Line Maintenance Course

[Doug G.]

Someone asked me to say something about the Rotax Line Maintenance course I took recently at Leading Edge Airfoils in Lyons, WI. I believe there were two weeks of classes going on starting with the basic maintenance and ending, I believe, with the heavy maintenance (overhaul) course.

 

There were about eight participants at the line maintenance weekend with a variety of reasons for taking the class. Two of us were working only on our own planes, a couple of others were A&Ps finding that there were Rotax engines around needing attention, and others were established LSRM-As who owned their own businesses or looking to start a business. Some had taken the basic maintenance course the week before and were continuing through this one.

 

The center of the course was the tear down of a 912 on the bench. (The engine was one that overheated because of a radiator leak that was not repaired. The owner thought it had enough water and also thought the CHT gauge was not working correctly. It showed water in the overflow bottle, but it was actually overflowing this bottle in flight and the owner never checked tank on top. --So, that became lesson #1.)

 

We disassembled everything down to the crankcase leaving the case, crankshaft and camshaft untouched since spitting the crankcase is the job of an overhaul trained specialist. The process involved removing and inspecting the carbs, gearbox, the water pump, the charging system (coils and triggers) and the electronic modules, the starter and sprag clutch, the fuel and oil pumps, the heads, rocker arms, push rods and lifters, and the pistons.

 

Then we put it all back together again. All this was done in the manner prescribed in the Heavy Maintenance Manual. This is, in a sense, the secret book since it is not available on-line and you cannot purchase it - you have to take the class.

 

There were some tricks learned (ex. the rings have to be positioned in a specific manner before the piston is inserted) and there are a number of special tools which can be quite expensive (some of them can be made). There are things that the assumption would be that you could use an automotive tool but in many cases you cannot, at least without the possibility of damage to the engine.

 

Although I hope I do not have to use any of the information I gained, if I do have a problem I will have a much better sense of what is going on and where, and how, to look. There are basically three things Rotax does not want you to do after this class: 1) split the crankcase, 2) repair the gearbox, and 3) overhaul the carburetors.

 

It was worth the cost. My only frustration was that I planned to fly, but the winds at home were gusting to 31kts and it felt like more - I didn't want to have issues just getting to the runway - so I drove nine hours each way. (That's the one real negative about owning a plane, driving is not as fun as it once was!)

[FastEddieB]

Good info - sounds worthwhile.

 

 

 

Then we put it all back together again. All this was done in the manner prescribed in the Heavy Maintenance Manual. This is, in a sense, the secret book since it is not available on-line and you cannot purchase it - you have to take the class.

 

 

Seems to be up online:

 

http://www.rotax-aircraft-engines.com/portaldata/5/dokus/d05014.pdf

 

[Jim Meade]

Sounds consistent with my experience. Everyone got a chance at "hands on" although sometimes you had to be a little pushy as some students would hog the engine and not let others in unless you spoke up. I think we had more in our class so hands on time for Doug was probably not an issue.

 

We checked that the crankshaft was still assembled at the right angles while we had the engine stripped, and I bet Doug did, too. This is the check you make if it goes overspeed or there is a prop strike.

 

As Doug described, I found everything we did was exactly according to the manual and that there were some tricks or tips in how things went together easier but no "secrets". I remember the tools discussion and how to make some otherwise very expensive tools or when there was a work around.

 

I, too, found it to be a good course and worth the money for me.

 

 

 

 

[Doug G.]

Hmmm... My apologies, I am guessing that the instructor was referring to the overhaul manual that is not available. I probably mistook what he said.

 

One other negative was that things that were talked about while we were working were difficult to take notes on. Once in a while when something was very specific I took the time to jot it down.

With the smaller class I was able to do everything I thought was helpful, mainly the things that were different from my experiences with other engines. With eight if us and four cylinders getting hands on was not difficult. A few things were done more than once so we could each do them.

 

I agree there are no secrets, but there are things that are not explained sufficiently in the manual that it helped to do, and see done since my limited engine experience (I have torn down and overhauled an auto engine.) would have had me doing things incorrectly in some cases.

 

I am also questioning the limitation on carburetor overhaul on an engine that is out of warranty since we toe down these carbs in the Rainbow LSRM class. The rule is, " You can't do it unless you've done it." and we tore them down and reassembled them in class. (It will come down to price vs. time for me when the need arises.)

[Roger Lee]

Doug: "I agree there are no secrets, but there are things that are not explained sufficiently in the manual that it helped to do, and see done since my limited engine experience (I have torn down and overhauled an auto engine.) would have had me doing things incorrectly in some cases."

