Sky Arrow Annual - mostly ROTAX

[FastEddieB]

Thanks, guys.

 

I'll do it again at the tail end of the annual, with the engine warmed.

 

The only sound I heard was gurgling. I will check next time that the plug adapter is snugged down.

 

Also, this time I was using a very small compressor that could barely make and hold the 87 psi. I'll use a bigger one next time.

 

Last year, using 80 lbs and less than 30 hours ago...

 

#1 80/76

#2 80/76

#3 80/69

#4 80/74

 

And Roger, I just pulled up the procedure from the ROTAX Maintenance Manual:

 

"The maximum permissible pressure drop is 25 %, e.g. from 6 to 4.5 bar (87 psi to 65 psi). If the pressure loss is less than 25% then the valve seats and piston rings are working properly."

 

http://www.rotax-owner.com/pdf/compression_912.pdf

 

Maybe you misremembered by one order of magnitude?

 

Edited to add: I just noticed that in your first post you also quoted the 25% figure.

[Roger Lee]

Hi Eddie,

 

The permissible is 25%, but nobody has that unless they have a serious issue. Watch the Rotax compression test video on the Rotax owner forum. They also say 2.5% is normal.  78/80 is normal or 83-85/87 is normal.

We teach in class to look for issues even with a 10 psi drop. 

When you were here did I do a compression test?

 

If I had a 60/80 I would panic because I knew an expensive repair was in my immediate future.

 

 

http://www.rotax-owner.com/en/videos-topmenu/elearning-videos/181-diff

[FastEddieB]

I'll check tomorrow.

 

The language is confusing.

 

On the one hand, up to 25% is "permissible" and means "the valve seats and piston rings are working properly".

 

On the other hand, somewhere "normal" is defined at a level one tenth that of "permissible".

 

In any case, I'm not worried. I'm in spec regardless, and the engine seems to be running strong. And even if my numbers are low, they seem consistent and steady.

 

Worst case? Major repairs or replacement. I don't anticipate either, but even that would not be the end of the world!

[Anticept]

There's a saying in the field.

 

Manufacturers know how to build the engine.

 

Mechanics know how to MAINTAIN the engine.

 

Often, good manufacturers will take input from the field to tune their processes and refine their manuals. Happens all the time. 25% is permissible, but highly unusual and usually warrants investigation anyways. It means you are a lot closer to safe limits and, depending on your philosophy, might be time to take a closer look.

[Tom Baker]

Unless your compression tester has been calibrated recently I would look to it for being the issue. Based on 35 years working on airplanes and seeing many different compression testers they all seem to have their own personalty. That is why some get the 80/80 numbers and others get 75/80 when testing the same cylinder.

[FastEddieB]

As an update, I spent 4 or 5 hours at the hangar yesterday and today and I'm just about finished up. May do the test flight and return-to-service tomorrow.

 

The BING "Bent Tube" arrived yesterday and I got it installed today. Right before coming home this afternoon I did a run-up (after catching a float bowl that was not quite seated properly) and...

 

EUREKA!

 

Started immediately and settled right into a smooth idle - none of the roughness that I had before for a minute or so after startup.

 

I think I was a victim of "post hoc ergo propter hoc" fallacious reasoning. The roughness started right after installing the new ignition modules, therefore the roughness must have been because of the new ignition modules. Obviously not the case - it was the left "choke" not closing all the way after application, due to the broken "bent tube", but gradually vibrating shut over a minute or so.

 

By the time I'm all wrapped up I'll probably have spent around 20 hours over five days getting this done, essentially solo. Did have help removing/replacing the horizontal stabilizer, "blocking" the stick to check flight control linkages, but that's about it.

 

I'm probably going to pass on another compression check, and just do one next time I'm de-cowled for any reason.

 

I am very pleased at the way the Sky Arrow is holding up after seven years and just over 400 hours. A lot of the innards look like they're from a brand new model plane. I credit the quality of the parts and materials 3i chose, and my annual fastidiousness cleaning and applying lube or CorrosionX as appropriate.

 

But it is all rather exhausting work, both mentally and physically and I'm about worn out. Kudos to full time mechanics that do this day in and day out - it must not be an easy living.

