Unairworthy Paperwork?

[Witmo]

As Jim pointed out the answers are YES and NO.

The owner can perform his own compression test, he can even make a logbook entry stating so and what the results were.

Other than under the direct supervision of an a&p, is it really legal for a pilot to do a compression check and log it in the MX record? What part of preventive MX would compression testing fall under?

 

[Silvaire]

Other than under the direct supervision of an a&p, is it really legal for a pilot to do a compression check and log it in the MX record? What part of preventive MX would compression testing fall under?

Yes, FAR 43 Appendix A Paragraph C Item (20) allows you to clean and gap spark plugs. Doing a compression test at that time is not going to violate any rules. As far as the maintenance log entry, it is your logbook after all and you can log putting air in your tires if you so desire. In the old days, back in the late 40's and 50's aircraft logbooks were much more owner oriented and you will often see that every flight, every quart of oil and gallon of fuel added was entered in the logbook.

 

[Henning]

My original logbooks are set up,to be flight logs.

 

[Witmo]

Yes, FAR 43 Appendix A Paragraph C Item (20) allows you to clean and gap spark plugs. Doing a compression test at that time is not going to violate any rules. As far as the maintenance log entry, it is your logbook after all and you can log putting air in your tires if you so desire. In the old days, back in the late 40's and 50's aircraft logbooks were much more owner oriented and you will often see that every flight, every quart of oil and gallon of fuel added was entered in the logbook.

So now you're saying that as long as you're doing something you are authorized to do like cleaning spark plugs, you can do anything else? Ridiculous. Show me where doing a compression check without supervision is preventive mx.

 

[Henning]

So now you're saying that as long as you're doing something you are authorized to do like cleaning spark plugs, you can do anything else? Ridiculous. Show me where doing a compression check without supervision is preventive mx.

No sir other way around, show where it is excluded. Even administrative law is inclusionary. You think you can get dinged for pulling a compression test on your own plane when the only wrench turning is expressly a listed item? You are off your rocker.

 

[Silvaire]

You've completely lost me pal. What exactly is doing a compression test supposed to "prevent"?

No, on second thought just forget it. You win through attrition

 

[Greg Bockelman]

Compression checks are NOT rocket science. In fact, other than plugging in the fitting into the spark plug hole, absolutely NOTHING is being done to the engine.

They aren't something I would want someone to do who has never done them before, but really, there is no reason why a non A&P shouldn't do them.

If people get uptight about putting the values in the logbook, then record them on a separate piece of paper.

 

[Henning]

At pretty much any repair station, I bet you have a 50/50 chance that the person doing your compression check (and even cylinder swap) doesn't have an A&P.

 

[poadeleted20]

At pretty much any repair station, I bet you have a 50/50 chance that the person doing your compression check (and even cylinder swap) doesn't have an A&P.

But if not, that person must have been trained and certified IAW Part 145 to do that task for that shop to be operating legally, and is not authorized to do it outside that shop.

 

[acrophile]

We've been talking about a situation with three variables, two of which are known to be correct but due to a mathematical error the third, derived value, is incorrect.

Wait, how is that known? How did you ascertain that the mechanic entered the component values correctly but entered the wrong value for the total, rather than entering the total correctly and entering one (or more) of the component values incorrectly?

The laws of arithmetic guarantee that the mechanic made a mistake, but they don't guarantee which mistake the mechanic made.

 

[Silvaire]

Wait, how is that known? How did you ascertain that the mechanic entered the component values correctly but entered the wrong value for the total, rather than entering the total correctly and entering one (or more) of the component values incorrectly?

The laws of arithmetic guarantee that the mechanic made a mistake, but they don't guarantee which mistake the mechanic made.

The mathematical error is evident, it's right there staring you in the face. There is no evidence that anything else was entered in error but if you want to begin suspecting everyone in the room that would be a different discussion, not the one we are currently having.

 

[acrophile]

The mathematical error is evident, it's right there staring you in the face. There is no evidence that anything else was entered in error but if you want to begin suspecting everyone in the room that would be a different discussion, not the one we are currently having.

No, the evident mathematical error consists of the inconsistency between the total and the individual components. Just from examining the numbers, we know that at least one of the numbers must be wrong. It could certainly be that the total is the one that's wrong, but as far as I can tell that's just a guess you're making. Alternatively, the total could be correct, but at least one of the individual component numbers could instead be wrong.

Perhaps you're guessing that the mechanic entered each component number in the logbook and then, looking and those entries, computed the total. In that case, yes, it's most likely the total that's wrong.

But what if the mechanic recorded and computed everything on scratch paper, and then copied the numbers to the logbook? In that case, the error could have arisen anywhere.

 

[Silvaire]

No, the evident mathematical error consists of the inconsistency between the total and the individual components..

I have absolutely no idea what you are talking about. Two components were measured, the third was calculated from the those. There was an error in the math.

You seem to want to introduce the concept that maybe the measurements were wrong despite having no evidence to substantiate that. But even if they were wrong there would still be the mathematical error which we have evidence of and know to be true.

I think you need to start your own thread because you are talking about a completely different ballgame than what we have going on here. After all it is conceivably possible that the Mechanic may be an impostor who stole someone's wallet. Identity theft is, after all, the fastest growing crime in America although if some poor sap were to steal mine I'd just hope he has better luck with it than I've had

 

[Silvaire]

...But what if the mechanic recorded and computed everything on scratch paper, and then copied the numbers to the logbook? In that case, the error could have arisen anywhere.

Okay sorry, I see now what you are saying. Well in this unique situation the mathematical error was not a random number, it was the result of performing an incorrect function. In other words, the result was correct for that function but that is not the correct answer to the problem.

 

[acrophile]

I don't see why you say the situation is "unique". Surely this sort of thing has occurred more than once in the history of the world.

In any case, you see now how the total could in fact be correct. So a pilot who undertakes to "correct" the total, without consulting the mechanic who signed off on it, is making a guess that could well be wrong.