 

Jim: "I found everything we did was exactly according to the manual and that there were some tricks or tips in how things went together easier but no "secrets".

 

 

Hallelujah, Hallelujah, Hallelujah. I'm about to break out in song. :lol:

 

 

I have been trying to tell you guys there are no secrets for years, not all things are in the manuals and there are tips and tricks and that the only good way to get this is through education in class and not from Joe next door. The Heavy Maint. class is even more enlightening and you learn even more how far from a Continental or Lycoming the Rotax really is. Believe it or not the Line maint. class only scratches the surface and gives you a good firsthand look into the Rotax design and maint. differences.

 

Tips and tricks, you've got to love'em and they they do make life easier and there are more to learn.

 

So what I am reading between the lines here is it was really worth going to class because owners and mechanics need this to really understand the Rotax and its differences to other aircraft engines.

 

 

p.s.

Jim,

There really is a secret society and now you and Doug belong to it. Congratulations!

[Doug G.]

Glad we could make your day Roger. That secret Rotax handshake is something else though.

[Doug G.]

I don't know if owners need to go through this if you are happy with letting someone else do the work, don't have the time, or, you are not mechanically inclined.

 

Mechanics who are going to do this type of work do need this.

 

(Iwill not be taking the overhaul course since I will never have the prerequisites and I do not plan to do any overhauling.)

[Roger Lee]

I think all owners should go through the Line Maint. course even if you never touch a wrench. You own a high dollar engine that you are hanging your life on and you should know something about it. It will help you understand your engine, what can go wrong, where to look to solve problems, what to tell a mechanic if you have a problem, what to tell the mechanic because he didn't go to school, how to fix minor issues that only take a minute, how to change plugs and oil the right way and what not to do. The list goes on. Education can do nothing, but enlighten. I applaud anyone who steps up and takes to course just to learn.

 

Even if it's just for the secret handshake.

[sandpiper]

p.s.

Jim,

There really is a secret society and now you and Doug belong to it. Congratulations!

 

I went to class Roger, but I never got the secret "Encoder Ring"!!

[Roger Lee]

The encoder ring cost an extra $5k :blink:

[Doug G.]

 

 

I went to class Roger, but I never got the secret "Encoder Ring"!!

It comes in the mail... eventually.

[Jim Meade]

Hopefully, all will gain some perspective from the discussion. There was in my class none of the operating secrets that Roger talks about all the time. Maybe Doug would comment on whether there were operating discussions that suggested practices outside the manual were preferred. It's always interesting to observe Roger change his mind and agree with someone else, then claim that he was right all along.

[sandpiper]

Didn't the manual, at one time, suggest filling the exhaust springs? I seem to remember Eric tucker telling the class I was in not to do that.

[Roger Lee]

Hey you're using the emoticons (smiley faces).

 

Most manual practices are good to go. There are a few tricks that many experienced long time Rotax mechanics use and those are those tips and tricks you learned. There are many more and in one class you could never get all of them and each instructor has different preferences. After your class you then realized you knew more of those than before and didn't think that guy on the other forum was so dumb after all and new tips and tricks will just keep on coming. Every time I spend time with Eric I always come back with new and better info. I have never had a class from anyone, but Rotax even though there are other instructors.

 

Jim,

I fully admit I was wrong once this year, but it was about the vacuum cleaner. My wife told me so.

I'm absolutely wrong at times and then I will post a correct answer when I find out differently.

 

When I give info it either comes from a high up Rotax source or a distributor and I don't pull it out of a hat. I had to have heard it or was taught it from someone. Sometimes when an answer isn't obvious I call or email Rotax and get the current thinking. Given the limited detailed info given in our forum text (nature of the beast on any forum) there is no way anyone can cover all contingencies. This is why I usually prefer phone calls for a little more detailed and interactive info gathering. Some times it's just your best guess and it may be general in nature until more detailed info emerges so I give the most common causes. Not standing in front of an engine and doing an individual diagnoses makes giving advise no better than a doctor trying to diagnose over the phone and then yes you can be absolutely wrong. Different terminologies, experience levels and engine understanding can make a text driven diagnoses tough at best. Some times I absolutely need to correct myself from a previous post at times and sometimes I will admit to baiting for answers and comments in the hopes that looking it up makes the learning stick better.

 

 

What's important to me?

