I don't know about un airworthy. I personally didn't consider it unsafe, just entertaining, but then again, my background was modelflying, with all kinds of lopsided things. I was prepared for the wing drop by its manners when lifting off, and almost kept the wing from dropping, with a large dose of rudder, much to the amazement of my instructor, who had asked to have just this plane, since we were going stalling, and who before the first stall, had asked me to just make a nice, straight stall.