Monrovia-based Aerovironment, the developer of unmanned aircraft systems, said today that it has received a nearly $6.9M order from the U.S. Air Force. AeroVironment said the order goes for its Raven small unmanned aircraft systems and spares. The company explained the order came under and existing contract with the U.S. Army. AeroVironment's unmanned aircraft are used for reconnaissance, surveillance, and target acquisition by the military.