Driving factors, challenges in development of unmanned combat air vehicles
06:22 GMT, October 5, 2009 This article is to provide a review of the current status of UCAV (Unmanned Combat Air Vehicles) around the world, addressing both technological issues as well as operational implications. Having been published in one of the recent issues of MILITARY TECHNOLOGY, it is reproduced here as part of the current defpro.focus “Taking UAVs to the Next Level” which can be accessed here: http://www.defpro.com/focus/profile/uav/. To provide you a comprehensive but still clear overview, this article has been divided into two parts. Part 2 will be published at defpro.com on 7 October 2009.
With a few exceptions, the exponential growth in Unmanned Air Vehicles (UAV) or Unmanned Air Systems (UAS) is remarkable in that it is closely paralleling the rapid development of the aeroplane as a fighting machine in the early years of the 20th century. Then, as now, the first aerial war machines, were flimsy, slow, but provided a valuable capability in reconnaissance that was to change the way of warfare. Early warplanes, like early UAVs were used for artillery spotting (such as the US PIONEER and British PHOENIX UAVs) and battlefield surveillance. However, as the First World War progressed, pilots and observers began to arm their aircraft with grenades, flechettes and light bombs, to prosecute opportunity targets (or time-sensitive targets, TSTs, in today’s parlance) they saw below them. Today we have seen the emergence of the armed General Atomics PREDATOR, the REAPER/WARRIOR and UAVs like BAE Systems’ MANTIS and FURY with dual ISTAR/armed strike capability.
The next leap in technology is thus almost on us, and while the historical record shows that the next development was the scout, pursuit or fighting aircraft to deny the airspace to other enemy reconnaissance aircraft, for today’s unmanned aviation this is the UCAV - a dedicated air combat robot. Here the parallels start to diverge, in that the UCAVs now currently being developed are projected to have as their main mission strike and SEAD/DEAD (suppression/destruction of enemy air defences) roles, necessitating a low-observable stealth configuration. However it is instructive to remember that already air-to-air combat between manned aircraft and UAVs has occurred - when a US PREDATOR (equipped with a STINGER AAM) took on a MiG-25 FOXBAT in the run-up to the Iraq invasion of 2003; in 2006, when a Israeli Air Force F-16 shot down a Hezbollah UAV; in 2008, when a MiG-29 was captured on camera shooting down a Georgian HERMES 450 UAV; and recently when a USAF F-16 was reported to have shot down an Iranian drone in Iraqi airspace. In all these instances, the UAV came out the loser but given the historical evolution of the combat aircraft roles that unmanned aviation is closely following, it would be imprudent to bet that future generation of UCAVs do not take up some air-to-air mission eventually - and this might be sooner than people think, if as in the past, the white-hot crucible of conflict (either “cold” or “hot”) pushes technology faster than peacetime.
Why UCAVs?
A number of factors are driving the development of UCAV design and development around the world. Let us look at some of the main drivers.
• The “Body Bag Factor”
A clear driver in the growth of UAV operations is the removal of the so-called “body bag factor”. The loss of an airframe, though annoying (and possibly expensive) is nothing compared to a human life, or the introduction of aircrew as hostages in conflict situation.
The traditional danger by military pilots is being increased by the latest Russian and Chinese-developed triple-digit SAM air defence systems, (such as the S-300/400), now being widely exported. These highly lethal systems either mean that aircrews will face significant losses in degrading such networked AD systems (even if they are flying stealth aircraft), or other ways must be found. These can include network attack/and or jamming, or alternatively the use of UCAVs to penetrate the most dense and most dangerous parts of the air defence system to knock out key nodes and clear a path for manned strike aircraft.
• Autonomy
A second driver in the growth of UCAVs is the move towards more and more autonomous air vehicles. This, argue some, will result in fewer accidents as the piloting task is de-skilled and the UAV operator becomes a “supervisor”, with the majority of UAV losses now down to human error. But more importantly, some contend, is that bandwidth limitations will drive autonomy. Already the limited radio frequency spectrum is getting congested by existing UAVs - so in the future, there will not be the available bandwidth to remotely pilot a UCAV with an operator seated in a 360° dome with live colour TV fed from the vehicles sensors (And this is when you don’t even consider the possibility of lost communications or deliberate jamming). There will therefore have to be more autonomous and more “intelligent” vehicles if UAVs will attempt to undertake these new highly complex mission sets like SEAD or strike.
