New Horizons for Combat UAVs

Dec. 1, 2003

The Air Force is rapidly increasing the effort and funding it devotes to the development of unmanned aerial combat systems, in the hope that, in about a decade, unmanned aircraft will be ready to take on some highly dangerous missions now performed by manned aircraft.

The success of unmanned aerial vehicles in recent conflicts has highlighted the potential of such systems. Predator UAVs, originally designed as reconnaissance drones, were armed with Hellfire missiles and successfully used to attack targets in Afghanistan, Yemen, and Iraq. Service officials say that initial cultural problems (pilots were reluctant to fly “drones” for fear of harming their careers) are being overcome.

UAV advocates contend the successful attacks on al Qaeda, Taliban, and Iraqi targets using weaponized Predators, now designated MQ-1s, provide just a glimpse of what unmanned systems can accomplish in the future.

According to its Unmanned Aerial Vehicles Roadmap, DOD projects it will invest $10 billion over the current decade for UAVs, compared to about $3 billion it spent during the 1990s. That investment largely will be overseen by a new joint systems management office the Pentagon created on Oct. 1 to guide development of the next generation of weaponized UAVs, known as unmanned combat aerial vehicles.

Currently, there are two key programs: USAF’s X-45 and the Navy’s carrier-capable X-47. Both projects will continue but under the aegis of the Joint Unmanned Combat Air System (J-UCAS) program. The Defense Advanced Research Projects Agency, which had been working with both services on their individual systems, will lead the joint effort.

Pentagon leaders believe that merging the two projects will lead to greater efficiencies and, potentially, reduced acquisition costs, but DOD has no plan to shift from two systems to a single UCAV.

There is “much less emphasis” than in the past on moving to a common platform, Dyke Weatherington, deputy director of the UAV planning task force for the Office of the Secretary of Defense, told Air Force Magazine. He added that the Air Force and Navy will continue to determine their own requirements.

The services have pursued different goals in their respective programs. The Navy, of course, requires a vehicle suitable for use aboard a carrier and has placed more emphasis on surveillance than on strike. In contrast, the Air Force is interested in suppression of enemy air defenses and electronic attack capabilities.

Weatherington said that vehicle evaluation will continue until about 2007, at which time both systems will undergo a rigorous two-year operational assessment. Once that is complete, he said, decisions will be made on how to proceed to acquisition.

Questions Persist

Despite their promise, unmanned aircraft still have many problems, not the least of which is that the services still have poorly defined requirements.

Gen. John P. Jumper, Air Force Chief of Staff, has questioned blind devotion to unmanned systems per se. He said that, after the success of the armed Predator in Afghanistan, “everybody wanted to jump to the extreme conclusion.”

The popular position was to “take everybody out of cockpits,” said Jumper. “Let’s make them all go unmanned.”

However, he cited the challenges the Air Force faces in making UAVs effective strike systems. “We have a debate going on about the UCAV today,” Jumper said. “I asked a group one day, ‘If it weren’t for the novelty of not having a man in it, would we even be thinking about this vehicle?’ The room was silent because the answer is no,” the Chief said.

Jumper went on to say that he is not ruling out a vehicle “that absolutely advances the mission an order of magnitude [and] that happens not to have a person in it.”

Gen. Hal M. Hornburg, commander of Air Combat Command, put it this way: “I want them to do more than just be unmanned.”

The Air Force needs UAVs that can fly in tight formations, as do manned fighter aircraft. Without that capability, said Hornburg, the service cannot achieve the necessary “strike package density.” Additionally, despite their long loiter times—typically more than 24 hours— UAVs should be able to refuel in the air. “That’s a technical challenge,” noted Hornburg.

Without such improvements, said the ACC boss, UAVs have little to offer as strike platforms, so “take the argument somewhere else.”

Future systems should combine new capabilities with what is already desirable about UAVs, Jumper said. The future UAV “has to persist for long periods of time over the battlefield and be able to survive,” he said. “It has to be able to defend itself … [and] be able to air refuel in order to get that persistence.”

And, once it has an aerial refueling capability, Jumper emphasized, “it had better carry enough weapons to be useful to the people on the ground,” because the UAV is “no longer a razor blade that we consider dispensable. It is now a Norelco, and it costs a lot of money.”

That was Hornburg’s point, as well. “I remember the days when Predators crashed and no one really cared,” he said. “Now we care a lot. … These things are valuable.”

The unit cost for an MQ-1 Predator A air vehicle is roughly $4.5 million. When the Air Force starts building newer systems, such as the larger MQ-9 Predator B, with more expensive sensors, said Hornburg, “You’ll find the price of the sensors exceed the price of the airplane.” He added, “They’re not going to be expendable.” The more advanced UCAVs will see similar cost increases as new command, control, and weapons requirements drive up unit costs.

There is a balancing act. UCAVs must make unique contributions to the fight but do so without being overburdened by a requirements creep that threatens to make the systems too valuable to risk on high-threat missions. Hornburg said that Air Force leaders must think about what the UCAV mission is going to be before they start “spending the treasury” on them and conclude they should have “gotten more” for the money.

Weatherington agreed that UAVs should not simply replicate capabilities already present in manned fighters. “An unmanned system, without bringing any unique characteristics to the fight, is probably a novelty,” he said. “But those [unique] characteristics can be things like endurance, signature, lower operational cost.”

By taking “the man out of the system, you afford yourself design trade space” not otherwise present, he said.

