel filter and into the first fuel rail. Their fitting is way too small and even using an Oetiker clamp will allow it to easily slide off. Ask me how I know and I even posted a bulletin on it. You must use a Band-It clamp like FD does from the factory to CRUSH the hose far enough so it won't slide off.

[Jim Meade]

Roger, did you have get an LOA from RD to us the 5/16" hose?  I know you do extensive documentation on your work, do you write in the aircraft log that you changed from 7.5 mm OEM hose to a non-standard 5/16" hose per LOA, or do you just note the hose change without specifying it's a different dimension?  There is often discussion in SLSA circles over what original part the owner or mechanic can change on an SLSA on his own and what needs an LOA and I'm wondering about your experience with this.  I'd think a fuel line would be an item of interest to everyone.

[Tom Baker]

11 hours ago, Tip said:

Where can you purchase 7.5 mm fuel hose?

Airtime Aviation imports the OEM hose, and Flight Design USA sells a different brand. I have also used hose from a BMW dealer that meets the DIN specifications. The labeling on the hose is confusing, but it is the right size and works well. There is a brand called CRP that is out there, and I think CRP stands for crap. Where the other hoses will make a nice radius it wants to kink. The 7.5 mm hose is certainly more expensive than the Gates 5/16" hose, but that is the price to pay for following the rules.

[Tom Baker]

9 hours ago, Roger Lee said:

Been using 5/16" for 15 years and no issue. The .4mm (four tenths of 1mm) difference is negligible and actually fits better over barbed fittings and won't damage the inside liner. You can't pull my 5/16" hose off any fitting without tearing the hose. I'd say that is a tight fit. I have tested this twice. The hose will rip before it moves off those fittings.

If you want to see a really poor fit look at the hose the FD puts on the 912iS engine that comes off the fuel filter and into the first fuel rail. Their fitting is way too small and even using an Oetiker clamp will allow it to easily slide off. Ask me how I know and I even posted a bulletin on it. You must use a Band-It clamp like FD does from the factory to CRUSH the hose far enough so it won't slide off.

Roger, I agree that there are some fittings that the 5/16 hose fits better, and the 7.5 mm hose is really tight. But there are some fittings that will fall out of the end of the 5/16" hose without a clamp. Those fittings will leak if the clamp is not tight enough because the hose is to large for the fitting. 

For the 912iS if you use the correct size hose for the fitting you don't have issues. That .4 mm is a big factor then.

[Roger Lee]

You really don't want to go here. If you pick on one item you can't turn away from the hundreds of other items. There are many technical things that aircraft Mfg's don't follow themselves. Even FD. The hose issue is a non event in this case. Even Rotax uses Gates hose. If you want to get picky about the hose then you are required to order from FD any part that they have assigned a part number and you can not substitute. Then you call FD and they send you a different part from a local store or tell you where to buy it somewhere else. That comes right from the FAA legal. If you are worried about the hose then you should really worry about the whole thing and not just one item. Read the parts manual and see how many of you use parts that have an FD number.

 

Screws, nuts, bolts washers, engine rubber mounts, front end dampeners, door struts, cowl cam locks, exhaust springs, air intake tubings, K&N air filter, clamps and the list goes on.

 

Plus hose wasn't supposed to be originally used over barbed fittings. AN fittings is a better choice. When you use the 7.5mm hose over some of the barbed fittings it scrapes the inner liner and sometimes causes rubber particles to go downstream. I have first hand knowledge of these things happening. This is anouther reason I don't use fuel injection hose on the carb engines. It has no give in the hose and causes issues with the inner lining and it cause the barbs to cut into the hose when clamped down. 

I don't do anything without some physical research, seeing first hand issues or talking with the powers to be. 

Plus just because a MFG does something doesn't make it good or right or even legal at times. I have corrected and had changed several things from different aircraft MFG's and they changed their books. Where do you think several of the FD LOA's have come from. 

[Roger Lee]

Tom, "For the 912iS if you use the correct size hose for the fitting you don't have issues. That .4 mm is a big factor then."

You need to take a closer look at the hose size on the fitting where it comes into the fuel rail next to #3 cyl. The FD fitting is way to small for the hose size and will come off if the wrong clamp is used. Even an Oetiker that barely fits on the hose is not enough to squeeze the hose down far enough to hold it from coming off.

[Ed Cesnalis]

Gates says their barricade is not compatible with barbed fittings the barbs do cause damage and introduce debris  There is no correct size.  Beaded fittings are correct for this type of hose.

[Roger Lee]

Hi Ed,

"Gates says their barricade is not compatible with barbed fittings the barbs do cause damage and introduce debris "

Exactly and yet everyone does it. Even FD. That's also my point. Technically you aren't supposed to use barbed fittings. AN hardware for aircraft. They are smooth.

So when trying to be overly technical where do you stop? Look at the number of aircraft Mfg's that use barbed fittings. 

[Ed Cesnalis]

18 minutes ago, Roger Lee said:

So when trying to be overly technical where do you stop?

I say stop short of mixing barricade and barbed fittings.  It is a meaningful safety hazard.  I had to return to the field from a low altitude in a hostile environment and no motor thanks to the debris polluting my fuel system after a light sport repairman did the hose change.

[Roger Lee]

Hi Ed,

That's because your mechanic didn't know what he was doing. Poor sterile technique, using FI hose and over tightening the clamps. It wasn't the hose's fault.

