http://en.wikipedia.org/wiki/File:Oemichen2.jpg	1920 - Oemichen No. 2 Had 4 rotors and 8 propellers all driven by one motor Over 1000 Successful flights First recorded FAI distance record of 360m in 1924 for a helicopter Very Stable for the Time Designed by Etienne Oemichen US Air force Project
http://www.aviastar.org/helicopters_eng/convertawings.php	1956 - Convertawings Model A Quadcopter Designed by Dr. George de Bothezat and Ivan Jerome One of the first quadcopters to use varying thrust of the four propellers in order to control roll, pitch, and yaw. Was very hard for the pilot to fly because of the workload of trying to control the thrust of all four props at once.
http://www.aviastar.org/helicopters_eng/curtiss_vz-7.php	1958 - Curtis Wright VZ-7 Designed by Curtis Wright company US Army Project Used variable thrust in the four propellers to control flight
http://www.flyingcameras.ca/blog/the-rapid-rise-of-the-multicopter-and-the-dji-phantom/ http://design-engine.com/parrot-ar-drone-2-0-quadricopter/	Current Developments In the past 10 years many small quadcopters have entered the market that include the DJI Phantom and Parrot AR Drone. This new breed of quadcopters are cheap, lightweight, and use advanced electronics to for flight control.