Teflon hose life

[jetdriven]

Our first annual inspection as owners is underaway.  the hoses forward of the firewall are Parker 124F001 and -008 teflon hoses installed in 2001. .  Our IA thinks that the hoses have a 7 year life limit,  although the service manual says "on condition". 

 

He wants to have them replaced. I am hesitant.

SO what does "on condition" mean to your IA /A&P and what is the basis for replacement?

Thanks

byron

[sleepingsquirrel]

On condition: chaffed and leaking, burned and leaking, kinked creating a weak spot, cut and leaking, etc. I just had my annual completed and the AP told me that the teflon hoses would be intact and working long after he and I were gone. That they would never need to be changed.

Good luck, My annual was right at $990.57 , I got a new baggage door hinge, a nose tire replaced (I supplied the tire) , 14 hours in labor for the inspection and a few hours for researching the ADs and the repairs. My bird was as clean as a whistle with not ONE AD hanging.

[jetdriven]

We have 1200$ in parts and perhaps 1000$ in labor / shop rent.  A set if Teflon hoses is going to blow that to hell.

 

[sleepingsquirrel]

I expect the $37 baggage door hinge to pay for itself on the next XC flight. My mechanic said that the front of the door was popping up and acting like a speed brake. I wondered where that draft was coming from!

[231flyer]

Teflon hoses should be good for life according to Mike Busch.  He has a whole series on unnecessary MX.  Please find a link below;

http://www.eaavideo.org/video.aspx?v=991383595001

[kris_adams]

I may be confusing hoses, but I thought my A&P said every 12 years. I had a lot of other stuff done on my first annual so we waited and did my hoses at the second annual.

Good Luck

[Sabremech]

No life limit on Teflon hoses. I've had them on our F86 for years. 

[OR75]

Ask the IA to show you the data. He is expected by the FAA to use valid data and information for the work he wants to do.  

Teflon hoses are to be replaced on condtion with no time limit. If there is a leak or if the steel braiding is chaffed or broken, that's a good reason to replace.

 

I believe (not certain) that rubber hoses with Steel braiding are also replaced on condition. Without steel braiding ... 5 years.

 

 

 

[garytex]

My mech says that they last practically forever.  Your mechanics' statements would make me wonder why such things come out of his mouth.  

Taint that far from Houston to Sunrise Beach.  

[M016576]

Quote: jetdriven

Our first annual inspection as owners is underaway.  the hoses forward of the firewall are Parker 124F001 and -008 teflon hoses installed in 2001. .  Our IA thinks that the hoses have a 7 year life limit,  although the service manual says "on condition". 

 

He wants to have them replaced. I am hesitant.

SO what does "on condition" mean to your IA /A&P and what is the basis for replacement?

Thanks

byron

[PTK]

A couple years ago I was inquiring and urging my mechanic to change the hoses. It was explained to me, and he showed me the id tags on the hoses, that they don't need replacement. As he explained to me it is a fairly big job as the engine has to be raised out in order to get to them. They are usually replaced at OH. Look at the tags yourself and ask someone else for another opinion.

[N601RX]

If he feels that way about the hoses, then how does he feel about running the prop past the 7 year recommended limit? I had a mechanic tell me that my prop had to be overhauled because it was 8 years old and had 26 hours on it a few years ago.  We called Hartzell and they just laughed and said no.  This and a few other incidents forced me to educate myself and find a new mechanic.  Best thing I ever did.  We My firewall foward hoses are 9 years old, but are still soft and flexible with no wear.  I have noticed the oil pressure and fuel pressure line behind the panel are still original and plan on replacing them.  They are getting pretty brittle.

[AndyFromCB]

It really comes down to how you want to maintain your airplane. The reason why turbine aircraft are so reliable is not just the engines. It's because they follow a recommended schedule of maintenance and replacements of parts, whether they are needed or not.

Bravo got new hoses at last annual, not sure it needed it, but 7 years seems to be an accepted practice in turbine world. If I wasn't flying it for business though, with the associated pre-tax dollars used, I don't know that I would have done it myself. They all seemed just fine. But I don't recall that being a requirements, just something my mechanic recommended. He also recommended looking at fixing my tank leak, which is about a drop every month and I just had a good chuckle and asked him which kid needed braces now ;-)

My take on propellers is to have them looked over and re-sealed halfway thru the engine life, or 6 years. Big giant gyro spinning up front and if it goes so do I. I'd take an engine failure over a prop failure any day. About $1500 vs an $3000 to $4000 for an overhaul.

[Sabremech]

In the Corporate jet world, hoses are on condition. We don't change them unless they are leaking, chaffed, etc. 

No 7 year requirement!

[AndyFromCB]

Sabremech,

Depends on the hose and manufacturer and type of maintenance being followed. If 121 or 135 and the manufacturer mandates a service life of 5 or 7 years, then it must be replaced on calendar. Learned that a while ago while considering going in on a Conquest to be leased by a 135. Every damn things needed a 8130/yellow tag. Needless to say, it didn't work out.

