Am am the new owner of an old airplane. I am also a low-time pilot, so I don't have the years of experience about these things that others may have--hence my questions.
I think the previous owner did some things that I would like to undo. What I have noticed is that pilot/owners will say "I put a new radio in", which translates to "I had an avionics shop install a radio in my plane". I saw two pilot/owners replace an exhaust system on an engine in a guy's hangar, neither was an A&P. Was I supposed to report that? How did they "get away" with doing it? It is difficult to tell who does what unless you witness it.
So, let's say I pull my panel off, make some wiring changes and put it back. Who is to know I did this?
This is what I do not understand. I think the previous owner made electrical changes that were not logged in any way. What is to keep me from undoing those things. Is it "forbidden" for the pilot/owner to remove the instrument panel? Where is the line drawn when it comes to maintenance? Please don't quote the FAA reg as I have read it.
I am not trying to save money or tamper with my safety, but as an engineer, very little about my airplane is rocket science to me. The parts I do not understand or have the tools or patience to deal with I am happy to leave to others and pay them fairly for what they do.
Please PM if anonymity is desired.
Unfortunately, "undoing" an improperly made modification by yourself is just as illegal as the mod was in the first place. Like others have said, you need to find an A&P (in some cases you'll need one with an IA as well) that will work with you and sign things off.
I'm wondering what it is about the "mods" made by the previous owner that you're uncomfortable with. Is it the quality of the work (unapproved wire, connectors, crimps, inadequate labels, etc), the design and/or function of the changes (insufficient overcurrent protection, non-standard mod, etc), or just the "illegality" of it that you are concerned with?
I'm an engineer too and frequently participate in the modification and repair of my airplanes but I do this with the assistance of a few qualified techs to keep it legal (and safe). On mechanical issues that I haven't dealt with before I'll seek the knowledge required to do it correctly from a trusted A&P, usually by having him work with me directly the first time. For electrical issues I almost always do a fair amount of the diagnosis by myself since I've found that I'm usually more capable of that than most certified mechanics, but when it comes to the "fix" I'll do the work under the supervison of an A&P (who then signs off the repair in the logs) even though I probably understand the problem better than the mechanic. And I've found that once they get to know me, the good mechanics have no problem with that (a rare few will have ego issues).
As to the "turning in" of other owners doing their own work, I'd stay well away from that unless you're certain there's a significant safety risk to you or others besides the owner. For one thing, you probably have no way of knowing that the work isn't being supervised (loosely) by a certified mechanic. And for the most part I'd say what they are doing is their own business whether perfectly kosher or not. You certainly aren't obligated to police the airport for such "evildoers" and I think that most other pilot/owners would not take kindly to you're attempts to fulfill that role.
Are you well versed in what pilot/owners are legally allowed to do in the way of "preventative maintenance"? You can find a copy of FAR 23 appendix A which spells this out fairly clearly. You should also know that when a pilot does this kind of work he is also required to sign off on the work in the logs.
I'd also like to point out that many shops and/or mechanics will often perform some repair without making a log entry, especially when the result is an airplane that's restored to the exact same condition as it was before the problem repaired occurred, e.g. tightening a loose clamp or replacing a missing fastener or a failed circuit breaker. Since most parts aren't serialized and most part 91 piston powered airplanes never undergo much scrutiny this kind of thing rarely has any negative consequences whether done by a certified mechanic or a savvy owner. I've also seen some horriblly implemented electrical work by certified mechanics that should know better. I once owned a Bonanza I purchased from an owner who had an A&P certificate. He had installed several items that were wired with rubber insulated "lampcord" and had made connections by twisting wires together and covering the splice with electrical tape (at least he didn't use masking tape!). The mechanical work he'd done was considerably better but even there I found a (very) few items that had me shaking my head in wonder.
For reasons I've never fully understood, it's quite legal for a private pilot with no mechanical experience or ability to change the oil, replace spark plugs, fuel lines, or remove and install any non-structural components of the airplanes to name a few items. IMO it would make a lot more sense if the regs required a signoff by a certified mechanic in the pilot's logbook stating that the pilot has the knowledge required to perform each specific task or type of work, in some cases restricted to a particular make/model of aircraft. And I believe that the kinds tasks that a pilot could be allowed to do and sign off independently could be expanded well beyond the current set in part 23. Unfortunately (or fortunately perhaps) I'm not running things at the FAA.
