This report documents research on the Medium Altitude Endurance (MAE) Unmanned Aerial Vehicle ACTD program (also known as the Predator UAV). What were the overarching lessons learned from the Predator ACTD, and which lessons can be generalized and applied to other ACTD programs? The authors detail the Predator ACTD and also document the important demonstration and transition issues from the project that can be applied to other ACTDs.