Ask the A&Ps 5-year Rubber Replacement

[Jim Meade]

General Aviation is the only significant category of aviation that does not use Reliability Centered Maintenance (RCM) as the basis for maintenance.  Read this article to see why airlines, the military and other major aviation entities use it.

https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-03_the-waddington-effect.pdf

Here is an AvWeb article discussing Maintenance Induced Failure (MIF).

https://www.avweb.com/ownership/the-savvy-aviator-53-the-dark-side-of-maintenance/

This 2021 article talks about the downside of maintenance.  It reveals the fact that MIF was found to be an issue in WWII.

https://www.aopa.org/news-and-media/all-news/2021/march/pilot/savvy-maintenance-ri

It is tempting to conclude that GA would be better off to use maintenance procedures more inline with airlines and the military .  It seems generally accepted that maintenance is best done using the right material and good procedures by skilled mechanics and overseen by knowledgeable owners.

In my opinion, we should worry more about people knowing now to check their hoses than about when to replace them.  Replacing them at an appropriate time will follow if we inspect them carefully and on a timely basis.

[airhound]

Why aren’t IA’s required for ACI’s for SLSA.

 

[EricB]

On 12/17/2023 at 10:13 PM, Roger Lee said:

Look on these two websites. The pins show people that can help. 

https://rotaxflyingclub.com/locator

https://rainbowaviation.com/?page_id=4854

Great resource.  Many thanks for sharing that.  I've got a good guy now but who knows what the future holds.

[Madhatter]

It doesn't take a regulation to make a mechanic good. It takes a mechanic that is competent and who doesn't cut corners to be good. It doesn't even take a certified person to do things right. It takes someone who does their homework and doesn't give up. I don't need the FAA to tell me how or what to do as most of them don't know themselves,  those days are long gone. If you want good maintenance you have to do your homework and lots of it. If you are mechanically capable then get educated because things are not going to get better, there is a 12,000 A&P shortage right now in the US, and most don't consider LSA a career objective. 

[airhound]

We all need to have our work checked. Even the best make serious mistakes.

[Madhatter]

5 hours ago, airhound said:

We all need to have our work checked. Even the best make serious 

Of course everyone makes mistakes, I've been working on aircraft for 51 years and luckily no serious mistakes and hope never. It used to be that you could call the FAA and get very experienced advice and help, I even had one take his coat off roll up his sleeves and show me a new trick or two. That won't happen anymore. Some of the work I've done recently there was no one in SC to ask, I had to call someone in Idaho for advice. I had to do a lot of homework on it as there was pretty much no one left to consult on a Wright 1820 1450 hp radial. These engines were on a DC3, B25, B17, T28, most of these people are dead.

[airhound]

Why do Certified Aircraft need IA sign offs and SLSA don’t ?   What’s the logic?  Bueller…..Bueller

 

 

 

[FlyingMonkey]

7 hours ago, airhound said:

Why do Certified Aircraft need IA sign offs and SLSA don’t ?   What’s the logic?  Bueller…..Bueller

 

 

 

The idea behind the LSA & Sport Pilot rules were to reduce expense, complexity, and regulations.  They wanted to reduce barriers to entry into aviation.  In some ways it worked, in some ways it failed.  The new MOSAIC rules are designed to address some of the shortcomings of the older rules and make things more consistent.  We'll see how that pans out.

[Tom Baker]

9 hours ago, airhound said:

Why do Certified Aircraft need IA sign offs and SLSA don’t ?   What’s the logic?  Bueller…..Bueller

 

 

 

Many in general aviation don't have a good understanding of the privileges of an inspection authorization. Many seem to think it is some kind of super mechanic, but an IA has no maintenance privileges. Anytime they are performing maintenance they are exercising the privileges of an A&P mechanic. The training to become an IA consist mainly of how to search regulations and find the data required to perform inspections of major repairs or alterations. So the reason an IA is required for annual inspections of standard category aircraft and not SLSA is because the complexity of determining whether the aircraft is airworthy due to the regulations and varying certification standards.

