Small Unmanned Air Vehicle Achieves Record Flight Time Using Hybrid Fuel Cell/Battery Energy Storage System Published Jan. 4, 2008 By Propulsion Directorate AFRL/PR WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- AFRL engineers, in conjunction with Small Business Innovation Research partners AeroVironment (AV), Protonex Technology (PTX) Corporation, and Millennium Cell (MCEL), successfully flight-demonstrated Puma, AV's hand-launched small unmanned air vehicle (SUAV) that gets its power from a hybrid fuel cell/battery energy storage system. Puma flew for 7+ continuous hours on power supplied by PTX Corporation's PTX.L fuel cell system. The hybridized proton exchange membrane fuel cell employs a lithium ion battery to provide peak power during takeoff and dash maneuvers; the fuel cell recharges the battery and provides continuous steady-state power for the plane and payload during cruise flight. MCEL provided a fuel cartridge of sodium borohydride (chemical hydride), which provided the fuel necessary for the fuel cell system's 7-hour, 3-minute flight. The duration of Puma's flight represents a substantial increase in flight time for this class of SUAV. The standard Puma has a flight time of 2.5 hours on rechargeable batteries, while other electric SUAVs used by the military have flight times ranging from 45 minutes to 1.5 hours. The Puma SUAV delivers advanced flexibility and endurance, with an adaptable design that permits the addition of custom payloads in lieu of the air vehicle's standard configuration of color and infrared cameras. In addition to being easy to deploy and use, Puma allows operators to view both stationary targets and moving targets. The platform provides real-time intelligence via persistent low-altitude reconnaissance with a low noise signature. The hand-launched Puma weighed 14 lbs, including its onboard fuel cell system and single onboard camera. Future flight demonstrations will seek to extend the plane's flight time, reduce its weight, and provide room for a full payload.