[Roger Lee]

With those compression numbers you can't leave us hanging in suspense. I would love to know what your compression is hot.

 

How long had the engine sat before the cold test?

[FastEddieB]

I had flown it for a few tenths a day or so prior to warm up the oil.

 

Though it did not fly much last year, it rarely sat for more than a few weeks.

 

If I feel motivated, I may throw the gauges on it warm. If I do I'll report the results.

[Doug Hereford]

Eddie,

I may be too late with this, but I would recommend a very close look (and tap test) at the main gear leg attachment points. There is a shelf assy that the legs bolt on to. This design is not optimal in my opinion. It is also somewhat hard to inspect being a dark color (carbon fiber). We operated a 600 sport for several years and approx. 1500 hrs. The shelf failed (possibly due to a rough landing or landings). 3i provided engineering for a repair that included and additional channel below the gear legs at the attachment. This repair scheme was an improvement, but still poor in my opinion. 

 We actually discovered the issue on a condition inspection by noting that one wing was lower than the other.

Closely inspect the horizontal stab attachment and wing attachments. We always removed the horizontal during condition inspections for a close look and lubrication.

Our compressions were always varied. I never got too worried about it, and they seemed to correct right about the time I thought we were going to have to perform major surgery.

Just another minor point that I am sure you are already aware of, The access plate for the fuel sump needs to be checked on each pre-flight for proper orientation. On our plane (we actually had two for a short time), one could install this plate with the retention tab in the wrong place. I always worried that the plate could come off in flight. The next stop for it then would be the propeller. We added some alignment marks to it to help with a visual verification for correct installation. Interesting to note, that the certified version of the 600 has a very robust hinge/latch assy. for this plate.

 

Doug Hereford

[FastEddieB]

Doug,

 

Thanks for the detailed info. I will comment later.

 

In any case, I did the compressions warm this morning:

 

 

So, between being warm, tightening the adapter a bit more and using a bigger compressor, most came up a tiny bit.

 

And Roger, you did do them a couple years ago:

 

 

Right now, I'm not going to worry. But I will probably keep checking them periodically when I have the cowling off.

[Roger Lee]

Hi Eddie,

 

Because your numbers are fairly consistent warm or cold, but way lower than I would expect I now tend to think you need some new gauges. My numbers previously are right on the money with everyone elses I do and I check my gauges periodically. The numbers we got when you were here was from a cold engine. A 1-4 psi drop is normal, but a 7-10 psi is not. 

 

Since you are done with the inspection it should be fairly easy to check the gauges for accuracy.

 

 

p.s.

You do have the correct orifice size?

[FastEddieB]

Roger, they are fairly new, only used a few times. Bought from Lockwood or LEAF or somebody specifically for the ROTAX

 

They look like this, though that was an abortive attempt, with the Torque-Seal index in the wrong place:

 

 

 

Any hints as to how to calibrate them?

 

BTW, I did my "return to service" test flight just now and everything went perfectly. Had my cap-mounted GoPro running and I'm uploading a little video of how to reduce a crosswind component. I'll probably post a link to that shortly in a new thread.

[Roger Lee]

Hi Eddie,

 

I think you already know, but remember LSA does not get a "return to service" after an annual condition inspection. It must be "found in a safe condition for operation". Read the last sentence I put in your book last time. It should be similar.  

 

http://www.faa-aircraft-certification.com/experimental-lsa-operating.html

 

Quote from Circular: FAR 21.191(i)(1), (2), or (3)

 

"23. Condition inspections must be recorded in the aircraft maintenance records showing the following, or a similarly worded, statement:

 

“I certify that this aircraft has been inspected on [date inserted] in accordance with the scope and detail of FAR 43 Appendix D or the manufacturer’s inspection procedures, and was found to be in a condition for safe operation.”

 

The entry will include the aircraft’s total time-in-service, and the name, signature, certificate number, and type of certificate held by the person performing the inspection.

 

The words don't have to be exact, but should at least be in the same ballpark.

 

So many mechanics especially A&P's get this wrong and have poor documentation to boot. A 3 line logbook entry for an annual that lasted 2-4 days is a sin.

 

 

 

p.s.

