My paper airplane did this for about 20 seconds can some one sciencey explain? (video included)?

a href="http://www.collegehumor.com/video/5806852/physics-defying-paper-airplane-trick" rel="nofollow"http://www.collegehumor.com/video/580685…/a i threw a paper airplane off the deck of my house and it was doing the thing in the video for 20 second. the only difference is there were no fans around. what would cause something like this to happen in nature?