We all seem to get it done one way or the other here and it helps everyone and makes our LSA ownership more fun and adds to our comradery. Then everyone gets to solve their problem or learn an answer to any question they may have from whom ever has that answer and sometimes there is more than one correct answer. Our forum is like an interactive encyclopedia group. Kind of like skinning the cat, many ways to accomplish it, but some are just a little easier (and saves more meat).

[Roger Lee]

Hi John,

 

Your absolutely right not to fill the exhaust springs. I just inspected an RV12 SLSA yesterday. The springs were filled and not safety wired (amongst a few other small items). I sent Vans a suggestion list that coincides with the manuals and SB's.

The problem with filling springs is it retains too much heat and it doesn't have any air flow through it to dissipate the heat so they many times prematurely fail before they would without being filled. Current teaching (actually has been for years) is put the RTV silicone on the outside of the spring and safety wire the spring. This was confirmed years ago with a phone call to Rotax.

 

John,

 

If you go over to Vans you'll see my list addressed to Scott. They were all minor. Vans has another company assembling the SLSA version.

 

There are a few things in the manuals that the SB's have changed, but the manual has not. The only way to catch these is to read the manuals cover to cover then read the SB's, SA's and SI's.

[Jim Meade]

Roger,

 

You never shared with us the answers to all the questions you were going to get out of the Bahamas course.

 

No, I think the deal is that while the Rotax manual may be better in some places than in others, that there is no information needed up through the courses that I took that one needed to go outside the manual on.

 

In particular, I am talking about operating practices and procedures that you claim comes from your high level courses and which is not available unless one sits at the knee of Eric Tucker.

 

I simply don't believe it. I think what it does do is let you claim you are an expert and others can't contradict you. What we have on one hand is my reference to documents and your reference to inside information.

[Roger Lee]

So we're on the topic of manual info or what's not in the manual.

 

If everything is in the manual I take it you won't need to ask any more questions?

 

Jim, quote

"No, I think the deal is that while the Rotax manual may be better in some places than in others, that there is no information needed up through the courses that I took that one needed to go outside the manual on.

 

Up to your level means you are going to limit your knowledge just to that point.

 

 

Here's the most simplest and amongst the many for you that aren't spelled out in the book well and leaves owners scratching their head at your level.

 

What does the manual say the low idle rpm is for the 912ULS? answer 1400

So what did your instructors say about idle rpm set point on the 912ULS 100 hp? It wasn't 1400

 

The manual reference all three engines and cross references are not clear.

You don't have to believe it's your plane, but some tips & tricks are better and different than the manual and the manual isn't good in some areas. teachings and info changes and the manuals don't keep up or they wouldn't have SB, SA and SI come out and not put it in a manual for a year or more.

 

Believing is not always documentation:

We all know we are the only ones in the entire universe. Yep that must be true, it isn't documented there is anything else. just faith based.

 

You don't seem to have faith or trust in anything without documentation.

You believe as many others in a life manual with poor documentation and scientific facts. I don't knock it and all can believe, but it it is based on faith. The Bible.

This statement may upset you, but it's the truth or we would have better documentation and not so many instructors of that manual giving their interpretation.

You don't farm by the manual, you do some things your own way. Why?

 

 

So like you said:

" I simply don't believe it. I think what it does do is let you claim you are an expert and others can't contradict you. What we have on one hand is my reference to documents and your reference to inside information."

So what do I say to each Reverend, Preacher or Rabbi.

That's not what the manual says.

 

Sorry Jim,

The info is out there on forums and classes everywhere, you have to have faith in your mankind that they have your best interest at heart and try to help you when they can. I have faith in Eric and others that when they tell me something that isn't in the manual they speak from 30+ years experience and new teachings from the factory. I learned new stuff from Eric this last class that isn't in the manuals.

We are all free tyo believe what we want.

[Jim Meade]

Be happy, Roger.

[Roger Lee]

I'm always happy and I wake up happy and all smiles and that drives my wife nuts. (Like most, slow in waking)

 

That's what drives my wife and friends crazy. They always want to know why and what's so funny all time. Being a fireman for 30 years gives you a sick sense of humor. Even when people are mad at me there is humor there, of course that just makes them more mad. The only people I tend to make mad are the mousey types and I get along with the opinionated people better because they have an opinion and I respect that and they really don't care what others think because they have their own opinion. The opinionated people tend to want to know the correct answers to things to so they are more likely than the mouses to seek and dig for answers.

[Doug G.]

Had to dig to find this thread. I got my credentials today for the line maintenance course I took last September. It only took ten months! Better late than never I guess.

[paul m]

If I didn't congratulate you then I'm congratulating you now Doug.

[Doug G.]

Thanks, Paul.