Building a plane is hard. We found out the hard way.
Our AmadorUAVs team met on a sunny Sunday morning to build our first plane prototype, Calix-0. We had an ambitious goal: Finish building our prototype in just 4 hours. While the software team was busy finalizing the software stack and configuring Ardupilot, the electromechanical division was hard at work building the actual plane, cutting up foamboard and applying generous amounts of hot glue to complete the plane in time.
As time dragged on and the deadline ticked ever closer, we had to speed up our production process. This meant cutting a few corners (figuratively as well as literally). Measurements were eyeballed instead of measured. Pieces of foamboard were haphazardly glued together. The ailerons were immobilized with duct tape, because who needs ailerons, right?
About half an hour before the deadline, the plane’s foamboard body was more or less done, and we began wiring up the radio controller to the servos that controlled the rudder and elevators (no ailerons, remember). Finally, we tossed in the battery, hooked everything together, and went to the park to test fly the plane.
Finally, we were ready. One of us, holding the plane, took off at a run while another pushed the throttle up to 100%. In an exhilarating moment, the plane took off.
Now is probably not a good time to mention that the VERY HEAVY lithium polymer battery was not secured inside the plane.
As the plane tilted back and took off, the battery quickly started sliding to the back of the plane, causing it to flip midair and come screaming back toward us and veer into a nearby tree. Luckily, nobody was hurt and the expensive equipment was safe, but the fuselage was a goner.
TL;DR: Secure your stuff inside the plane before you fly it! Also, maintaining a proper center of gravity is crucial for flight.