Aerovironment's Puma unmanned air vehicle has flown continuously for over 7h using the US fuell cell company Protonex's ProCore UAV system.
The US Air Force Research Laboratory UAV development project already achieved a 5h endurance in June last year with a Protonex powered Puma, which has a wingspan of 2.59m (8.5ft), is hand-launched, has a rechargeable battery powered flight time of 2.5h, can fly autonomously and uses satellite navigation. It provides aerial observation at line-of-sight ranges up to 10km (5.4nm).
The ProCore UAV propulsion system is a fuel cell that couples stack technology that can achieve 1,000W/kg (454W/lb) power output with a chemical hydride for storing its hydrogen fuel.
Protonex chief executive Scott Pearson said: "This achievement comes as a direct result of our focused effort, working with AeroVironment and the AFRL to advance UAV endurance and payload capacity."
On 1 November, Singapore based-Horizon Fuel Cell Technologies announced the 128km (69nm) flight of the propeller-powered Pterosoar, a joint effort between California State University of Los Angeles and Oklahoma State University.
During that flight, the Pterosoar flew for 2h 58min using Horizon Fuel Cell Technologies' product capable of 480W/kg power density. The company was expecting to make a 15.5h flight weeks later but that is now delayed to June 2008.