I documented. This may make Jim faint. 

[Roger Lee]

To check your gauges use a known verified pressure source and or against another set of verified pressure gauges.

[FastEddieB]

Thanks.

 

For the actual endorsement, my Operating Limitations give the exact wording for it:

 

"I certify that this aircraft has been inspected in accordance with the scope and detail of Appendix D to Part 43 or the manufacturer’s inspection procedures, and was found to be in a condition for safe operation."

 

I have been making a second logbook entry with specifics, something like this:

 

"Tested ELT operation and battery status, both satisfactory. Other annual checklist items performed and documented on 3i supplied checklist, on file. All work performed in accordance with AMM or accepted practice. Ground and flight tested and OK for return to service."

 

That 3i checklist, 5 pages long, is made part of the aircraft's permanent records. If that's technically incorrect, well, its technically incorrect. Sorry, I try to document everything I do for a future owner or the FAA, but I really don't sweat the really finicky paperwork stuff. Since its your living, I understand your increased scrutiny of the exact language used.

[Roger Lee]

Are those the only two sentences you have for your annual in your logbook? I'm a believer in check list and keeping them as you saw when you where here. Check list technically aren't legal records that you are required to have, but can be discoverable in court or by the FAA be used by either. The one legal record that really should be complete and not shortcutted is the logbook entries. These are legal documents and there for your protection and for legal information should that time arise. Keeping good records has proven to keep an aircrafts value up to $5K-$10K more than a logbook that has bare minimum entries.

[FastEddieB]

Are those the only two sentences you have for your annual in your logbook?

For the inspection, pretty much. I just put in the logbook any repairs that were made. In the engine logbook I again put maintenance performed - oil change, spark plug maintenance, air filter cleaning, parts replaced, that sort of thing.

 

Like I said, my Annual Condition Inspection checklist is 5 pages long. I am not going to log 5 pages of routine inspection items in my logbook each year. A potential buyer will have access to all the records on file, by year.

 

If, in spite of that mountain of paperwork he or she wants to offer me $5k or $10k less because of where the routine inspection items were logged, so be it. I think my records are quite complete - more so than most. Just not everything goes in the logbook.

 

So shoot me!

[Roger Lee]

You can tell I had nothing better to do this afternoon.     

 

 

http://www.rotax-owner.com/en/rotax-blog/item/22-good-documentation-its-everything

 

 

The problem with, "I would want the logbook to say the inspection had been done in accordance with the pertinent reqs." or the all inclusive "IAW" statement, is that most of the time when I see this and question the mechanic or owner if he did an inspection check item the answer is no or I didn't know that had to be done or I don't have time to read the manuals or even where to find the manuals or the SB's.

 

Believe it or not this is the rule and not the exception. I have had two instances where I was ask to question a mechanic on CT's about work he performed.  Both logbooks said IAW, but they both left lots of things out of the inspection. In both cases the companies took their money back. I have done this many times for my own edification to see what was done by the last mechanic because the logbook was so bad. Many times the mechanic says that was 6 months ago how am I supposed to remember. Holy Cow!

 

 

​I just had a client for the first time come to the shop with a 2007 CTSW. The logbook said IAW and had lot's of 3 line annual inspections comments since 2007. You couldn't tell if it was an annual condition or a 100 hr. inspection. It took me 3 pages of discrepancies and a 4 page logbook label in small print to fix and correct all the things done to this or flat out not done over the years. It cost the owner twice as much because it could have been done right the first time at the same cost as doing it wrong and it had many unexpected cost due to things not done. The Dynon software was 3.0 which is about 2007 software. Never checked, never updated and not a single logbook entry, but it was done IAW. The problem was the A&P mechanic wrote IAW and failed to do many things and did illegal things. He has never been to a Rotax school, has no manuals, no SB's no FD documentation, improper tools and this list goes on. 