[Jim Meade]

It is nice to have the teflon hoses so i don't have to take firesleeve off to inspect the hoses.  

Since hoses are on nearly all airplanes that I know of, and the vast majority of GA certificated airplanes have hoses changed by A&P based on condition, not time, it should be easy to ask any experienced A&P how to inspect hoses.  My experience is I say "you don't have to sign anything - I'll sign it off" and A&Ps are generally quite happy to help and even teach.  I don't recall learning how to inspect hoses when I got my EAB plane certified, nor when I took the 16 hour class from Rainbow, but I did learn how when I took the 120 hour class from Rainbow.  My point is there is expertise available and I agree with those who say we should attain and practice it.  Tom's earlier discussion was a helpful reminder of key points in hose inspection.  Sure, time is a factor.  One of several.

[Madhatter]

2 hours ago, Jim Meade said:

It is nice to have the teflon hoses so i don't have to take firesleeve off to inspect the hoses.  

Since hoses are on nearly all airplanes that I know of, and the vast majority of GA certificated airplanes have hoses changed by A&P based on condition, not time, it should be easy to ask any experienced A&P how to inspect hoses.  My experience is I say "you don't have to sign anything - I'll sign it off" and A&Ps are generally quite happy to help and even teach.  I don't recall learning how to inspect hoses when I got my EAB plane certified, nor when I took the 16 hour class from Rainbow, but I did learn how when I took the 120 hour class from Rainbow.  My point is there is expertise available and I agree with those who say we should attain and practice it.  Tom's earlier discussion was a helpful reminder of key points in hose inspection.  Sure, time is a factor.  One of several.

No certified aircraft use the hoses we use on LSA. A lot of certified hoses can go way over recommended time and be functional, not that it is recommended. A lot of 303 steel reinforced type hose is used with a pressure rating of 3000 psi. I don't care for it and would rather use AE701 or teflon, 666, etc. The hose we use in LSA is junk compared to certfied and will deteriorate much sooner. Someone would feel like a dumb ass when trying to explain that trying to save $20 caused an accident its not worth it, just my opinion. 

[Jim Meade]

My comments were addressed to the probability - I'd almost be willing to call it a fact - that most GA A&Ps have considerable experience in evaluating hoses based on condition.  I didn't specify what type of hoses.  I stand by my assertion that we can learn a lot about hose inspections from an experience GA A&P.

[Madhatter]

I was just indicating that it is two completely different scenarios. There is no similarity between certified and LSA other than it's a hose. Certified doesn't use barb fittings or automotive hose. All certified hoses have AN or MS end fittings.  Other than 303 hose and except for a few AD related issues most hoses go to the TBO of the engine. I would never remove firesleeve on a certified aircraft to inspect the hose, if I suspected an issue it would be replaced. Just doing hoses on a T28, manufacturer recommends replacement after ten years, most of it is 303 hose. You don't see the kind of issues in Roger's photos on certfied. 

[Tom Baker]

 

1 hour ago, Roger Lee said:

I have found A&P's fail far more than LSRM-A's on Light Sport aircraft which seem to be backed up by FAA incident facts and even Rainbow Aviation. When I pull a cowl I can many times tell the owner that an A&P worked on the engine. They always ask how did you know. I tell them that this is wrong and that's  wrong and this is illegal. Plus it doesn't matter what initials are next to their name in any profession. It's up to the individual with any license to be at the bottom of the barrel or the top. Just like Doctors, lawyers, cops, fireman, ect, ect.  Logbooks are the same. Most A&P and other mechanics are lazy in their book entries. Then I see A&P's making a short garbage logbook entry and say they inspected the SLSA under part 43. I get calls from certain businesses to question mechanics about their work and logbook entries. 

It's the individual that makes what they do good or bad in any profession. Most times the mechanic ends up giving the other people's money back.

Read the person and not the credentails.

Just because you have the most eloquently written logbook entries doesn't mean the work is any good. I would much rather look at an airplane and see neat tidy correct work that a novel of logbook entries, but that's just me. 

