This paper summarizes the design and systems integration for a PEM (Proton Exchange Membrane) fuel cell powered UAV, expected to break the world endurance record in the radio controlled category as set by the FAI (Federation Aeronautique Internationale). This project is being developed by CSULA (California State University Los Angeles), in conjunction with OSU (Oklahoma State University) and HFC (Horizon Fuel Cell Technologies). The UAV is powered by a 150 Watt PEM fuel cell and a 4-cell 2100 mah lithium polymer battery. An all composite aircraft, it weighs 5 kg, has a wing span of 4 m, and is 2 m long. This UAV has already set a 76-mile range record during a recent test flight. An endurance attempt is tentatively scheduled for June 2008. The endurance record to be broken is in the F5 COMB category (radio controlled aeroplane class powered by any single or combined sources of current), as set by FAI.