Leon wrote:

Than is good for both if both use it equally. My friend co-owned an
airplane in the early to late mid 80's. His partner flew the plane much
more than he did. Seemed my friend was spending a lot of money and not
flying so much although he was going out for 3 or 4 hours weekly at a
minimum. He ended up selling his half and purchasing another all by
himself.

That can happen if the partership isn't set up well. My partner does
fly about 60-80 hours a year more than I do, as he's 5 minutes from the
airport, and he does 2-3 Connecticut to Texas trips each year. Part of
our agreement includes him paying for the storage, as I drive farther.

We bill EVERYTHING hourly, so I don't care.

This includes an engine rebuild and major maintenance reserve,
insurance, taxes, etc... Also, the longer the trip, the better the fuel
mileage, as the airplane spends a lot more time fully leaned out at
altitude. About the worst consumer of fuel per hour is touch and
recurrent check rides.

We knew each other before the plane, and both of us have been in
business partnerships. We sat down and pre-determined every possible
way we could part ways, and set the resolutions to paper in a legal
document. Lots of people don't want to do this, but it's really
important. If you can't deal with bad endings up front, they'll be
worse down the road. Our agreement covers everything from one of us
destroying the aircraft, and dying in the process, to one of us not
being able to make a payment, to divorce, to forced relocation.

My plane partner is also a partner in a very successful bicycle shop,
and he owns a boat in a partnership with another guy.

The bottom line are the people involved and the willingness to get by
all the possible negative outcomes up front.