Can an owner do a compression check?

In the US Airline Mechanics all went to "Aviation Maintenance Technician" or AMT which sounds like some kind of sink cleaning product if you ask me. I'm not sure when or why the title "Mechanic" got a bad rap, maybe because of Lowell on the TV show "Wings" LoL :rolleyes:
 
So, I can legally remove, replace, and reinstall a tire, and can clean and repack wheel bearings. But I CANNOT do a simple compression check, which, in my opinion is a MUCH simpler operation.

Not that there is any logic with the FAA, but where is the logic in that?
 
Rules don't need logic. That's why they are written down.
 
So, I can legally remove, replace, and reinstall a tire, and can clean and repack wheel bearings. But I CANNOT do a simple compression check, which, in my opinion is a MUCH simpler operation.

Not that there is any logic with the FAA, but where is the logic in that?

There is none because it's not true.
 
I'm about to shock you. A very large portion of the GA fleet is just that, owners with their tool box out in the hangar working away on their airplanes. They either find an A&P to sign it off or they do the work and don't say (or log) anything.

And that's the reason I told one customer (whose work was good BTW) I would no longer be signing his annual.
 
And the FAA inspector I asked today. He looked at me and laughed when I asked and told him why. He said "Of course you can."

"Can what?" "Return it to service after logging a low reading?" Bet you didn't ask him that. BTW, asked an "Airworthiness Inspector" or just an "Operations Inspector"?

dtuuri
 
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Asked him if you could do a compression check.

The OP wants to know if the readings can be logged, which raises the issue of "returning to service" which I'm sure is not within the expertise of the typical pilot to determine under "preventive maintenance" privileges. As for just "doing" one, since it isn't listed as preventive maintenance it probably will become an issue when somebody finds a way to muck it up and the FAA discovers it as a result of an investigation. That doesn't make it "allowed". As long as pilots don't damage anything and cause an accident or illegaly return an unairwothy airplane to service, though, the FAA won't know or care.

dtuuri
 
"Can what?" "Return it to service after logging a low reading?" Bet you didn't ask him that. BTW, asked an "Airworthiness Inspector" or just an "Operations Inspector"?

dtuuri

BTW, I know it's a Levy line that Operations Inspectors cannot comment on maintenance or that AW Inspectors can't comment on flight operations but......

It's not true.

You'd be surprised how many Inspectors (operations) hold A&P or A&P/IA certs or are very knowledgeable in both fields.

And of course your comment about returning to service after "logging a low reading" is a bit misleading. If an A&P cannot return to service after logging a low reading, then why would a PP attempt to do so?

We're back to picking flysh*t out of pepper. And we're trying to do it with boxing gloves no less. :rolleyes:
 
We're back to picking flysh*t out of pepper. And we're trying to do it with boxing gloves no less. :rolleyes:

I'm a newbie on this board, but that seems to be a common theme around here!
 
BTW, I know it's a Levy line that Operations Inspectors cannot comment on maintenance or that AW Inspectors can't comment on flight operations but......
I speak for myself.

And of course your comment about returning to service after "logging a low reading" is a bit misleading. If an A&P cannot return to service after logging a low reading, then why would a PP attempt to do so?
It isn't misleading because an A&P is supposed to know when it's too low--and why. That's not something a pilot is charged with determining, so can't make a knowledgeable determination. For all you know, the OP rents planes to students and wants to gap the plugs and log the compressions. That means making airworthiness decisions far beyond just gapping plugs, IMO.

dtuuri
 
For all you know, the OP rents planes to students and wants to gap the plugs and log the compressions. That means making airworthiness decisions far beyond just gapping plugs, IMO.
dtuuri

OP here. Firstly, let me repeat the reason for the question. A friend of mine, who flies a lot, wants to carefully monitor the compression trends of his 1500 hour engine. He wants to see the trends with data points closer than each annual. He's a bit on the fastidious side, but still a responsible, knowledgeable pilot. He also feels that the readings belong in the engine logbook. I advised him to enter them with the disclaimer "for reference only". He will probably not put them in the log because of all the gnashing of teeth from people that view the logbook as some sort of sacred document.

