For those who have an aircraft owned and operated solely by their single member LLC (the LLC pays for all expenses, and you're the only one flying it), how do you avoid being classified as a "flight department company" and operating 'illegally'? Is the FAA going after GA on this?
I'm also not a lawyer, but this seems to be the right answer. In addition to the usual good advice of "ask a lawyer if an LLC in general and the LLC structure you're envisioning in particular is a good idea," the difference between most private pilot plane ownership LLCs and the "flight department company trap" LLCs is
operation.
Private pilots who have a plane ownership LLC are usually doing it because there are multiple pilots who share the plane. (You could just as easily do it as a single member, but it wouldn't protect you from much.) The LLC owns the plane, leases it under whatever terms (wet, dry, whatever) to member pilots, and then the pilots themselves are
operating the flights. That doesn't protect you from much if you crash into somebody's house -- you were operating the flight and piloting the airplane as a private person. But it does give you a little bit of protection if one of your partners flies into somebody's house -- they can't say "you own the plane with him; why would you let him fly on a day when the weather was this bad?" because you don't own the plane, the LLC does. And it might give you protection if the plane blows up in your hangar and damages someone else's plane, etc.
When the LLC also
operates the flights -- usually by hiring the pilots and owning the plane in a "flight department company", but you might also run into this issue as a private person if you tried to hire a * flight instructor through the LLC instead of on your own dime -- then it's suddenly operating flights for compensation, which comes with its own requirements. In that case, the "compensation" can be as little as "you paid the LLC for the gas you burned" or "you paid the LLC for the flight instructor" or whatever.
So I think the most direct answer to your question is that the LLC owning the plane is fine, and common, though doesn't protect you from much if you're the only one involved (may still be a good idea if you envision partners some day, or worry your plane might blow up in the hangar or whatever, but ask a lawyer). The problem arises when that LLC is also "providing" a pilot or operational control in one way or another.
* EDIT: Removed "ferry pilot", as I agree with wilke, the issue is flying with a passenger or cargo for the good of someone other than "the LLC" as an organization. If the plane just needs to get from point A to point B with no passengers/cargo, a ferry pilot is probably fine.