 

The term IAW actually opens you up for even more litigation because you just stated you did everything that Rotax and let's say FD wanted done for the inspection and you left nothing out. You said in IAW and that's all encompassing. If you forgot something or didn't know it existed because you haven't kept up on all Rotax  and FD's bulletins and manuals your toast with no leg to stand on or legal defence in court. A reasonable logbook entry is about a page long. It isn't a 2-3 liner. It isn't that tough to do. All you are is a secretary because all you are doing is writing down what you did. I spent a lot of time in court over my 30 years in public service for civil and criminal trials. If you came from the medical field like me you know all too well how important documentation really is. When the lawyers gave the classes back in 1979 I took it to heart and listened. I have never been burned in court thanks to those teachers. I can always tell the ones who have never been in court because they have never been raked over the coals or lost a suit because of poor documentation. That is your only protection. They will hirer 5 mechanics that do a good documentation job and know the manuals and SB's backward and forward. They will eat you for lunch and you'll look like the worst mechanic ever by the time they get done. 

 

IAW should be followed by some explanation of worked performed.

The mechanic must have checked for tightness on some bolts as prescribed by some on going SB's, or done a compression test, cleaned the air filter, checked the over load clutch in the gearbox, and the list goes on. Everyone here says they want all hose to be an on condition item. I have never seen a single entry of any mechanic stating that he at least looked at the hoses and they were found to be in good condition. There are some special checks done every inspection and if it isn't written that you did it how would anyone ever know?

How many here know if on the last inspection their mechanic lubed all of their rod ends  or flap rods, aileron bearings, ect.... But it says it was done IAW. How about the two planes here with the loose teleflex stab cable nuts. Bet these didn't happen overnight and no one ever looked until it was coming apart, but the inspection was done IAW.

 

There is nothing wrong with the term IAW it's just the lazy documentation that follows at times.

Like an instructor told me once. You can be in the top 10% or the bottom 10%, it's your choice. I never saw anyone do well in life or brag about being in the bottom 10%.

 

Do you want a mechanic that documents that he was thourgh and you can actually read what he did or one that has three lines and you have absolutely no idea if he did what was right or required and was done with your safety in mind?

 

Who wants to buy a business with a contract that is only 3 lines long or property. It's like buying a pig in the poke and so is IAW without anything behind it to support it.

 

​Who in their right mind would buy a plane if the only entries said IAW. If that's all there was how would you know if anything was really done. I'm not a fan of mechanics saying it's on file. Businesses go out of business, computers crash, get viruses and hard copies at a business get lost or get damaged. So where does that leave a customer. IAW, says it right in the logbook so it must have been 100%.

[Roger Lee]

Anyone that has ever been to my shop for an annual how did you like the documentation for your annual? Was it informative? Do you think it helps the next mechanic to see what was done or if there was any repeat issues. Without good documentation how does anyone know if an issue is a repeat problem.

 

Eddie you're included. Would you have been happy with your logbook label for the work I did to your plane if all I said was IAW? Or do you like that it was explained and you got all the paperwork instead of me just saying it was on file and you had no idea what was on it?

[Tom Baker]

Roger, you are so high on your soapbox that the lack of oxygen is getting to you.

 

An inspection is not maintenance. An inspection is an inspection. The regulations tell you that you must do the inspection IAW "in accordance with" whatever documentation is pertinent to the airplane you are working on.

This is from 91.327 for light sport aircraft.

(2) A condition inspection is performed once every 12 calendar months by a certificated repairman (light-sport aircraft) with a maintenance rating, an appropriately rated mechanic, or an appropriately rated repair station in accordance with inspection procedures developed by the aircraft manufacturer or a person acceptable to the FAA.

 

What you are griping about is the recording of maintenance. It is commonly accepted to make a maintenance entry along with a inspection entry, but it doesn't need be made that way. I agree that in many instances mechanics do not do a good job of making maintenance entries.

 

Also I would like to point out that there is no requirement to put anything in a logbook, but rather it is to be logged in the aircraft records. in addition it only needs to be kept until the action is completed the next time. Fast Eddie's documentation of work performed on the inspection checklist is just as good as your logbook entry in the eyes of the FAA.

[Roger Lee]

I picked the perfect day to be off work. I love these debates. 

 

 

Hi Bob,

 

I agree it's partly a mechanic problem, but how would you know if it is or isn't a problem if he doesn't have it written down what he did. You can't take his word for it because he didn't know he was supposed to do it in the first place.

It's the rule things aren't done not the exception. 

 

p.s.

