January 17, 2012:
The U.S. Navy has done the math and realized that they need unmanned combat aircraft (UCAS, or Unmanned Combat Air System) on their carriers as soon as possible. The current plan is to get these aircraft into service six years from now. But there is an effort to get the unmanned carrier aircraft into service sooner than that. The math problem that triggered all this is the realization that American carriers had to get within 800 kilometers of their target before launching bomber aircraft. Potential enemies increasingly have aircraft and missiles with range greater than 800 kilometers. The navy already has a solution in development; the X-47B UCAS has a range of 2,500 kilometers
Last year the U.S. Navy leadership also ordered naval aviation commanders to examine the possibility of reducing orders for the new F-35B and F-35C manned aircraft, and use that money to buy the new X-47B, and similar robotic combat aircraft. The navy currently plans to buy 680 F-35B and F-35C aircraft for (on average) $100 million each. A UCAS (Unmanned Combat Aerial System) costs less than half that, and provides most of the same capabilities, plus much longer range.
For most of the last decade, the navy has been hustling to ready a UCAS for carrier operations and combat use. Within four years, the navy expects to have the X-47B demonstrating the ability to regularly operate from a carrier and perform combat (including reconnaissance and surveillance) operations. The new efforts aim to have UCAS aircraft perform ground attack missions as well, something the Predators have been doing for over a decade. The larger Reaper UAV was designed to expand this combat capability, and is being built as quickly as possible to replace F-16s and other bombers in the combat zone.
The 20 ton X-47B weighs a little less than the 24 ton F-18A, and has two internal bays holding two tons of smart bombs. Once it can operate off a carrier, the X-47B will be used for a lot of bombing. Sort of a super-Reaper. The navy has been impressed with the success of the Predator and Reaper. But the Reaper weighs only 4.7 tons. The much larger X-47B uses a F100-PW-220 engine, which is currently used in the F-16 and F-15.
It was only two years ago that the U.S. Navy rolled out the X-47B, its first combat UAV (now known as a UCAS). This was part of a six year long, $636 million contract to build and test two X-47B aircraft. With internal fuel it can go 2,700 kilometers and return to its carrier. This greatly expands the reconnaissance capability of a carrier.
Seven years ago, the smaller X-47A UCAS made its first flight. Development of this aircraft began in 2001. The Air Force was also developing the X-45 UCAS, which also had a naval version (the X-46). The X-45 program began in 1999, and the eight ton (max takeoff weight, with two ton payload) aircraft was ready for operational tests in 2006. The X-46 has a different wing layout and a range of 1,100 kilometers, carrying a payload of two tons. The X-47A also has a two ton payload and a range of 1,600 kilometers. Unlike the X-45, which is built to be stored for long periods, the X-47A was built for sustained use aboard a carrier. All of these aircraft are very stealthy and can operate completely on their own (including landing and takeoff, under software control). The UCASs were originally meant for dangerous missions, like destroying enemy air defenses, and reconnaissance where enemy air defenses were strong. The air force, however, cancelled its X-45 but is now considering other UCAS options.
The air force and navy have always differed about the widespread use of UAVs in combat. When the air force agreed to work with the navy on UCASs a decade ago the idea was that the air force ones would largely remain in storage, to provide a rapid "surge" capability in wartime. The navy, however, wanted to use theirs to replace manned aircraft on carriers. The reason was simple; carrier ops are dangerous, and carrier qualified pilots are more difficult and expensive to train, and retain in the service. The navy still has these problems and senior admirals are pretty much in agreement that UCASs are the future of carrier aviation. The sooner these UCASs prove they can safely and effectively operate from carriers, the better. The X-47B (or planned, slightly larger, X-47C) is not the definitive carrier UCAS, but the navy hopes it is good enough to show that unmanned aircraft can do the job. Normally, "X" class aircraft are just used as technology demonstrators. But the X-47 program has been going on for so long, and has incorporated so much from UAVs already serving in combat, that the X-47B may end up eventually running recon and bombing missions as the MQ-47B.
The DARPA project is, in effect, the Department of Defense leadership backing the navy plans, and spurring the air force to catch up. At the moment, the air force has a hard time building enough MQ-9s, which are used as a ground support aircraft, in addition to reconnaissance and surveillance. But, as the navy is demonstrating, you can build UCAS that can carry more weapons, stay in the air longer, and hustle to where they are needed faster. DARPA will try to demonstrate this, but it will be up to the air force and navy (and maybe even the army), to make it happen.