Secondly, how in the world does "log the compressions" = "making airworthiness decisions"? The act of logging the readings is *not* an airworthiness decision. It's an act of writing down data in a book. Data that he fully expects to show a trend that will never be close to an airworthiness decision between annual inspections. But just suppose it *does* reveal an unsafe drop in compression before annual and he grounds the plane until an A&P can look at it? If that's the "airworthiness decision" you're referring to, I'd like to know the downside and/or illegality to it?

In any case, I've heard enough. :mad2:
 
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OP here. Firstly, let me repeat the reason for the question. A friend of mine, who flies a lot, wants to carefully monitor the compression trends of his 1500 hour engine.
Ok, so maybe you or your friend don't rent. It doesn't change my point.

Secondly, how in the world does "log the compressions" = "making airworthiness decisions"?
You/your "friend" need to sign off your work, i.e., return to service after gapping the plugs. Determining unairworthy spark plug gaps are preventive maintenance you can sign off, determining unairworthy cylinders by means of a compression check are not.

He will probably not put them in the log because of all the gnashing of teeth from people that view the logbook as some sort of sacred document.
It's a compliance document. Its proof of compliance. There's no requirement for a compression check during spark plug maintenance by a pilot. Doing so places him unnecessarily at risk. Now, maybe there should be a requirement to do a compression check? How would AOPA stand on that I wonder? If a pilot says he did it, but the engine then fails--would the pilot lose his pilot's license? Or just his spark plug privileges?

...I'd like to know the downside and/or illegality to it?

In any case, I've heard enough. :mad2:
Oh yeah? You're mad huh? Well, I can't believe somebody asks a question, then gets mad at the answer. If all you want is "agreement" what are you doing posting here? And why can't your "friend" ask for himself, what are you, his marketing agent? Frankly, I can't see why ANYBODY disagrees with me on this point, much less RotorandWing. I think he's been watching too many movies. :wink2:

dtuuri
 
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Oh yeah? You're mad huh? Well, I can't believe somebody asks a question, then gets mad at the answer. If all you want is "agreement" what are you doing posting here? And why can't your "friend" ask for himself, what are you, his marketing agent? Frankly, I can't see why ANYBODY disagrees with me on this point, much less RotorandWing. I think he's been watching too many movies. :wink2:

dtuuri

OK, I'm not done.

Yes, I asked a question. I got reasoned explanations why it would be legal and rhetoric and hand-waving as to why it would be illegal. 6 pages in all. And yes, my mind is made up now, mostly because of posts made by people I've learned to respect.

"Everything which is not forbidden is allowed"
http://en.wikipedia.org/wiki/Everything_which_is_not_forbidden_is_allowed

Let's try to keep it that way.
 
...There's no requirement for a compression check during spark plug maintenance by a pilot. Doing so places him unnecessarily at risk...

I'm having a difficult time fathoming the perceived logic of this statement. You are saying that if there is a bad cylinder the pilot is better off not knowing about it.
 
I'm having a difficult time fathoming the perceived logic of this statement. You are saying that if there is a bad cylinder the pilot is better off not knowing about it.
Not what I was trying to say. You lifted me out of context:


It's a compliance document. Its proof of compliance. There's no requirement for a compression check during spark plug maintenance by a pilot. Doing so places him unnecessarily at risk.
I was referring to the logbook entry. Like I said before, up-thread, until somebody figures out how to botch a compression check so badly it hurts somebody and the FAA investigates it, they won't care. But recording readings you made and then signing off the logbooks returns the airplane to service, leaving the pilot exposed should something fail. Why put anything in there in the first place (other than the gapping). Just check it and call a mechanic if it looks suspicious, don't put your name to it. That's what I'm trying to say.

dtuuri
 
...But recording readings you made and then signing off the logbooks returns the airplane to service, leaving the pilot exposed should something fail...

