Can an owner do a compression check?

Old Geek said:
In the course of servicing the spark plugs? Can he log the readings?
Click to expand...

I don't log compression checks between annuals but I don't see why an owner couldn't perform the inspection. I'd make sure you know what to look for. The readings on the gauge tell about 30% of the story IMHO.
 
Be sure you know what you're doing, don't want the pressurized cylinders to send the prop towards your head.
 
Look under FAR Part 43 for a list of what owners/PP can do to their aircraft if you have a certified aircraft, If SLSA its up to the manufacturer to tell you what you can do.
 
CTLSi said:
Look under FAR Part 43 for a list of what owners/PP can do to their aircraft if you have a certified aircraft, If SLSA its up to the manufacturer to tell you what you can do.
Click to expand...

I'm pretty sure that this is not the correct answer.

The AOPA owner maintenance web page lists a zillion inspections that owners can perform, none of which are specifically authorized by Part 43. The issue seems to be whether or not the activity requires non-approved disassembly and reassembly.

Following your train of thought, a owner would not be authorized to perform a visual inspection of the exterior of the aircraft's engine, as it is not specifically authorized by FAR Part 43.
 
Last edited:
It's not one of the 31 items of preventive maintenance a pilot is authorized to do, so I would say it's not something a pilot is permitted to do. But even if you were, you are certainly not authorized to enter it in the aircraft maintenance records since the only things a pilot is allowed to sign there are those 31 items and the VOR check required and authorized by 14 CFR 91.171. As for "a visual inspection of the exterior of the aircraft's engine", if you do it as part of your preflight, that's one thing, but if you log it as an "inspection" in the maintenance records, that's another thing entirely. See 14 CFR Part 43 for who is authorized to sign what in maintenance records.
 
Yeah man. I got the logbooks perched on the step ladder and my trouble light clipped to the prop. One spark plug's removed and my brand new Autozone compression tester is in hand ready to push it in the hole. Now if I can get my ditzy teenager to stop texting long enough to turn the mag switch to start--I won't have to pay a mechanic to do this.

dtuuri
 
Ron Levy said:
It's not one of the 31 items of preventive maintenance a pilot is authorized to do, so I would say it's not something a pilot is permitted to do. But even if you were, you are certainly not authorized to enter it in the aircraft maintenance records since the only things a pilot is allowed to sign there are those 31 items and the VOR check required and authorized by 14 CFR 91.171. As for "a visual inspection of the exterior of the aircraft's engine", if you do it as part of your preflight, that's one thing, but if you log it as an "inspection" in the maintenance records, that's another thing entirely. See 14 CFR Part 43 for who is authorized to sign what in maintenance records.
Click to expand...

Let's assume that it's out of curiosity. And BTW, this is not a theoretical argument. And I have no skin in the game other than finding it an interesting discussion. Would you agree that if an owner pulls out the plugs for preventative maintenance, he could shine a flashlight into the spark plug hole and look around? Just out of curiosity?

Got any case law on borderline owner maintenance issues?
 
Old Geek said:
Let's assume that it's out of curiosity. And BTW, this is not a theoretical argument. And I have no skin in the game other than finding it an interesting discussion. Would you agree that if an owner pulls out the plugs for preventative maintenance, he could shine a flashlight into the spark plug hole and look around? Just out of curiosity?
Click to expand...
Sure. Just don't write it in the engine log as any kind of "inspection" of the engine.

Got any case law on borderline owner maintenance issues?
Click to expand...
Not off the top of my head, and the NTSB O&O site seems to be down at the moment.
 
Old Geek said:
I'm pretty sure that this is not the correct answer.

The AOPA owner maintenance web page lists a zillion inspections that owners can perform, none of which are specifically authorized by Part 43. The issue seems to be whether or not the activity requires non-approved disassembly and reassembly.

Following your train of thought, a owner would not be authorized to perform a visual inspection of the exterior of the aircraft's engine, as it is not specifically authorized by FAR Part 43.
Click to expand...

Not a train of thought. We fly under FAA regulations (FAR), not under anything a trade group comes up with...
 
