GLENN W. GOODMAN, JR. Unmanned Combat Air Vehicles http://www.armedforcesjournal.com/ISR/Mags/2002/Issue3/unmanned.html US Air Force, Navy Developing Re-useable, Autonomous, Jet-Powered Drones The first flight of a US unmanned (or uninhabited) combat air vehicle (UCAV) on 22 May 2002 was a major milestone for those potentially transformational new pilot-less aircraft. As a military program official had remarked previously, "The objective of our first flight is our first landing!" UCAV development is now clearly picking up momentum. Boeing's X-45A technology demonstration aircraft flew for 14 minutes that day and was set to fly again late last month, kicking off a multi-year flight test effort. Basic flight performance, along with the command and control link between the aircraft and its mission-control station, were successfully demonstrated during the first short flight. The X-45A is an initial demonstrator for an operational UCAV system being developed jointly by the Defense Advanced Research Projects Agency (DARPA) and the Air Force, particularly the Air Force Research Lab. The objective of the DARPA/Air Force program is to demonstrate "the technical feasibility, military utility, and operational value" of an affordable, re-useable, stealthy UCAV that could conduct suppression of enemy air defenses (SEAD) and strike (destruction of high-value target) missions using air-to-surface weapons. The Air Force accelerated its UCAV program earlier this year, with a goal of fielding its first operational squadron around 2008. There is a separate DARPA/Navy Advanced Technology Demonstration program, a step or two behind the DARPA/Air Force effort, for a Naval UCAV (UCAV-N). The Office of Naval Research also is a key player. Unlike Air Force UCAVs, which will be stored as "silver bullets" and used selectively in air campaigns, the DARPA/Navy effort aims to develop a slightly larger stealthy UCAV with longer range that would be based routinely on an aircraft carrier. As a Navy program official said, "We can't afford to bring an airplane on board a carrier...and not have it operating on a regular basis." The UCAV-N's primary mission would be reconnaissance over heavily defended areas. It would take off and land like a manned carrier aircraft using catapults and arresting gear. As a result, carrier operations, including safe deck handling as well as launch and recovery, present the greatest challenges in the UCAV-N development effort. The unmanned aircraft's requirements call for it to fly persistent surveillance missions of more than 12 hours. SEAD and deep strike would be secondary missions for the UCAV-N. In fact, the UCAV-N fits into the Navy's long-term strategy, released early this year, for a family of unmanned aerial vehicles (UAVs) to be used for surveillance missions, including a Global Hawk-like UAV for broad-area maritime surveillance. UCAV-N would fill the role of a stealthy surveillance aircraft that could penetrate heavy enemy air defenses. The UCAV-N program progressed into its next phase of development on 8 May 2002, when DARPA awarded $10 million Phase II contract modifications to Boeing and Northrop Grumman to continue working on their respective X-46 and X-47 UCAV-N designs and operational concepts. The two companies previously conduced Phase I preliminary design and trade-off study contracts in 2000-2001. Phase II is divided into Phase IIA advanced technology development and risk-reduction activities through 30 September 2004 and Phase IIB flight demonstrations extending to mid-2005. The Navy may only fund one company for the flight demonstrations. Boeing's X-46 design, with a bat-wing shape, resembles a small B-2 (Northrop Grumman) stealth bomber. Northrop Grumman says its X-47 will be a scaled-up version of its diamond-planform X-47A Pegasus technology demonstrator. Northrop Grumman's Integrated Systems sector has funded Pegasus with company funds to demonstrate aerodynamic qualities, such as low speed handling, suitable for autonomous operation from an aircraft carrier. The tail-less, kite-shaped X-47A measures about 28 feet long and has a 28-foot wingspan. Pegasus is powered by an off-the-shelf Pratt & Whitney JT15D turbine engine. (Northrop Grumman's X-47B operational design will be scaled up from the X-47A and will be powered by a turbofan engine to allow it to carry a sizeable payload.) The first flight of Pegasus is expected later this year at the Naval Weapons Center, China Lake, CA. AIR FORCE PROGRAM Boeing has built a second X-45A demonstration aircraft, which will start flying later this year. The X-45A is 26.5 feet long with a 33.8-foot wingspan. Boeing is designing a larger demonstrator aircraft, the X-45B, that will join the flight test program in 2005. Its dimensions are reportedly 36 feet long with a 47-foot wingspan. Three of the aircraft are to be built. The X-45B will more closely represent the operational system as now envisioned (rather than requirements set in 1998), with two internal weapons bays, integrated avionics, and low-observability features. It will be powered by GE Aircraft Engines' F404-102D, a variant of the engine used on the Navy's F/A-18 fighters. The X-45A's powerplant is the Honeywell F124 engine. The two X-45s will fly together next year to begin demonstrating coordinated flying, communication between multiple UCAVs, and