For the past two decades, General Atomics Aeronautical Systems' Predator and Reaper designs have loomed so large in the world of military unmanned air vehicles that they have become almost synonymous with the term “unmanned aircraft”. The systems lorded over the skies in Afghanistan and Iraq, where the US Air Force employed them in its counter-insurgency efforts. Along with Northrop Grumman’s RQ-4 Global Hawk, the remotely piloted aircraft (RPA) easily dominated much of the uncontested airspace over the combat zones.
But just as it seemed these frontline RPAs were poised to unseat the USAF’s roster of manned fighters, Kratos Defense and Security Solutions and the US Air Force Research Laboratory (AFRL) have set to work on a smaller UAV that could upset the balance once again. Just as larger UAVs came on the scene early in the new millennium to take pilots out of harm’s way, the AFRL plans to save unmanned assets worth millions of dollars by sending out miniaturised versions worth a maximum of $3 million a copy.
The Low-Cost, Attritable Strike UAS Demonstration (LCASD) is focused not only on lowering the price of the aircraft, but designing a faster, more survivable UAV for an increasingly contested airspace populated by more advanced surface-to-air missiles and peer adversary aircraft.
“The reason these are being sought after and the reason the government is so interested is because they’re designed to go into contested airspace,” says Jeff Herro, senior vice-president of business development for Kratos’s unmanned systems division. “Reapers are not designed for contested airspace, [they] never have been. In our world, they’d be called a target. That’s the reason, otherwise [the air force] wouldn’t be thinking about this.”
In July 2016, the AFRL awarded Kratos a $40 million research and development contract to develop the LCASD: a long-range, transonic, limited-life air vehicle. Parallel to the LCASD, AFRL and the Defense Advanced Research Projects Agency are funding the Gremlins programme. As part of the Defense Department's third offset initiative, the Gremlins concept imagines swarms of small UAVs launched from a variety of aircraft before in-flight recovery by a Lockheed C-130. Unlike the USAF’s Gremlins programme, which plans to launch and recover a swarm of unmanned assets from an aircraft, the LCASD will launch and recover its UAVs on the ground using Kratos’ rail launcher.
LCASD programme will leverage Kratos's experience with BQM-167 target drone
USAF
The service foresees a platform that could be upgraded with new technologies without waiting for major system upgrade cycles and which could provide high-speed strike capabilities in areas where forward-basing is difficult, according to the air force’s LCASD broad agency announcement. While the USAF has targeted a cost of $3 million per copy for the UAV, an order quantity of more than 100 could yield aircraft at $2 million each.
The programme achieved its preliminary design review (PDR) in early April and will move on to critical design review in "late summer." Craig Neslen, LCASD manufacturing lead at the AFRL, tells FlightGlobal that first flight is slated for the spring of 2018, although he admits that is an aggressive schedule for the air force.
During the PDR, the air force examined areas on the platform where the programme could take more risk and forgo some airworthiness requirements. Since the platform is attritable, the operator could ease the requirement for secondary load paths such as fasteners. But Kratos, which has built target drones for the USAF and US Navy, argues that it already saves money by easing its focus on the aircraft’s structure. Its popular target drone for the air force, the BQM-167, is made of composite carbon fiber and epoxy-based materials.
“Structurally, we don’t care,” Herro says. “We’re not putting multiple layers of redundancy on these airplanes. We don’t double up on everything. Whereas in other aircraft we would be: there’s redundancy on Global Hawk.”
The USAF’s basic requirements for LCASD call for a 227kg (500lb) payload, or the equivalent of two small diameter bombs (SDB), and a Mach 0.9 performance. The Kratos demonstration vehicle, dubbed the XQ-222 Valkyrie, is 9.1m (30ft) long and has a 6.7m (22ft) wingspan. That makes the LCASD smaller than a Boeing F-15, but larger than the company's biggest target drone system, the BQM-167, which measures 6m (20ft) in length and boasts a 3.2m (10.5ft) wingspan. The 82nd Aerial Targets Squadron operates the target drone for air-to-air weapon system evaluation programme at Tyndall Air Force Base, Florida.
