Flapping is for the birds, honestly. It's hard to make flapping efficient for all but very light and slow flight. At least as far as man made stuff goes. Nature does it so much better. There are some people who make flapping paper airplanes though - very cool.
Swirls are bad energy suckers.
I sail a little boat on my granpa's beach but it has a centerboard. All the time. It flew straight. I sail a little boat on my granpa's beach but it has a centerboard. Here's my question for you.