Aircraft developers believe these five pieces of technology need to be improved to make attritable aircraft work.
Advanced manufacturing and engineering
Digital engineering will be key to balancing the cost and capability of attritable aircraft, before using funds for building prototypes and flight testing, says Shane Arnott, director of Boeing Australia’s Airpower Teaming System programme.
“For example, through application of digital engineering, Boeing Australia has a digital twin of the entire Boeing Airpower Teaming System aircraft design that we’ve been able to ‘fly’ thousands of times under different scenarios to test aircraft performance, the mission system and many other components necessary for capable attritable aircraft,” he says.
Moreover, tools such as additive manufacturing, autonomy in the fabrication plant and digital engineering, are needed to quicken the pace of innovation, says Scott Wierzbanowski, programme manager for the Defense Advanced Research Projects Agency’s (DARPA) X-61 Gremlins programme.
“Whereas it may typically take three to five years to build a clean sheet autonomous air vehicle, driving the build cycle down to 12 to 18 months not only regulates non-recurring costs, but also pushes cutting edge technology out to the field sooner,” he says.
Managing loyal wingman or swarms of attritable UAVs can’t add tasks to overworked pilots and ground operators. Instead, new forms of flight control automation and artificially intelligent software need to be developed.
“Scaling up quantities of deployed vehicles must be done in parallel with the reduction of the number of human operators required to control them,” says Tim Keeter, Dynetics X-61 Gremlins programme manager. “From force composition, to mission planning, to engagement, the commander’s intent needs to be clearly and simply communicated by the operator and autonomously implemented by artificially intelligent agents distributed throughout the system.”
Autonomy is also needed to cope when adversaries, such as Russia or China, use electronic warfare to jam or disrupt communication between operators and UAVs.
“Denied environments will stress these future systems to intelligently adapt when individual aircraft are lost, to identify new threats or changes in an adversary’s tactics, and to quickly fuse data from multiple, distributed sensors for consumption by the swarm, as well as by the human operator,” says Keeter.
Cheaper jet turbines
Because attritbale aircraft would likely only have lifecycles of 20 to 30 missions – more than single-use cruise missiles, but less than manned jet fighters – new turbines need to be developed to fit this novel application.
“The cost of engines in the 700lb-thrust and smaller class is a significant factor in the cost of an attritable vehicle. Lower vehicle costs promote greater use of attritable vehicles, which increases the demand for engine production,” says Keeter of Dynetics. “Additionally, engines that are optimized for reuse with quick refurbishment times as opposed to being expendable, offer a greater advantage for attritable vehicles that are also recoverable. Above all, a revisualisation of engine design to reduce parts count, materials, machining and touch labor costs that are achievable through additive manufacturing and new production technologies is key.”
Cheaper mission systems
For an attritable aircraft to be low-cost enough to be lost to combat attrition its subsystems and payloads also need to be inexpensive.
“There are certainly payloads that can fit the attritable price range, but many are at the lower end of the capability spectrum or are single-mode and capability systems,” says Steve Fendley, president of Kratos’s unmanned systems division. “There will likely be continued focus on producing mission payloads near the technical edge of the envelope, but with an objective for a significantly reduced cost, where even the high-capability payloads can be considered attritable.”
Another way to reduce costs would be to network and synthesise information gathered from inexpensive sensors across a group of UAVs, giving operators data without having to risk a single $5 million to $10 million multi-mode sensor, he says. “In this case, UAVs would be deployed in numbers and would work as integrated teams to satisfy the mission requirement,” says Fendley.
More work needs to be done to perfect recovering UAVs in midair, says Keeter of Dynetics.
“While most may struggle to think of airborne recoverability as a technology, it is in fact a collection of enabling technologies like precision navigation, innovative recovery systems, robust safety systems, aerial networks, mass property management, structural design elements to enable recovery, and specialized avionics,” he says. “Going the next step to attritable aircraft that are also recoverable allows vehicle costs to amortise across multiple uses, enables use of high-performance and high-cost payloads, and can significantly lower average mission cost.”