THE MIRACLE OF FLIGHT
'(<a href="http://www.j-archive.com/media/2005-11-29_DJ_22.jpg" target="_blank">Jimmy of the Clue Crew compares two paper airplanes.</a>)  In paper airplanes, bending the rear section of the wing up or down has the equivalent effect of this device that moves up & down in a jumbo jet's tail'
an elevator