For example, the Global Hawk intelligence-surveillance-reconnaissance UAV achieves much greater endurance than is possible with a pilot aboard. “Does Global Hawk inherently have much better capabilities than a U-2 does?” Weatherington asked. “Outside of endurance, most people would say no,” he said, and added, “In fact … from a platform perspective, some people would make the argument that a Global Hawk is less capable than a U-2. It’s got less payload, less power on the platform.”

What Global Hawk does provide, though, is a level of endurance that the warfighter “has said is critical to the prosecution of the mission,” added Weatherington.

An unmanned system provides “design flexibility that I don’t have in a manned system,” he explained.

As an example, he cited signature control. The cockpit of a manned fighter is a significant contributor to the radar cross section of a fighter. Using an unmanned system for a specific mission, such as SEAD, would offer the potential for much greater signature control. UAVs could fulfill this type of “crying need” for more capability, said Weatherington.

Keeping Cost Down

UAVs should ultimately help with the bottom line in the cost of flying operations and maintenance, although, as Weatherington pointed out, when the current batch of UAVs were being developed, “some people would say [cost and performance] weren’t defined at all.” The Pentagon needs to make up for lost time. Once requirements are better defined, cost should actually work to the advantage of unmanned systems.

About 90 percent of a manned combat aircraft’s flying life is devoted to flights other than combat—primarily training missions. With UCAVs, that “ratio should change pretty significantly,” said Weatherington.

Initially, UCAVs will fly a lot of training missions “because people generally will have some hesitancy that [UCAVs] can perform the mission,” he said. “Once we overcome that inertia,” the UCAVs will not have to be flown every day to prove they work. This means the total number of hours a tactical combat air system spends in the air “could be significantly reduced,” compared to comparable manned systems, he said.

That would translate into real cost savings through lower maintenance, fuel, and parts requirements. The majority of an aircraft’s life-cycle cost comes from long-term operating and maintenance expenses.

However, some analysts argue that UAVs have a reliability problem. An April 2003 Congressional Research Service report noted, “The current UAV accident rate … is 100 times that of manned aircraft.”

The Air Force stated that the 2002 accident rate for Predators was 32.8, which means that 32.8 Predators were damaged or destroyed per 100,000 flying hours. However, Weatherington pointed out that not a single UAV has actually amassed 100,000 flight hours. The accident rate was extrapolated from early developmental data.

In fact, Weatherington maintained that UAV reliability is not all that different from the levels shown by manned aircraft at comparable points in their development. He believes reliability will improve as the systems mature.

The Pentagon is counting on that. The UAV roadmap predicts that in 2012, “DOD will probably be operating F-16-size UAVs capable of supporting a variety of combat and combat support missions, including [SEAD], electronic attack, … and possibly deep strike interdiction.”

The X-45 UCAV

The Air Force’s new unmanned combat aerial vehicle—the Boeing X-45—is expected to take over suppression of enemy air defenses and electronic attack missions.

Gen. Hal M. Hornburg, commander of Air Combat Command, said that ACC sees great future benefit in a squadron of UCAVs that can “go in and kill an entire [integrated air defense system] network.”

Two X-45A prototypes, which were first flown successfully in 2002, bear little resemblance to the operational system USAF now expects to field around 2010.

The service scrapped plans for an X-45B, opting instead to go directly to work on an X-45C variant. The initial X-45C air vehicle will more closely approximate the objective UCAV system. It will have a new, larger airframe with dual internal weapons bays and demonstrate stealth characteristics. The X-45C will be able to deliver two 2,000-pound Joint Direct Attack Munitions. First flight for X-45C prototype is expected in 2005.

At about 35,000 pounds, the C model will weigh nearly three times as much as the X-45A. Its length will increase by 10 feet to 36 feet, and its wingspan will grow nearly 50 percent to 48 feet.

As a stealthy, flying wing design, the X-45C will look somewhat like a B-2 stealth bomber.

Predator’s Larger Brother

The MQ-1 Predator A has become a known and trusted commodity to the warfighter through its successful use in Operations Enduring Freedom and Iraqi Freedom.

Continuous upgrades and innovation have made the Predator A “something you wouldn’t think of going to war without,” Gen. Hal M. Hornburg, commander of Air Combat Command, told Air Force Magazine in September.

The Air Force determined it needed a multirole UAV “that would go faster, longer, [and] would process more,” Hornburg noted. The service also wanted the UAV to have a greater weapons capability.

The service began working with General Atomics Aeronautical Systems to develop a larger Predator, dubbed the MQ-9 Predator B, which first flew in February 2001.

The MQ-9, powered by a more powerful turboprop engine, has demonstrated in contractor tests the ability to carry up to eight Hellfire missiles, two Joint Direct Attack Munitions, and two air-to-air missiles, among other configurations. (USAF has not set the exact Predator B loadout requirement.) The MQ-1, for comparison, is limited to a pair of Hellfires.

The B model is also significantly larger—at five tons, it is more than four times heavier than an A model. Its 64-foot wingspan is more than twice that of the Predator A.

The Predator B shows great potential, “but right now it’s not proven,” Hornburg said.

According to DOD’s Unmanned Aerial Vehicles Roadmap, the Predator A and B variants will likely work together in future battle zones. “The MQ-9 could serve as the killer portion of an MQ-1–MQ-9 hunter-killer UAV team,” the roadmap reads.