Production of Shadow aircraft shifted to a generally improved RQ-7B variant in the summer of 2004. The RQ-7B features new wings increased in length to . The new wings are not only more aerodynamically efficient, they are "wet" to increase fuel storage up to 44 liters for an endurance of up to 6 hours. The payload capability has been increased to . After reports from Iraq that engines were failing, in 2005, the Army's UAV project manager called for the use of 100LL, an aviation fuel, rather than the conventional 87 octane mogas. Avionics systems have been generally improved, and the new wing is designed to accommodate a communications relay package, which allows the aircraft to act as a relay station. This allows commanders or even the aircraft operators themselves to communicate via radio to the troops on ground in locations that would otherwise be "dead" to radio traffic.