Robotic warplanes, finding and attacking targets by themselves, have been successfully tested. On August 10th, two American X-45A UCAVs (Unmanned Combat Aerial Vehicles) were sent out into a test range that had a hostile anti-aircraft system on it. The X-45As successfully detected the potential attack, avoided took evasive action, then planned and carried out their own attack, destroying the enemy anti-aircraft system. While a human pilot on the ground monitored all of this, and could have interrupted the operation at any time, the X-45As were allowed to operate on their own. This included talking off, returning and landing.
Flight control software has been a mature technology for over a decade. It just keeps getting better (more reliable, flexible and cheaper). Adding combat oriented AI (artificial intelligence) is obviously not a problem, although combat AI is a less mature area. But the main purpose of the X-45A is to test and perfect the flight control and combat AI systems for the larger, X-45C UCAV, which will enter service with the U.S. Navy and Air Force in five years or so. The UCAVs are intended to deal with particularly dangerous missions, like taking out enemy air defenses. But UCAVs can also be equipped with AI to handle fighting hostile aircraft. The air force and navy are less enthusiastic about that, even though a UCAV would have several advantages over a piloted aircraft. UCAVs are smaller and more maneuverable than a manned aircraft of the same general capabilities. This makes UCAVs a harder target to spot and hit. Human pilots are limited in some of the high speed maneuvers they can physically handle. This is not a problem with UCAVs, which makes them harder to avoid, and more difficult to knock down. The flying robots also think faster as well. However, it all depends on the software. Pilots are not happy about the possibility of being replaced by a bunch of geeks, but that's where things are headed.
The X-45A is 27 feet long, has a wingspan of 34 feet and has a payload of 1.2 tons. The X-45C, weighs 19 tons, has a 2.2 ton payload and is 39 feet long (with a 49 foot wingspan.) Officially, its called JUCAS (Joint Unmanned Combat Air System), because the navy and air force will both use it. The X-45C has a combat radius of 2,300 kilometers, or can go out 1,800 kilometers, hang around for two hours, and return. The X-45C can stay in the air for about six hours on internal fuel. The X-45C is being built to handle in-flight refueling. Since it doesnt carry a pilot, aerial refueling can be done several times if theres a need to keep the aircraft up there, and there are no equipment problems.