cooperative targeting. Such multi-aircraft flight tests, according to a DARPA statement, "are the technical heart of the program and the key to unlocking the transformational potential of this revolutionary weapon system." The Air Force plans a major exercise in late 2005 involving several X-45Bs, manned aircraft, and UAVs operating together as a joint strike force. The Air Force UCAV would carry two target acquisition sensors: an electronic support measures (ESM) system, which can passively detect enemy (air defense) radar emissions and determine the radar's approximate location by obtaining several line-of-bearing measurements to it; and a synthetic aperture radar (SAR), which would be used to take a high-resolution, still frame photo-like image of the target area through clouds and adverse weather. A flight of three or four UCAVs would hunt targets as a pack and would be controlled by a single operator in a ground station. The UCAVs would jointly triangulate the locations of enemy air defense radars using their ESM systems and secure line-of-sight links to communicate with each other. The UCAVs would send SAR images back to a mission control station to verify a target before a commander gave approval for the UCAVs to attack it. The aircraft, which will have a mission radius of 500 to 1,000 nautical miles, is being designed to carry a weapons payload of 1,000 to 3,000 pounds: two 500-pound or 1,000-pound GPS-guided Joint Direct Attack Munitions or twelve 250-pound Small Diameter Bombs (now in development). A lighter payload or shorter-range mission would allow more loiter time over hostile territory. UCAVs won't do formation flying with manned fighter aircraft; for collision-avoidance safety reasons, the UCAVs will fly many miles away from the fighters-and far from each other-as the lead element of a strike package, suppressing air defenses ahead of the manned fighters. The X-45B will be a "fieldable" prototype; the Air Force and DoD approved additional funding late last year to complete the X-45B's development and to deliver 14 UCAVs by 2008. NAVY PROGRAM The UCAV-N's requirements call for a 2,000 mile surveillance radius and a 1,000 mile strike radius, which a program official noted, "could very easily cover all the targets in Afghanistan" without refueling from an aircraft carrier in the Arabian Sea. The UCAV-N will carry a number of surveillance sensors: electro-optical/infrared, ESM, and a radar with both SAR and Ground Moving Target Indicator modes. Like USAF's X-45B, the UCAV-N will have two weapons bays, but they will carry up to 4,000 pounds of bombs on strike missions. The cost goals for the UCAV-N are an acquisition cost of one-third that of the Naval Joint Strike Fighter, currently in development, and a 50 percent reduction in operating and support costs compared to the F/A-18C. The Navy hopes to transition the UCAV-N effort into a formal acquisition program in 2004. ARMY'S UCAR Not to be left out, the Army also plans to work with DARPA to exploit UCAV-like technologies, except that it wants to develop a vertical take-off and landing aircraft-an unmanned helicopter-to enhance Army Aviation's reconnaissance and attack capabilities. On 28 May 2002, DARPA and the Army awarded four industry firms or teams $3 million, one-year contracts for the first phase of the Unmanned Combat Armed Rotorcraft (UCAR) program: Boeing; Lockheed Martin Systems Integration-Owego (NY) and Bell Helicopter Textron; Northrop Grumman's Integrated Systems sector; and Sikorsky Aircraft teamed with Raytheon Electronic Systems. During Phase I, according to a DARPA statement, "each team will conduct mission effectiveness and affordability trades to develop and optimize an objective system design." The UCAR system, rather than employing a dedicated mission control station, will be controlled by personnel in the air aboard manned helicopters, such as the Comanche or the UH-60 Black Hawk-based Army Airborne Command and Control System, or by ground-based command centers. The DARPA statement noted, "The UCAR system will be capable of increased autonomy during mission execution, relying on a human controller primarily for tasking and final weapons release authorization. UCAR will be capable of autonomous collaboration with unmanned and manned air and ground systems, and will operate at low altitude in close proximity to manned and unmanned systems." As its name implies, UCAR will carry weapons that will enable it to strike ground targets itself. Following the completion of Phase I, DARPA and the Army will decide whether to proceed with two firms or teams into a nine-month Phase II. During Phase II, the contractors will each complete the preliminary design of their demonstration system, which will be tested in a subsequent system development phase. A final system concept will be developed and tested during a system maturation phase. DARPA plans to transfer the program to the Army in 2009. The Army tentatively plans to field UCAR by 2015 and projects its cost at about one-third that of a Comanche helicopter-roughly $8 million. DARPA's ongoing efforts to develop unmanned combat aircraft for the Air Force, Navy, and Army should begin to answer a lot of questions about the operational utility, affordability, and drawbacks of these pilot-less systems after many years of optimistic speculation within the services.