Ron Levy said:
It's not one of the 31 items of preventive maintenance a pilot is authorized to do, so I would say it's not something a pilot is permitted to do. But even if you were, you are certainly not authorized to enter it in the aircraft maintenance records since the only things a pilot is allowed to sign there are those 31 items and the VOR check required and authorized by 14 CFR 91.171...
Click to expand...

Nonsense. You can do a compression check and you can enter the results in your logbook and sign it. You can enter pretty much anything you want, it is after all your logbook. What you can't do is sign off anything as being deemed airworthy or returned to service. Your compression test results for instance would serve no purpose other than for your own reference. A Mechanic doing an annual isn't going to look at them and forgo doing a compression test because you've already done it.

The only advise I would give is that, if it's the first time you've done a compression test, wear a helmet. ;)
 
Silvaire said:
Nonsense. You can do a compression check and you can enter the results in your logbook and sign it. You can enter pretty much anything you want, it is after all your logbook.
Click to expand...
This from the guy who says an owner can legally alter the licensed empty weight/cg documents over his/her own signature. Before you take Silvaire's advice about what people other than an A&P or CRS can put in an aircraft's records, check with your local FSDO Airworthiness Inspector.
 
So before you write anything in your own logbook you gotta call the local FSDO to find out if it's okay? Are you serious?

BTW - I never said anyone could alter an existing entry or document and you know that so quit making s**t up.
 
Ron Levy said:
This from the guy who says an owner can legally alter the licensed empty weight/cg documents over his/her own signature. Before you take Silvaire's advice about what people other than an A&P or CRS can put in an aircraft's records, check with your local FSDO Airworthiness Inspector.
Click to expand...
Yeah but this time I agree with him :D. In the not too distant past the maintenance logs were co-mingled with usage logs, squawks, and other bits of information unrelated to maintenance and AFaIK there's absolutely nothing wrong with that practice today, it's just less common.

I assume we all agree that it's "legal" for any PPL holder to check the compression of his engine, right?

And if he chooses to write the results in the same document that contains official maintenance records with or without his cert # and signature I can't see how this runs contrary to any sane interpretation of the FARs as long as he's not trying to pass this off as a required "inspection".
 
Show me a regulation that states that I *can't* put an entry in the logbook providing it's factual. I don't believe you can prove that the entry itself is ever a violation of a FAR.
 
Old Geek said:
Show me a regulation that states that I *can't* put an entry in the logbook providing it's factual. I don't believe you can prove that the entry itself is ever a violation of a FAR.
Click to expand...

I'd say your answer is within FAR part 43.

The question I have with this is what is a compression check considered? Maintenance, preventive maintenance, or an inspection? Depending on the answer to this you'd have your answer on who can make the logbook entry.

As far as I'm concerned, legal or not I don't see why an owner couldn't do a compression check. It isn't an invasive process so there is little that could really be damaged as a result. I would however strongly encourage an owner to get help from a qualified individual the first time, otherwise an injury may result.
 
mondtster said:
I'd say your answer is within FAR part 43.

The question I have with this is what is a compression check considered? Maintenance, preventive maintenance, or an inspection? Depending on the answer to this you'd have your answer on who can make the logbook entry.

As far as I'm concerned, legal or not I don't see why an owner couldn't do a compression check. It isn't an invasive process so there is little that could really be damaged as a result. I would however strongly encourage an owner to get help from a qualified individual the first time, otherwise an injury may result.
Click to expand...

Without getting too specific, it's to satisfy a fastidious owner's curiosity. He flies a lot and his engine has well over 1000 hours on it. He wants to be able to track pound per pound any trend of loss of compression. He is still complying with all other normal maintenance procedures.
 
I don't think you understood my last post. It was regarding who can put an entry in the logbook and what the entry should say. FAR 43 has specifics on this.
 
Silvaire said:
So before you write anything in your own logbook you gotta call the local FSDO to find out if it's okay?
Click to expand...
I didn't say that.
Are you serious?
Click to expand...
About calling the FSDO before taking your advice on altering aircraft records or signing for things you're not authorized to do? Yes, I am.

