Issue 346: Unmanned and Over here?

Right now such a long-ranging UCAV able to operate in contested airspace doesn’t exist (at least not one that is publicly known about), but the technology to build one certainly does, thanks to the US Navy’s UCAS-D – Unmanned Combat Air System – Demonstration – program.

UCAS-D saw Northrop Grumman build and fly two X-47B UCAV demonstrators which successfully validated the ability of a tail-less UAV to land and takeoff from an aircraft carrier, integrate into normal aircraft carrier operations, and to conduct aerial refuelling.

“It isn’t very often you get a glimpse of the future. Today, those of us aboard USS George H W Bush got that chance as we witnessed the X-47B make its first ever arrested landing aboard an aircraft carrier,” then Secretary of the Navy Ray Mabus said of the X-47B’s first arrested carrier landing, on July 10 2013.

“The operational unmanned aircraft soon to be developed have the opportunity to radically change the way presence and combat power are delivered from our aircraft carriers.”

Landing on an aircraft carrier is known to be one of the most stressful and challenging tasks a [human] pilot undertakes.

But according to Northrop Grumman’s Rear Admiral (ret’d) Tim Beard, a former US Navy A-4 Skyhawk and A-6 Intruder pilot and commanding officer of the carrier USS John F Kennedy. “The X-47B’s landing accuracy is “pretty amazing for a guy who flew airplanes. It’s most comforting.”

“Go watch an F-35 or F-18 coming aboard, you’ll see tails moving and the pilot working really hard to get her aboard,” Scott Winship, Northrop Grumman’s vice president of advanced warfare development, said.

“That’s a three hertz versus a 100 hertz brain. The airplane knows immediately when it’s off and corrects, all the way, a lot of tiny corrections versus relatively large corrections.”

The significance of the achievement of an unmanned aircraft landing on an aircraft carrier was recognised by the US National Aeronautic Association awarding the US Navy-Northrop Grumman X-47B team received the highly prestigious Robert J Collier Trophy for 2013 “…for developing and demonstrating the first unmanned, autonomous air system operating from an aircraft carrier.”

And that award was presented before the X-47B successfully demonstrated its ability to refuel inflight from a 707 tanker, during trials off the Maryland coast in April 2015 – an achievement that Beard said was perhaps greater than landing on a carrier.

“The amount of programming and the amount of precision it took to be able to find, track a tanker, position yourself and follow it, then get a visual on the drogue, then close and integrate to that (drogue’s) circle, get in position 10ft behind, close to get gas, come back straight away so you don’t ‘hang up’ and get away from it, that is collectively a harder problem.”

While a human pilot’s heart rate will be higher during a carrier landing than during aerial refuelling, the precision required for the X-47B to connect to tanker meant “those guys executed magic,” Beard, Northrop Grumman’s program manager, advanced air warfare, said.

“It’s a combination of electrooptical vision transposed into to ‘ones and zeros’ to make that thing do that, then the engine has to respond and the airplane has to respond perfectly, and then you have to take fuel, because there are switches in the system that allow you to take the fuel.

“When those guys pulled it off I was like ‘wow, that’s really something!’. I was pretty giddy when they landed it on the ship for the first time too!” So why test unmanned refuelling? “This is what unlocks the true potential of an unmanned system, we can keep it in the air for an extended period of time,” Winship said. To date, unmanned aircraft have required slender long wings and fuel efficient turboprop or business jet

This is what unlocks the true potential of an unmanned system. SCOTT WINSHIP

turbofan engines to give them their extended endurance.

“Once you solve the refuelling problem you allow the design of the jet to be what it needs to be for the mission, she can be anything she needs to be,” Winship said.

Aerial refuelling, therefore, marks a watershed in the design of unmanned combat aircraft.

“All unmanned airplanes started off trying to be as fuel-efficient as they could be with the tank of gas that they were given. That lead to Global Hawk designs, she’s great at what she does. But when you start refuelling them, now you’ve unlocked the design potential of the airplane, along with the persistence.”

Further, not having to design an aircraft to carry as much fuel as possible means it can carry more systems, sensors and weapons, or go faster.

With refuelling what then becomes the limit on aircraft endurance is not oil, but systems like APUs and actuators are all designed to run for a certain amount of time, An actuator, for example, has to be visually inspected about every 50 hours, and designing actuators for a 100 hour or 200 hour service interval would involved expensive non recurring engineering costs.

“So we wanted to try and find, what can we do with a 50-hour airplane,” Beard said. “We didn’t want to have to spend a whole bunch of money trying to redesign everything.”

