Originally Posted by
Dana
Put numbers on your plane and:
You need a pilot certificate, with category and class ratings or endorsements appropriate to the aircraft type.
You need a biennial flight review.
You need a yearly condition inspection.
You're subject to all of Part 91, including 91.119 (minimum altitudes).
You have to notify the FAA and do testing in a limited area if you make any major modifications to the plane.
If you flunk a medical exam you can't fly, even as a sport pilot.
Now don't get me wrong, there are advantages to flying a registered plane, too, and I am again, after flying ultralights for 10 years. But there are disadvantages, too.