Who owns patent for gyroplane J2 who owns patent for gyroplane Avian Pagasus who owns patent for gyroplane AS 18A who owns patent for gyroplane AirSpace 18A?

I don't know. But the way to find out is www.USPTO.gov. The US Patent and Trademark Office. They allow searches by many criteria. It will take just a little work, but once you know how to search on USPTO, your power will increase.