December 11,2008: The U.S. Air Force has successfully tested autonomous landing software on an F-16 fighter. Such systems have been available for commercial aircraft since the 1990s. Last year, the U.S. Air Force successfully tested such systems on C-130 transports. Earlier this year, the replacement for the MQ-1B Predator UAV, the MQ-1C Sky Warrior, successfully tested automatic landing and takeoff software. This makes the aircraft easier and safer to use, and also is one step closer to a fully autonomous aircraft. There are already some fully autonomous UAVs, that can operate without any human control. The air force is particularly keen on making their UAVs more autonomous, to help ease the stress on its overworked UAV crews. Such automated systems on manned aircraft reduces the workload for the pilot.