When we went to court the only guys that got their butts handed to them was the minimal guys and the poor documenters.

 

Hi Tom,

 

I am up on my soapbox partly because I'm just hanging this afternoon, but I'm a huge believer in documentation. Too much time spent in court watching people spiral down the toilet because of minimal documentation.

 

Why not have doctors write IAW protocols instead of specific documentation. Because you have to know what he did, have to know what he did a year from now and have to know if he did it right. How could you hold anyone to medical malpractice if he never documented and or how could he protect himself.  By the way there really are protocols. I used to be an ACLS (advanced cardiac life support)  instructor that taught Docs., medics and nurses.

 

"An inspection is not maintenance. An inspection is an inspection. The regulations tell you that you must do the inspection IAW "in accordance with" whatever documentation is pertinent to the airplane you are working on."

 

You're absolutely right. The problem is most mechanics don't read manuals or look up SB's. It happens every single day. That tends to be a lot more mechanics than most would like to admit to. You can write all the regs you want as to what they are supposed to do, but how do you know they did it without a check list and logbook documentation to show it? How do you hold that mechanic responsible and accountable if you have no idea to what he did.

 

"Also I would like to point out that there is no requirement to put anything in a logbook, but rather it is to be logged in the aircraft records." 

 

This is a minimum standard and what the bottom 10% get to fall back on.  

The FAA says the check list isn't a legal document that carries the same weight as the logbook because check list aren't required and the logbook is.

 

"I agree that in many instances mechanics do not do a good job of making maintenance entries."

 

See we do agree.

 

 I'm not a minimal type personality nor have I ever wanted to say I was at the bottom 10% of my class because I produced minimal work. I would rather be above the average line. To me if all you want to do is minimal work then you just want be average and or below. To me it's all about the pride in your work to strive to be better than minimal or average.

[Roger Lee]

I'm going to go out on a limb here and put myself up for ridicule.

 

Anyone that has been to my shop for an annual/100 hr. inspection speak up if you dislike the paperwork that you received.  Would you like me to stop the Discrepancy List, the Rotax and FD  signed off and side noted check list that you get and instead of a 1 page logbook entry just write a 3 line note that just says IAW.

 

If you want me to stop your all your documentation for the inspections now's the time to speak up?

 

 

 

Eddie,

Would you have been happy with just an IAW for all the work we did on your plane or were you happier to see it in writing?

[Tom Baker]

Roger, you need to stop think that if someone doesn't do it like you they are wrong. From your description you are logging the inspection and any maintenance that was done because of the inspection in the same entry. From a legal standpoint the inspection must be done IAW whatever documentation is appropriate to the airplane being inspected. This is where the required checklist for the inspection comes into play. If you find something wrong then you make a discrepancy list. When you fix an item on the list then you are doing maintenance and it should also be logged. Maintenance items do not need to be logged in the inspection sign off.

[Anticept]

I keep digital records of my inspection checklists and other notes. I don't put them with the aircraft records (waste of paper because it will turn into a thick stack real quick), but they are available on request.

[Roger Lee]

"That's how the system is designed and how it is intended to be followed."

 

Agreed, but:

 

Regs. are only as good as the person that follows them. Look at the attachment and tell me how well IAW met it's objective. This is not a once in a life time case unfortunately. 

 

Now make human beings follow that. We wouldn't need the extra FAR's that everyone dislikes so much because they think they are intrusive if someone didn't try and subvert or do minimal maint. 

If you have ever seen one logbook entry for an annual that was bad then you have your answer and a spec of the tip of the iceberg. The regs may be up to snuff, but some mechanics aren't and we all know that.

 

I'm not bashing any person, I'm just questioning ideas and beliefs. Just my view on minimal documentation and the possible consequences on being minimal. Any mechanic can do what he/she wants, but it could end up owner beware as the 2007 CTSW owners just found out.

 

If we do such a good job as the FAA wants then why would a discrepancy list look like this. Years of neglect and wrong doing. How did the FAR's help this owner. Without any documentation who knew all these issues were outstanding or never addressed.

 

The attachment is only labeled sample to protect owners, but is a real and recent inspection and the previous mechanic said it was done IAW.

Sample.pdf