EXCLUSIVE: X-47B May Begin Automated Aerial Refueling Demonstrations Next Year

The Navy’s carrier-based unmanned aircraft demonstrator is undergoing preparations for automated aerial refueling testing next year, including a possible flight demonstration using the aircraft itself, said officials from the service and X-47B manufacturer Northrop Grumman.

Thusfar, the Navy had used a surrogate aircraft for AAR testing.

The service in June 2014 awarded a contract modification to Northrop Grumman for aerial refueling research, development, test and evaluation efforts at Naval Air Station Patuxent River in Maryland, Capt. Beau Duarte, the Navy’s X-47B program manager, wrote in an emailed statement.

“Those efforts include additional [aircraft carrier] detachments and AAR software coding through the remainder of this calendar year. If resources allow, the Navy may demonstrate autonomous engagement flight testing in fiscal year 2015,” he said.

He declined to comment further on the demonstration.

The X-47B is the Navy’s first carrier-based drone, capable of almost completely autonomous operations even as the ship moves throughout the seas. The stealthy, tailless aircraft can take off, conduct surveillance and land back on the carrier using a combination of algorithms and sensors that allow it to land on the runway with precision. It first showcased that ability in May 2013 during sea trials on the USS George H.W. Bush when it successfully completed its first touch-and-go and arrested landings.  

In August 2014, it returned to the carrier deck once again for its first cooperative flight with a manned aircraft. This time, it flew in pattern with an F-18 Hornet over the USS Theodore Roosevelt.

Navy officials on the program have long hoped to test the aircraft’s aerial refueling capability. However, there has not been enough funding over the past two years to make that happen.

Duarte in August told reporters that, if more money was made available, he would like to further explore autonomous aerial refueling.

Combining unmanned aircraft with AAR is a potentially game-changing technology, said Robert Martinage, former under secretary of the Navy and currently a senior fellow at the Center for Strategic and Budgetary Assessments.

“Unlike manned aircraft, where the pilots gets tired and fatigued, that's not the case for unmanned systems,” he said in an interview. “If you can refuel them in air, you potentially have ultra-long mission endurance measured in 20, 30, 40 hours or longer, which tactically and operationally opens up a range of new employment options and operational constructs."

The Navy and Northrop Grumman in 2012 conducted AAR tests with a surrogate aircraft — a Learjet equipped with “real or functional” equivalents of the X-47B’s light control processor, navigation and vision systems. The demonstrations simulated both boom/receptacle and probe-and-drogue refueling techniques, a Northrop Grumman news release said. However, because the surrogate aircraft was not outfitted with a refueling receptacle or probe, no fuel was exchanged.

“During a typical refueling event, the tanker operator or a mission operator on the ground commanded the Learjet to fly, in sequence, to each of the major positions associated with aerial refueling: the pre-tanking observation point off one wing of the tanker, the refueling contact position behind the tanker and the post-tanking ‘reform’ position off the other wing of the tanker,” the release said.

If the Navy moves forward with aerial refueling test flights using the X-47B, they will be conducted on land, a Navy spokeswoman told National Defense.

This news comes at a challenging time for the Unmanned Carrier-Launched Airborne Surveillance and Strike program, or UCLASS, the follow-on to the X-47B that will provide surveillance and strike capability to the carrier air wing. For years, officials within the Navy and in Congress have disputed whether the platform should be more heavily focused on intelligence-gathering or on striking targets.

Requirements currently favor a high-endurance drone instead of a stealthy one capable of carrying large amounts of weapons.

“The current trajectory for the Navy program was 14-plus hours of unrefueled endurance, which then forces you to compromise on payload as well as on signature reduction,” Martinage said. “If the aircraft is capable of air-to-air refueling, the argument in favor of really long unrefueled organic range — 14 hours plus — is weakened." 

Although the final UCLASS request for proposals was due this September, all action going forward was put on hold until the Pentagon completes a review of its entire intelligence, surveillance and reconnaissance portfolio.

According to the fiscal year 2015 National Defense Appropriation Act passed last week by the House, Congress will appropriate the full request of $403 million for UCLASS research and development, but only after the Pentagon completes its ISR review and presents its findings to the House and Senate. This report must contain a review of the UCLASS air vehicle requirements.

Congress also wants an additional report from the Navy that identifies the cost and performance tradeoffs it made on UCLASS — especially in regards to the air vehicle’s strike capability in a denied environment — and defines its acquisition strategy, including a cost and schedule baseline for the program.

That report must also address how the service derived its requirements for the composition and capability of the future carrier air wing, including how UCLASS and other future Navy platforms such as the F-35 and the EA-18G will perform together in an anti-access/area denial environment.

The secretary of the Navy is responsible for submitting this report at the same time the president submits his fiscal year 2017 budget, the bill stated.

It makes sense to pause and re-evaluate the program’s trajectory, said Martinage, who supports the NDAA’s language. UCLASS would be a redundant capability if developed as an ISR platform, as the Navy will be able to leverage the MQ-4C Triton for long-range surveillance, he added.

Proponents of the current UCLASS requirements have said because flying drones off an aircraft carrier is such new territory, it is prudent for the Navy to move slowly.

The goal of the program is not only to design and develop the UCLASS air vehicle and the command-and-control equipment and infrastructure needed to network it with the ship, but also to develop the system’s concept of operations, Rear Adm. Mat Winter, program executive officer for unmanned aviation and strike weapons, told reporters in August. He has often said that UCLASS will be able to grow from its initial capability to a more sophisticated one capable of operating in contested environments.

Shawn Brimley, executive vice president and director of studies at the Center for a New American Security, said that the Navy has already demonstrated the ability to build a high-end unmanned aerial system that can be integrated onto the carrier deck. What the service needs to focus on is creating an unmanned aircraft that projects power in high-threat environments, he said.

“It’s not as though … we want some sort of ‘Star Wars’ aircraft that is sort of in the realm of science fiction,” he said. “We have clearly made progress walking down this path. … I would like us to be a little more ambitious regarding what we can do.”

The Senate is expected to pass the NDAA before the end of the lame-duck session.

Topics: Aviation, Defense Department, DOD Budget, Robotics, Unmanned Air Vehicles