Navy’s Unmanned Combat Aircraft Flying Under Cloud of Uncertainty

By Sandra I. Erwin
The Navy expects to invest a growing share of its aviation research dollars in unmanned aircraft as it seeks to extend the reach and endurance of its carrier-based air wings.

The science behind unpiloted flying is well understood by now, after years of progressively more frequent deployments of drones by the U.S. military. Scientists have perfected technologies such as autonomous flying — which does not require a controller on the ground — and in-flight refueling of unmanned aircraft. They are now finding that the technology, although mature, is running up against policies that could hinder its progress. Rules that restrict independent UAV flying, experts contend, are expected to slow the expansion of unmanned aircraft.

“Making an unmanned vehicle fly is not a challenge. It’s an airplane, and we understand those pretty darn well, whether they’re large or small,” said Rebecca Ahne, deputy chief technology officer of the Naval Aviation Enterprise, under the Naval Air Systems Command, in Patuxent River, Md.

The NAE oversees the Navy’s and Marine Corps’ $40 billion worth of aviation programs, including 3,700 aircraft and 11 aircraft carriers.

Ahne said the naval aviation community, like its Air Force and Army counterparts, is comfortable operating remotely controlled aircraft, but it could be awhile before more advanced autonomous systems are seen taking off and landing on carrier decks.

“Technology issues are easy if we are just talking about flight,” Ahne said in an interview. “If it’s a truly autonomous aircraft, are we comfortable with that, that it can avoid collisions” with other aircraft or with terrain? she asked. Ahne does not see any technological barriers to having combat aircraft flying autonomously, but she sees “lots of policy issues” that have to be resolved before engineers can continue to push the technology. “Whether we’ll be allowed to do that [fly autonomously] certainly drives technology,” she said. “Instead of truly autonomous, do we need a system that can alternate between autonomous and man in the loop?”

There are also well-known regulatory barriers that are imposed by the Federal Aviation Administration that limit unmanned aircraft flying in U.S. airspace. Safety concerns are magnified when it comes to the crowded deck of an aircraft carrier, where UAVs would have to share the congested airspace and deck area with manned aircraft and crews.

“The biggest challenges are control and communications,” Ahne said. There is no clear consensus on what level of autonomy vehicles should have, she added. For the Navy, the questions are whether the UAV will take off and land on its own, whether it decides on its own if it has to turn right or left, or if the vehicle in flight will independently make decisions about data collection and dissemination of information, or even about launching and controlling a weapon. “The policy implications have to be addressed before the technical pieces fall into place,” Ahne said. “Trying to get all that to line up at the same time is very challenging.”

As the Navy’s family of unmanned systems expands, policy and operational questions increasingly will beg for answers, she said. The Navy now operates small, large, rotary-wing and fixed-wing UAVs, with some weaponized, and some used only for surveillance. “The questions are creeping more and more, and getting more complex.”

These concerns create a cloud of uncertainty over the future of unmanned aviation, and come at a time when the Navy is looking to shift more of its research dollars into autonomous robotic technologies. Other larger, and politically sensitive, questions about how far to push the autonomy of weapon systems also are being raised as the U.S. military and the CIA continue to be criticized for drone strikes that have killed civilians.

The Office of Naval Research recently unveiled a new “Naval S&T Strategic Plan” that calls for greater use of unmanned systems. ONR expects to allocate a portion of its $1.3 billion budget to technologies that meet a “requirement to augment expensive manned systems with less expensive, unmanned fully autonomous systems that can operate in all required domains.” The goal is a “hybrid force of manned and unmanned systems with the ability to sense, comprehend, predict, communicate, plan, make decisions and take appropriate actions to achieve its goals,” said the ONR plan. “The employment of these systems will reduce risk for sailors and Marines and increase capability.”

Separately from ONR’s investments, the Naval Aviation Enterprise spends about $350 million to $400 million a year on science and technology.

“The unmanned portion of investment has grown over the past few years,” Ahne said. But advances are going to be difficult to achieve unless “policy and technology issues are worked concurrently,” added Ahne.

Carrier-based unmanned aviation reached a significant milestone in February when the X-47B combat aircraft flew from Edwards Air Force Base, Calif. The first aircraft carrier landing is scheduled for 2013, and there are plans to test autonomous aerial refueling as well.

The X-47B, built by Northrop Grumman Corp., is a $2 billion project to test the limits of unmanned aviation in the naval environment. The aircraft is considered a linchpin in the Pentagon’s efforts to deploy long-range strike weapons against technologically advanced future enemies.

Navy leaders are hopeful that, if the project is successful and if they can secure funds, they can launch a major procurement of a so-called UCLASS, or unmanned carrier-launched airborne surveillance and strike aircraft. Besides the X-47B, other expected contenders are the General Atomics Aeronautical Systems’ Avenger and a modified version of Boeing’s Phantom Ray aircraft.

Carl Johnson, program manager for unmanned combat air systems at Northrop Grumman, said the technology is advancing rapidly, but there are still unresolved procedural issues. “There aren’t that many technical constraints,” he told National Defense. “The question is more about policy, procedures, how do you handle automation, what is the protocol, is there a man in the loop?”

The culture has yet to catch up with the technology, Johnson said. “We’re not ready yet for that kind of mentality in unmanned systems.”

At their most basic level, UAVs are flown by a human “in the loop” with a joystick, then they progress to “man on the loop,” which allows the operator to override the machine. “Then you look at how you might allow advanced levels of autonomy and how policies will enable that,” said Johnson.

The X-47B is being designed to fly in highly defended airspace, and even when GPS satellite navigation signals are blocked. “The technologies for survivability are very mature,” said Johnson. In the absence of communication links, “there are approaches that an autonomous UAV can deal with,” he said. The prototype that is now being tested is “probably the most advanced autonomous UAV that has been demonstrated,” said Johnson.

Its electronic brain consists of “decision aids” that can self-route the aircraft, and allow it to hook up with an aerial refueling tanker. A pivotal test will be whether it can land itself on a moving aircraft carrier.

“Senior Navy leadership has indicated there will be an unmanned presence on carriers,” said Johnson. “They’re pretty clear that they’re going to continue down that path.”

It is still unknown how the upcoming Pentagon budget crunch will affect unmanned combat aviation programs. Dyke Weatherington, the Defense Department’s deputy director for unmanned warfare, told an industry conference in December that he expects a slowdown in procurement of new unmanned aircraft. “I do think the preponderance of what we see in the near future is improvements to current capabilities rather than a whole lot of new programs,” he said.

Ahne said naval researchers are mindful of the budget constraints and are seeking to balance near-term priorities against futuristic projects. “It’s an art, not a science,” she said. “We’re getting better at it.”

Immediate research efforts today focus on lowering the costs of supporting and maintaining existing weapons, also known as “total ownership costs.” That includes better sensors for prognostics so aircraft crews can identify problems in the field, wireless sensors that can operate on ships and communicate with components, and systems that manage the data from the sensors and interpret the results. “These investments are spread across rotary-wing, fixed-wing and unmanned aviation,” Ahne said.

Her office also is exploring the use of new materials for use in aircraft engines that last longer and won’t corrode in the maritime environment.

On the long-term wish list are improved helicopters, with greater cargo capacity, farther range and better survivability, Ahne said. “It is not technically possible to extend the range beyond where we are today.” On the fixed-wing side, “everyone talks about sixth-generation fighter,” Ahne said. “I have never seen what a sixth-generation fighter is, put on paper. But we have some general ideas about what that aircraft has to do.”                                 

Topics: Robotics, Unmanned Air Vehicles

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