BTW - I never said anyone could alter an existing entry or document and you know that so quit making s**t up.
Click to expand...
Yes, you did, You said a pilot could make changes to the empty weight and balance documents over his own signature. That's alteration of the records a pilot is not authorized to do.
 
gismo said:
I assume we all agree that it's "legal" for any PPL holder to check the compression of his engine, right?

And if he chooses to write the results in the same document that contains official maintenance records with or without his cert # and signature I can't see how this runs contrary to any sane interpretation of the FARs as long as he's not trying to pass this off as a required "inspection".
Click to expand...
I don't agree. But as I said, if you really want to do that, I strongly suggest you check with the FAA before you do. And if they say it's OK, I'd sure like to hear about it.
 
mondtster said:
The question I have with this is what is a compression check considered? Maintenance, preventive maintenance, or an inspection? Depending on the answer to this you'd have your answer on who can make the logbook entry.
Click to expand...
Since it's not one of the 31 items in paragraph (c), Appendix A, Parr 43, it's definitely not preventive maintenance.
 
mondtster said:
I don't think you understood my last post. It was regarding who can put an entry in the logbook and what the entry should say. FAR 43 has specifics on this.
Click to expand...

Show me the specific regulation. I've read them all and they carefully spell out who *must* make *specific* types of entries. I see nothing prohibiting an owner from making a factual entry. The task that the entry refers to must not exceed the owner's privileges, but even if it does, the act of logging it is not, in itself, a violation of the FAR's. Feel free to prove me wrong with an actual regulation.
 
Ron Levy said:
Since it's not one of the 31 items in paragraph (c), Appendix A, Parr 43, it's definitely not preventive maintenance.
Click to expand...

I agree, I'm just curious what some of the mechanics think.

As near as I can tell, I think it might be considered an inspection. It is listed in appendix D, and it really isn't a repair of anything.

So, the question becomes, who can sign off an inspection? :wink2:
 
Old Geek said:
Show me the specific regulation. I've read them all and they carefully spell out who *must* make *specific* types of entries. I see nothing prohibiting an owner from making a factual entry. The task that the entry refers to must not exceed the owner's privileges, but even if it does, the act of logging it is not, in itself, a violation of the FAR's. Feel free to prove me wrong with an actual regulation.
Click to expand...

The question is, who is returning it to service? Or is the consensus that it was never out of service? A pilot/owner can only return to service any preventive maintenance. Legally speaking, I don't feel a compression check falls into that category.

Why are you so insistent that your compression check needs to be documented in the logbook? Does your friend not own a notebook?
 
mondtster said:
The question is, who is returning it to service? Or is the consensus that it was never out of service? A pilot/owner can only return to service any preventive maintenance. Legally speaking, I don't feel a compression check falls into that category.
Click to expand...

In my scenario, the aircraft was taken out of service for preventive spark plug maintenance and returned to service likewise. The compression check was performed as an informal check for the owner's convenience. No additional components of the aircraft were disturbed in any way.

mondtster said:
Why are you so insistent that your compression check needs to be documented in the logbook? Does your friend not own a notebook?
Click to expand...

I'm not sure why this is an issue either, except that it's become an arguing point. An interesting one at that.

I think we can all agree, except maybe Ron, that we'd rather be out flying today, but since we're not, we're here arguing.
 
Ron Levy said:
...You said a pilot could make changes to the empty weight and balance documents over his own signature. That's alteration of the records a pilot is not authorized to do.
Click to expand...

You lost that argument last week. Why do you continue to drag it out again at every opportunity.

Anyone who wants to know what it's about can read the "Who can update W&B records?" thread and draw your own conclusions. I'm not going to get into a public bicker-fest with this nutcase.
 
Old Geek said:
I think we can all agree, except maybe Ron, that we'd rather be out flying today, but since we're not, we're here arguing.
Click to expand...
I flew yesterday. I'll fly every day this coming week. Today I'm watching the race and the O's game.