Good news is AeroQuip does not place a lifelimit on their hoses.

Andy

[PTK]

I never seemed to be able to reconcile this 121 or 135 thing! I guess a 135 soul is more valuable than one on a 121? 

[AndyFromCB]

Well, of course, all animals are created equal, it's just that some animals are more equal than others. I really shouldn't have said part 121 because I have no idea how airlines work but there is a world of difference between part 91 and part 135 maintenance requirements. As to 121, I assume it has to be like 135 if not even more stringent?

[OR75]

the airlines (121) maintenance is usually done continuously based on an agreement with the FAA. Different airlines may have different maintenance programs.  The result is the same level of requirement as part 135 (with both serving paying passengers) but part 121 are left with more flexibility on timeline so they can manage their fleet.

The keyword for part 121 is than maintenance is continuous.

[Sabremech]

Hi Andy,

 I don't even consider part 121 or 135 on this board. I'm not aware of too many Mooney's that would be part 135 and certainly not 121. So just sticking with what the majority are ( Part 91) the teflon hoses are on condition.

 No need to delve into the other parts when they don't apply.

[OR75]

http://www.sacskyranch.com/h_life.htm

good read on the topic ...

 

[Immelman]

I'm not a hose expert but I recall specifically being told that one of the pros of going with a teflon hose was that it lasted longer than the usual 7 years with a non-teflon hose.

Maybe a call to PHT (precision hose) is in order to get their opinion on how long one hose type lasts vs another?

[Sabremech]

The inspection program I wrote for our North American F86 Sabre has Teflon hoses with "on condition" for the life limit and is approved by the FAA. These hoses are used at each of the flight control actuators where it goes from rigid to flexible. Also the Dassault Falcons I maintain have Teflon hoses and I've yet to change one since I've been working on them (1993). They are "on condition" as well. 

If you want additional information, contact your PMI at your local FSDO. I'm certain they can give you the exact reference.

[AndyFromCB]

Sabremech,

I only brought up 135 because it is where I seek guideance towards maintance. Those rules are the for a reason. To me, if I cannot afford to maintain an airplane under part 135 equivalent means I cannot afford the airplane. I try to be fairly informed owner and do a lot of maintenance work myself, especially trouble shooting/component removal. Reinstallation, etc, I get my mechanic involved who by the way works for an annual flat rate as an advisor only. The actuall work gets performed by another shop. You could call him my director of maintenance.

All I am trying to say, look to 135 when a question comes up. Those rules are there for a reason and huge part of their safety record. I hate this boards sometimes when people complain about a set of hoses, or a propeller needing to be looked at after 12 years of hanging there or 35 year engines. At the very least we are all maintaining what would be a $300,000 machine today. It's going to take time and money to do it right so when I hear Mike Bauch's name it makes me want to cringe. Snake oil salesman.

You got one engine, is your life really that cheap than a $2000 set of new hoses every 7 years is too much? Or a propeller reseal and repaint for another $2K every 6 years? You can't just stop and pull over. Or a third set of eyes during any maintenance.

If you ever see any of my tail numers in the NTSB, I guarantee you, it won't be maintance releated because I couldn't or didn't want to save up a few bucks a day to keep my machines in as new condition as possible.

How often does that falcon get looked at. If it's flying and making money, I bet you weekly. A lot easier to maintain things on condition in that situation than an average owner owned aircraft being flown twice a month on a long cross country. Airplanes only come in two ways. All squaks identified and fixed or all squaks not identified yet. Nature of making things light enough to fly also makes them of lightweight and not as durable as say a semi truck.

[KSMooniac]

Just because a component is new doesn't mean it is any safer than one in service already... look at the infant mortality on all kinds of parts these days that is likely due to cost-cutting.  We've had rashes of bad cams, cranks, and cylinders that triggered ADs from all sorts of manufacturers, and then there is no shortage of anecdotal evidence about various alternators, fuel pumps, vacuum pumps, turbochargers, mags, etc. failing within the first few hours of use due to defective production or service, or errors made by the installing party.  Every preemptive component change increases the chances of getting a bad part or an installation error (which you probably mitigate by being a diligent owner, like me).

You cringe at the mention of Mike Busch, but he does sell as a service to act as a "director of maintenance" exactly like you describe with your mechanic!  He has ample evidence after a long career in this field to back up his decisions.

[AndyFromCB]

I agree with infant mortality. That's why it's a discussion board. I run into the same issues all the time. My Arrow flew for 40 years, 20 of them JA Air maintenance before anyone noticed some "strange repairs" from 1970 in the left wing. Damn thing was flying just fine for 40 years, but in the end I did blow alway $14K getting the issues fixed.

I don't know where to draw the line between preventive replacement and infant mortality possibility. Just bringing up the other side of equation into the question. Now if only my speed brakes weren't vacuum, I could get rid of that pump with the upcoming Aspen upgrade, but on the other hand, now I'll have a vacuum gyro as my back up;-)