[Ed Cesnalis]

2 minutes ago, Roger Lee said:

It wasn't the hose's fault.

if the correct beaded fittings where used it couldn't have happened.  it was the fault of the fitting/hose combination.  Even with your 'sterile' technique the barbs puncture the inner lining of the hose causing both debris and leakage beyond the inner lining. 

[Roger Lee]

"if the correct beaded fittings where used it couldn't have happened.  it was the fault of the fitting/hose combination. 

It will happen to the 7.5mm too.

Then you need to complain to FD and all the other Mfg's.

Using the 7.5mm hose will cause floaters too. Not blowing the hose out after you slide it in the fire sleeve, using the wrong cutting tool, forcing it over the barbed fittings because the hose opening is a tad too small (7.5MM) using too much clamp pressure that cuts into the inner liner causes floaters and causes early deterioration of the hose under the clamp. 

Just using common sense and getting some decent training that all things are not created equal will solve all your issues. I've done tons of hose changes on all LSA and I don't have all these issues.

Research and education can go a long way. Complaining never solves problems. Research and solutions do.

 

p.s.

Once an LSA Mfg certified their plane to make it sellable they took responsibility for all parts on that aircraft whether its good or bad. Good luck on trying to change some things. I have tried.

 

[Jim Meade]

Roger,

Who in FAA legal, or what document?  I'd like to see it, as well.  Thanks.

Did you or did you not get an LOA to change hose part numbers?  If not, what is your basis for the change if you get sued by someone who has a leaky fitting which is involved in an accident or incident?    I mean, if there is a problem and someone says, "who put this hose on here and on what authority" in court, what do you say?  As Tom say, the correct hose is available.  How does one defend a change unless there is an LOA?

 

 

[Jim Meade]

I have a question about the discussion over industry standards and best practice in such examples as the hose and barb we are discussing here.  The FAA has said that SLSA manufacturers can call certain maintenance shots.  If the manufacturer has used, calls out and provides parts and materials that many would not consider acceptable, where does one stand in challenging that position?  FD sells airplanes with barbed fittings and rubber hose.  These aircraft are reviewed by European regulatory bodies using published standards the FAA defers to.  What right does one have to argue that because some people think an item is less than optimal, that this perspective overrides the guidelines of the manufacturer who has to face the regulatory bodies?  

It seems to me there is probably some basic way in how to resolve these apparent conflicts.  Does anyone have history or can site precedent for how this dilemma is resolved?

[Madhatter]

I have eliminated all barb fittings and banjo fittings on all engine fuel fittings and soon will do all fittings and hoses on the airframe except for the wing root hoses. All new hoses are what you find in certified aircraft, lifetime teflon with silicon firesleeve. Same goes for the oil lines using AN fittings at the next rubber change. Overkill? I guess  but I won't have to deal with them again and they are much better and not as expensive as you would think. And yes I am ELSA .

[Tom Baker]

6 hours ago, Roger Lee said:

 If you want to get picky about the hose then you are required to order from FD any part that they have assigned a part number and you can not substitute. That comes right from the FAA legal. 

Roger, that is not quite right. I may have not been working on light sport aircraft as long as you, only since 2007, as an A&P I have been working on airplanes a long time. I have been an IA for over 30 years. Being an IA one of the ways you can renew is by doing training with the FAA. The FAA riling has been discussed in these training sessions since before the light sport definition was even formed. Here is an example Cessna list a wheel bearing with their part number in the parts catalog, and the description is simple wheel bearing. You pull the bearing out of the wheel and it is a Timken 12345. Even thought you can buy Timken 12345 since Cessna didn't specify Timken 12345 in the parts catalog you can only replace it with the Cessna part. Piper on the other hand also list the wheel bearing in their catalog with a Piper part number, but in the description it say Timken 12345. In this case it is okay to replace the bearing with a Timken 12345, that does not have the Piper part number. They are the same bearing, but it has to do with how it is listed in the parts catalog. So for Flight Design any part where they list a specification and size for the part it may be sourced from anywhere, but if it just has a Flight Design part number and says hose it must be bought from them. That is what the FAA legal ruling says in a nut shell.

[Roger Lee]

Tom,

This is what FAA told me.

 

[Tom Baker]

2 hours ago, Roger Lee said:

Tom,

This is what FAA told me.

 

What they told you is partly true, but there are exceptions.

[Roger Lee]

I have talked with several factories over the years about buying parts locally and or not from them. Most didn't care.

That's my point. 5/16" or 7.5 mm. Mfg's don't really care. Look at the parts you buy from me. The original door lift struts were only 190 psi and I got them to 220. The original red polyurethane dampeners were 20mm wide and now 25mm.

[Jim Meade]

I understand that everyone is expressing heart-felt understandings and beliefs, but it sure would be nice if posts could include or cite names, places, times, documents and so forth.  Otherwise, it turns into "trust me".  When we talk about maintenance procedures, our work should be able to be cross-checked and reproduced.  We're all human and we're all subject to selective recollection or understanding, especially in an emotional discussion.  If it comes down to "trust me", we are really dealing with personalities and not facts.

I think I recall very few of my "show the source" inquiries answered.  Not answering them is answering them.

If a poster is forced to say, "I heard it at school" or I heard it at an IA refresher course" it would be better if one could say about when, about where, the instructor if remember, etc.