Earlier this year, a critical component of the Joint Unmanned Combat Air System (J-UCAS) was demonstrated off the east coast of the US. In February, the shipboard mission control system (that allows UCAVs to operate from carriers) was tested aboard the aircraft carrier USS Harry S. Truman. The test involved the operator of the UCAV, simulating changing the mission plan of the vehicle in flight in response to new air traffic control requirements, system failures, or changes in enemy activity.
The J-UCAS program is an effort by the Defense Advanced Research Projects Agency (DARPA), the US Air Force, and the US Navy to develop a new fleet of unmanned
combat aerial vehicles (UCAVs). For this test a manned King Air airplane was used as a surrogate for the X-47B UCAV. The King Air, operating from a shore base, flew five sorties to the Truman. Each sortie consisted of approaching the carrier, entering its air traffic control pattern, "waving off," and then circling back around.
During each approach, the surrogate's software received instructions from the carrier-based Joint Precision Approach and Landing System air traffic control system, to adjust the aircraft's pattern and descent down to a trap (landing) aboard the ship. Simultaneously, the mission management system relayed the instructions to a small computer attached to the co-pilot's steering yoke, and to the J-UCAS shipboard mission control system. While in normal operations, the J-UCAS air vehicle would respond directly to carrier air traffic control center instructions via its mission management software, just like a manned aircraft, for this demonstration the surrogate aircraft pilots executed the instructions manually to validate the integrity of the data link.
The J-UCAS program was established to create a combat UAV for both the Navy and Air Force that also can perform suppression of enemy air defenses; electronic warfare; bombing and reconnaissance. The J-UCAS aircraft must, as a minimum, have an operational radius of 2,170 kilometers, a two hour loiter capability at 1,660 kilometers range, and carry at least 4,500 pounds of weapons and equipment. It must also use a Common Operating System to let it operate with and be operated by appropriate allied forces and task groups.
The Navy and Air Force continue to assert that UCAVs are not intended to replace any manned tactical aviation, but rather, will augment manned aircraft. However, with a public and political culture becoming increasingly and unrealistically reluctant to accept any US combat deaths, this assurance seems premature (in fact, the USAF has already started advertising for people to join-up as warrant officer UCAV pilots and NCO mission specialists).
Earlier, an X-45A technology demonstrator for the Joint Unmanned Combat Air Systems (J-UCAS) program made history by releasing an inert Global Positioning System-guided Small Smart Bomb and hitting a ground target at the Naval Air Warfare Center Weapons Division Range, China Lake, CA., marking the first time that an unmanned aircraft had released a GPS-guided weapon. Once the operator authorized release and the aircraft determined it was within range, it dropped the GPS-guided 250-pound weapon from its internal weapons bay at 35,000 ft. while flying at a speed of 730 kph. The aircraft autonomously performed all attack maneuvers, bay door operations, and weapon-away release sequences under human operator supervision. The bomb hit within a few feet of the target.
In 2003, the X-47A demonstrated low-speed handling qualities, air vehicle performance and navigation performance collection. It also simulated a tailhook arrestment point on a carrier flight deck by landing near a pre-designated touchdown point and utilized the shipboard-relative global positioning satellite (SRGPS) system as the primary navigation source for increased landing precision. In May of 2003 DARPA awarded a $160 million contract to build and demonstrate at least two X-47B UCAVs with a target date of 2006.
The next test in the J-UCAS series will be wind tunnel testing of the X-47B airframe configuration in the fall of this year. Aircraft operating from an aircraft carrier must be able to maneuver well in both low-speed launch and recovery operations on a short flight deck as well as in high-speed transit to station and evasion regimes. This requirement has meant that many aircraft used by the Air Force have foundered when an attempt was made to adapt them to carrier aviation (the ill-fated F-111 comes to mind). Operational Assessment flights of the air vehicles are scheduled for the 2007-2009 timeframe, with J-UCAS going operational after 2010. K.B. Sherman