That “50-hour airplane” currently doesn’t exist, although Northrop Grumman had planned to offer a larger development of the X-47B for the US Navy’s Unmanned Carrier- Launched Airborne Surveillance and Strike (UCLASS) program, which was intended to field an operational UCAV as a follow-on from UCAS-D.

Within the US Government and Department of Defense the UCLASS program became something of a football as different vested interests argued over the required performance requirements and cost – would it be a long-range strike aircraft or a long endurance surveillance platform? For now it looks like the longrange strike potential of a carrierbased UCAV will have to wait, as in February 2016 the Navy replaced the UCLASS program with its requirement for a Carrier-Based Aerial Refuelling System (CBARS) unmanned aircraft instead. This would be an unmanned air-to-air refuelling tanker with a limited ISR and strike mission that will primarily free up F/A-18E Super Hornets currently undertaking the carrier-based ‘buddy tanker’ role.

Northrop Grumman is one of four US defence contractors awarded concept definition contracts for what will be called the MQ-25 Stingray, along with Boeing, General Atomics and Lockheed Martin (all of which were also contending for the UCLASS program), a platform that will be optimised for aerial refuelling with surveillance and strike as secondary duties.

“We’re probably going to drop some of the high-end specs and try to grow the class and increase the survivability [later],” the US Navy’s deputy chief of naval operations for integration of capabilities and resources Vice Admiral Joseph Mulloy, told USNI News in February 2016.

“It has to be more refuelling, a little bit of ISR, weapons later and focus on its ability to be the flying truck.”

That flying truck will be able to extend the reach of carrier-based Super Hornets and F-35Cs so they can strike targets beyond the reach of the China’s so-called “carrier-killer” DF-21D antiship ballistic missile with its 1,000nm range.

Like any aircraft design, the Stingray design will be the result of different trade-offs.

“Decks are getting full, spot factor available for Stingray is minimal. So the challenge is to find an optimal spot factor and a enough of them to be able to get the air wing as far as possible,” Northrop Grumman’s Beard explained.

“It isn’t that we’ve have the right answer, it is that we’ve got some experience into what the range, payload, service ceiling, flight speed payoff is, what that matrix looks like.”

For now with the Stingray program replacing UCLASS it looks like a carrier-based deep strike UCAV is some years off, but in the meantime Northrop Grumman continues to proselytise on the benefits of a UCAV.

“This technology is here, I could make you an operational one of these.

Now is it built into the culture yet, is it built into our infrastructure – no. But the technology is here,” says Winship.

To highlight the benefits of that technology Northrop Grumman has shown RAAF and Department of Defence officials modelling of how using aerial refuelling a package of six upsized X-47Bs – a notional aircraft slightly bigger than today’s Super Hornet with a 1,500nm range and eight-10 hour endurance – could provide persistent surveillance and strike over 2,200nm from an Australian air base.

This technology is here, I could make you an operational one of these. SCOTT WINSHIP

“For six airplanes you can get two hours per airplane over target and with a 90 per cent availability rate you can sustain this for a couple of days,” Beard said.

Such a UCAV could use the F-35’s radar and have a weapons bay “the exact same size” as an F-35’s,” he said. Such a UCAV could also have potential in air-to-air combat.

“Send it out with an F-35, with one on either side or two on either side and the F-35 is radiating and it’s picking out the targets, designating and whomever is coming at it doesn’t know there’s two or four (UCAVs) out there with six to eight AMRAAMs in each airplane,” said Beard.

Then there are UCAVs nonoperational benefits they don’t have to be flown for pilots to maintain currency.

“If you don’t have to train and maintain pilots you don’t have to wear out airplanes to train with. The cost savings are staggering,” said Winship.

Instead, UCAV pilots (or air vehicle operators) and sensor operators can train using emulation modes in their ground control stations.

Even more importantly, UCAVs they can fly into contested airspace without putting a pilot’s life at risk, and without the need to mount a costly and risky CSAR (combat search and rescue) mission should one be shot down.

Still, despite their promise, an operational UCAV seems some years off yet. France (Dassault Neuron), the UK (BAE Systems Taranis) and China (AVIC Cloud Shadow) have all developed UCAV technology demonstrators, showing that it is not just the US that sees their potential. But if not technological then cultural and budgetary barriers remain.

Nonetheless, Northrop Grumman’s Winship is upbeat.

“We’re finally getting to the point where the need for these kinds of things is showing itself, where range is a problem for the aircraft carrier, range is a problem for the United States Air Force from Hawaii or Guam, and we have to get to the point where ok do we have a solution for that and we’re going through our internal analsys of alternatives for all those,” Winship said.

“This is a glimpse at a future state that I think is getting pretty close to us.”