Unlike the BQM-167, which is equipped with a Micro Turbo TR 60-5 Turbojet engine that lends 1,000 lb of thrust, Kratos has outfitted Valkyrie with a WJ-33 Turbofan engine packing 2,000 lb of thrust. The target drone can reach 0.92 Mach speeds, while current specification sheets peg the XQ-222 at 0.85 Mach with a maximum 4,500nm range.
The Valkyrie isn't just a disposable drone, its V-tails and internal weapons bays lend low-observable qualities to the aircraft. Kratos designed the new UAV with an internal payload that can carry more than the two SDBs the air force required. While Herro would not elaborate on the UAV’s stealth capability, he notes that Kratos has limited the radar cross section by keeping weapons carriage internal.
“You need the size anyway because of the range you’re going,” Herro says. Size enables internal carriage, which minimises drag, “so we can double the utility of the aircraft and stay inside that cost bogey you’re looking for”.
Although LCASD includes the word "strike" in its name, the air force is examining several missions for the low-cost asset, with a focus on it being an offboard weapons truck, with sensing and jamming. As an offboard weapons station, the UAV would carry SDBs and hold limited electro-optical/infrared sensing capabilities, along with full-motion video, Neslen says. Kratos sees LCASD as a one-configuration aircraft with several payloads that allow multi-mission capability; one aircraft, says Herro, could execute an electronic warfare and strike mission.
Under the USAF’s tactical offboard sensor programme, a small UAV would shoot out of a common launch tube on a Lockheed Martin AC-130. The UAVs would then serve as the gunship’s eyes in cloud cover and bad weather. The AFRL sees a similar opportunity for LCASD, although it is too large to fit inside the launch tube. Instead, an LCASD asset would fly about 100nm (185km) ahead of a command and control platform, such as the air force’s Boeing E-3 airborne early warning and control system aircraft. The manned asset would not control the UAV’s every movement, but could give commands to perform battle damage assessment or drop a bomb on a target, Neslen says.
“We’re looking at a sensor extension variant, so that could be used in co-ordination with some of our other aircraft radar platforms,” he says. “We could put these LCASD that have these additional sensing capabilities out in front of our current assets and they essentially pick up radar signatures, radar signals, and feed that back to our other assets.”
As part of LCASD’s cost-saving measures during the production phase, the AFRL plans to leverage non-traditional manufacturing processes from the automotive industry. It has not developed a comprehensive vision of its production process, but anticipates bringing in a low-cost rapid-cure composite resin system. This would cure in a matter of minutes, as opposed to hours in a large autoclave, Neslen says.
Although the popular view of “drones” depicts an autonomous vehicle killing from the skies, the more apt term for those aircraft is “remotely piloted”. Class 5 UAVs such as the Reaper must be operated by a pilot in a ground control station. The job is a mentally gruelling task, and the air force is struggling to recruit and maintain its RPA pilots.
Besides the changing operational picture, the air force moved toward small UAVs once it realised the service had a hit a plateau with its budget and manpower, Col Brandon Baker, USAF director of RPA capabilities, told reporters during the small UAS roadmap roll-out last spring. Unlike their remotely piloted predecessors, the small UAVs of the future would work as a force multiplier, he said.
“More importantly, they have a self-healing kind of context to it,” he said. “As opposed to a single platform with all the different capabilities on it, if that’s shot down it’s a 'one and done' scenario. We envision it can still achieve the objective with maybe even significant losses.”
When the USAF unveiled its small UAS roadmap in 2016, the service compared the price of several, smaller UAVs versus one enemy surface-to-air missile. Today, the air force employs one MQ-9 Reaper that hosts a suite of sensors, weapons and payloads. But a single MQ-9 unit, including four aircraft and ground control station, can cost $20 million, according to recent USAF estimates. That creates an easy cost calculation for the enemy, Baker said.
“We’re looking at $20 million for a Reaper, and the enemy has a pretty easy decision to make. Each shot they take off a surface-to-air missile is about $1 million. So it’s a 20 to one ratio and probably a pretty good ratio of kill,” he said. “That’s slanted toward our adversaries with that model.”
But the air force planned another way to defeat enemy air defences on both the battlefield and in the budget. The roadmap envisioned a team of small UAVs with disaggregated sensors which, if shot down, would represent a fraction of the financial loss of a disabled Reaper.
In order for that cost calculus to work in the USAF’s favour, however, the small UAVs must cost less than $1 million each.
Source: FlightGlobal.com