Are you a lawyer or something? I mean seriously, people lay awake at night dreaming stuff like this up to worry about? :rolleyes:
 
Are you a lawyer or something? I mean seriously, people lay awake at night dreaming stuff like this up to worry about? :rolleyes:

I'm no lawyer, but anybody taking your advice should be sure to have a good one.

dtuuri
 
Are you a lawyer or something? I mean seriously, people lay awake at night dreaming stuff like this up to worry about? :rolleyes:

No, the prick is a former "professional Pilot' according to his bio, and a Pilot Examiner. I cannot find him as a DPE so that may or may not be true.

What we have here is some jerknose who was a "professional pilot" and $#it all over the folks who were maintaining his aircraft, just like most of those of his genre.

Jim
Professional pilot and professional mechanic all rolled into one
 
No, the prick is a former "professional Pilot' according to his bio, and a Pilot Examiner. I cannot find him as a DPE so that may or may not be true.

What we have here is some jerknose who was a "professional pilot" and $#it all over the folks who were maintaining his aircraft, just like most of those of his genre.

Jim
Professional pilot and professional mechanic all rolled into one

You aren't "Weird", Jim, you're obnoxious. Here's some reading for you too:
Personal attacks are prohibited. This specifically means any text/post that is blatantly attacking another person on or off the forum, especially in a personal way.​
But I'm glad to know your prejudices, in case anyone I know is thinking of doing business with you. Got any more vitriol to vomit on these pages?

dtuuri
 
Personal attacks are prohibited. This specifically means any text/post that is blatantly attacking another person on or off the forum, especially in a personal way.

I'm no lawyer, but anybody taking your advice should be sure to have a good one.

You're right Jim, he is a jerk. ;)
 
I still don't understand why you would track compressions in the log book.:dunno: I used to just keep a pocket note pad to record all that stuff, makes it much simpler to view the trends.
 
Can you put your finger over the spark plug hole/move prop to check compression. Or do you need a note from the adjutant general counsel for that?
 
Can you put your finger over the spark plug hole/move prop to check compression. Or do you need a note from the adjutant general counsel for that?

For all intents of checking compression one doesn't even have to pull the plugs or cowl except to get a baseline. After that one can just attach a pull scale to the prop at a specific and constant location and pull it through 4 compressions and compare the force required vs last time as well as the other cylinders.
 
I still don't understand why you would track compressions in the log book.:dunno:

I don't think we've been discussing the "why" of it, just that fact that if you so desire, you most certainly can do it. Some people like to keep their pencils in a straight row. Hell, maybe they have to keep them in a straight row. Maybe it's a compulsive disorder of some sort but there's no rule saying they can't do that and doing so isn't setting them up for some ludicrously conceived lawsuit dreamt up by some uber-paranoid misfit.

...and whoever thinks I'm talking about them, don't flatter yourself, I'm not :rolleyes: LoL
 
For all intents of checking compression one doesn't even have to pull the plugs or cowl except to get a baseline. After that one can just attach a pull scale to the prop at a specific and constant location and pull it through 4 compressions and compare the force required vs last time as well as the other cylinders.

I can easily feel a compression issue on my A75 when I prop start it. That said, I just bought a tester so I can get numbers at each oil change.
 
Just reading this thread makes me happy I don't have to own a plane or buy one. I will just keep renting. Sounds like the planes I could afford who knows what kind of monkey has been wrenching on it. I just shudder to think of buying a plane that has been "maintained" by some of the posters on this thread!
 
Just reading this thread makes me happy I don't have to own a plane or buy one. I will just keep renting. Sounds like the planes I could afford who knows what kind of monkey has been wrenching on it. I just shudder to think of buying a plane that has been "maintained" by some of the posters on this thread!

Unless you're planning to fly a lot, you're better off renting anyway.
 
Just reading this thread makes me happy I don't have to own a plane or buy one. I will just keep renting. Sounds like the planes I could afford who knows what kind of monkey has been wrenching on it. I just shudder to think of buying a plane that has been "maintained" by some of the posters on this thread!

lol, and how exactly is renting a solution for your over-the-top irrational fears?
 
lol, and how exactly is renting a solution for your over-the-top irrational fears?

:rofl: No need to scare him with the reality of incompetent and even pencil whipping fraudulent shops out there.
 
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