And I don't agree that your aircraft's maintenance records are "yours" in which to put anything you want. Unlike your pilot logbook, they belong to the airplane, and that airplane may not be yours forever.
 
gismo said:
Yeah but this time I agree with him :D. In the not too distant past the maintenance logs were co-mingled with usage logs, squawks, and other bits of information unrelated to maintenance and AFaIK there's absolutely nothing wrong with that practice today, it's just less common.

I assume we all agree that it's "legal" for any PPL holder to check the compression of his engine, right?

And if he chooses to write the results in the same document that contains official maintenance records with or without his cert # and signature I can't see how this runs contrary to any sane interpretation of the FARs as long as he's not trying to pass this off as a required "inspection".
Click to expand...
I'm with you on this one. My early Flybaby logs are almost like pilot logs in the same book. There is nothing out there to prohibit this.
 
You can log anything that you can get an A&P to "supervise" and sign off on - up to and including a major overhaul.

If it's not logged, it didn't happen.

I do both leakdown and compression tests on my engine at annual time - I find that the compression test will show differences between cylinders that the leakdown does not. The leakdown numbers get logged as part of the "owner assisted" condition inspection, the other numbers are in my notebook.
 
Capt. Geoffrey Thorpe said:
You can do anything that you can get an A&P to "supervise" and sign off on - up to and including a major overhaul.
Click to expand...
Entirely true for maintenance and alterations.

If it's not logged, it didn't happen.
Click to expand...
I agree. If you're going to do this, don't put it in the aircraft's maintenance records.

I do both leakdown and compression tests on my engine at annual time - I find that the compression test will show differences between cylinders that the leakdown does not. The leakdown numbers get logged as part of the "owner assisted" condition inspection, the other numbers are in my notebook.
Click to expand...
Unlike maintenance and alterations, there is nothing authorizing an IA to delegate the performance of any required part of an annual inspection. I suppose you can do the compression test for the annual, but the IA has to be watching the gauge and what you do.
 
Ron Levy said:
And I don't agree that your aircraft's maintenance records are "yours" in which to put anything you want. Unlike your pilot logbook, they belong to the airplane, and that airplane may not be yours forever.
Click to expand...

Are we talking about agreeing in principle or the interpretation of the FAR's. I will certainly allow your disagreement in principle. But I don't see it in the FAR's.
 
You guys give me a headache.

Yes, you can do a compression check on your own plane, I've flown 3,000+ hours and owned a dozen planes. I have never had anyone BUT me do a compression check and used those numbers in the condition inspection.

Maybe this is another good reason why I only fly experimentals. Do you have any idea how silly it sounds to me to NOT be able to work on your own plane? :dunno:

I am offended! :lol:
 
Last edited:
Geico266 said:
Yes, you can do a compression check on your own plane, I've flown 3,000+ hours and owned a dozen planes. I have never had anyone BUT me do a compression check and used those numbers in the condition inspection.
Click to expand...
If you have the repairman ticket, you can your own condition inspection on an E-AB. But that's not what we're talking about.
 
I do, every oil change. It's quick and easy since the plugs are coming out anyway.
 
JHW said:
I do, every oil change. It's quick and easy since the plugs are coming out anyway.
Click to expand...

Ok, one cylinder is 50/80. Do you have the authority to log it and return it to service when you're done gapping the plugs?

dtuuri
 
One more thought - if you want to do the leakdown check every month - hey, it's your time. But for logging it - One thing I want to know when buying an airplane (or...) is why it is on the block. If I saw leakdown after leakdown after leakdown beyond "typical" maintenance intervals I would be thinking "someone thinks there is a problem with this engine".
 
bartmc said:
Yes he does.
Click to expand...

Alright, then he signs it off and rents it to a customer who loses the very same jug on takeoff. Who's responsible for the accident, the engine manufacturer or the owner?

Really, I can't see why this is even under debate. In the first place, who the heck wants to record something that has nothing but a downside potential and isn't required by law? :dunno:

dtuuri
 
You must log in or register to reply here.
Back
Top