This paper describes the design, development, and operation of research Unmanned Aerial Vehicles (UAVs) that have been developed at the Georgia Institute of Technology in the Schools of Aerospace and Electrical/Computer Engineering. This includes a description of flight test experiences and lessons learned over the past 10 years, with emphasis on recent work. Specifically in 1998, Georgia Tech acquired a Yamaha R-Max Remotely Piloted Helicopter (RPH) for use in the DARPA Software Enabled Control and other research programs. An open system UAV testbed was developed based on this vehicle that is referred to as the GTMax. The use of a variety of simulation configurations has been of considerable benefit. Flexible data communication systems, models for all hardware components, and a flexible simulation software infrastructure are important. The use of a modular avionics architecture and the use of a vehicle with a relatively large payload capacity also allow these UAVs to be configured quickly for a variety of experiments.