[Tom Baker]

Here is an example of an oil hose I removed from a CT last fall. This connection was at the oil tank, so it was easy to inspect. Who knows how many mechanics looked at this and let it pass by. This was my first time inspecting this airplane.   

Here is what the hose looked like after the fire sleeve was removed.    

Here is the date code on the hose, remember that it was replaced last year.    

The ID of the hose was squeezed down to about 5/16" from 1/2". How did that effect the flow of oil through the hose. The hose is a substitution, and not genuine Rotax hose. The hose ID is 1/2" instead of the specified 12mm. 

[airhound]

Other than selling LOAs and parts back in the day,  FD USA, Connecticut,  played a main role in QCing/educating owner/operators (the checkers), LSRs and A&Ps (maintainers) on the CT’s unique/different maintenance tasks/requirements. They provided Safety Value Added. Then after a good run, things changed, they went away.
so, could CTFLYER fill a fleet void with:

SavvyMx - $899/year for piston singles.
“Our flagship plan includes everything in SavvyQA plus a dedicated A&P/IA account manager who interfaces directly with your shops and mechanics. SavvyMx covers all your scheduled and unscheduled maintenance including your annual inspection. Also, if you're looking to purchase an airplane, the service includes one Savvy-managed prebuy examination per year at no additional cost. “

wore that one out….

[Madhatter]

I use Aeroquip 1/2" hose with no issue as well. As for firesleeve the Band-it clamp only needs to be tight enough to hold it and should be placed over the solid fitting area as to not crimp the hose. The above photo of the crimped hose is the work of an amateur who probably should not even work on a lawn mower in my opinion.  We all make mistakes but this was lack of doing their homework. 

[airhound]

Generally as an owner operator when I look at all manner of hoses I rarely see that the ends have been dipped with the expensive stuff nor even diluted RTV.  What’s with that?

[Madhatter]

1 hour ago, airhound said:

Generally as an owner operator when I look at all manner of hoses I rarely see that the ends have been dipped with the expensive stuff nor even diluted RTV.  What’s with that?

Don't need it, use silicone tape.

[Tom Baker]

4 hours ago, airhound said:

Generally as an owner operator when I look at all manner of hoses I rarely see that the ends have been dipped with the expensive stuff nor even diluted RTV.  What’s with that?

If I replace the fire sleeve the ends are always sealed. I normally will dip them, but there are certain cases where I use silicone tape. If I am not replacing the fire sleeve, I will leave it like it was installed at the factory.

[Jim Meade]

Roger, when a mechanic replaces a Rotax called-for 12mm hose with a 1/2" hose, how do you recommend the mechanic writes that up in the detailed logbook entry?  Should it be obvious to the owner exactly what hose was used?  Should it be spelled out that the hose is a substitute for the hose specified in the manual?  I believe you use a substitute fuel line, too.  

[FredG]

"Logbook labels give insight to a person's ethics."

Sorry, Roger, but this statement is completely over the top.  Is it really necessary to defend detailed logbook entries (labels?) by claiming that mechanics who don't write them are unethical?

[Jim Meade]

How do you log a non-standard hose?  Yes, we're still on hose.

Your comments on ethics and log book entries are off-the-wall.

[Madhatter]

You guys haven't seen bad ethics until you see what's been going on in the last 20 years with used certified aircraft.

When I make the comment to a used aircraft salesman that I know about how atrocious some of his planes are, even bordering on criminal, he tells me. "There is a sucker born every minute but I will make a lot of money on it". Most of you guys have no clue on how bad things have gotten. A lot of these 50 to 60 year old planes are so worn out and corroded, restoration is almost impossible. The FAA no longer makes rounds at local airports and even if they did , most wouldn't know what to look at, I know these guys, I could write a book on stupid things they've done.

Be glad you have fairly new planes.

[FredG]

Profiler?  Really?  Stuff like that just derails an otherwise useful discussion.  Unfortunately.