• New Capabilities
UCAVs also promise to endow air forces with new revolutionary capabilities. Persistence, for example, is already a major selling point for UAVs operating over Afghanistan and which allows them to “stare” at the battlespace for time-sensitive targets and to gather intelligence on patterns of life. However, the next generation of UCAVs will take this further, as they will add high-speed, air-to-air refuelling, broadband stealth and even directed energy weapons to the mix, potentially ushering in a new chapter in aerial warfare.
High speed, currently lacking in today’s armed UAVs, will enable UCAVs to get to the fight quickly when needed. Meanwhile air-to-air refuelling (either from buddy UCAVs or from manned tankers) will enable the UCAV to loiter for even longer in the skies - and unencumbered by pilot fatigue, might in the end, only be limited by MTBF (Mean Time Before Failures) values on components and/or reserves of hydraulics or battery power. In broadband stealth too, UCAVs thanks to the removal of the pilot, can be made smaller and have a lower radar-cross section thanks too their reduced vertical profile than comparably sized manned combat aircraft. Finally, the growing field of directed energy weapons (DEW) such as microwaves and lasers could be a natural fit for UCAVs, especially in that such high-power microwave weapons could pose issues in integrating them in a manned aircraft without literally frying the pilot). Indeed the UK’s RAF has already indicated that it is extremely interested in this line of development.
• More Challenging Threat Environments
Yet another factor in the development of UCAVs is the growing capabilities and effectiveness to be expected by future air defence networks, including not only SAMs but fighter aircraft as well. While the “body bag” argument has already been discussed above, the current generation of armed UAVs such as REAPER and MANTIS, can only be really used in highly permissive environments, where a SEAD campaign had already destroyed or rendered impotent air defences. However, in the future, an Afghan- or Iraqi-style uncontested airspace may not be the norm. As one senior RAF source notes, “At the moment we are engaged in operations in uncontested airspace - but it will be prudent to assume that future environments will not be benign.” It is also instructive to note that the RAF considers the REAPER UAV a high value asset - and thus a platform that, despite the lack of pilot, would not wish to lose easily.
Dedicated UCAVs with low-observable features and arguably self-defence capabilities will be the only way forward to penetrate, survive and indeed carry out any kind of mission in these highly lethal air defence networks in the future.
Challenges
It is however to be remembered that UCAV development is still very much in the early days and there remain a number of significant challenges to be overcome.
• Where to Test?
While there is nowadays a broader acceptance among aviation authorities and regulators of the potential uses of UAVs within the civil airspace, and thus a willingness to work with manufacturers, test centres and militaries to allow workable solutions for flight testing, until very recently these UAVs have all been unarmed. The new UCAVs will be faster, heavier, more autonomous, and crucially carry weapons. How will regulators satisfy concerns that a UCAV won’t go rogue or attack its makers? Though this seems like science fiction, the concerns are real and could delay or derail UCAV programmes if regulatory authorities cannot be convinced that the system will be safe transiting to and from or operating in standard military ranges.
• Is AI Really Up to It?
A second challenge is the artificial intelligence (AI) feature for autonomous operations. While the simple autopilot has been around almost as long as manned aviation, and computers continue to grow in power and capability, the more one moves up the scale of mission complexity from reconnaissance, to strike, to SEAD, to air combat, the more variables come into play and the more human instinct, training and experience (or a passable simulation thereof) may be needed. A UCAV on a SEAD mission, for example, might be programmed to recognise, evade and destroy SAM sites, but would it have the “gut instinct” of a veteran Wild Weasel pilot that a certain radar site was a trap?
• Legal/Ethical Ramifications
Another potential issue as these vehicles become more autonomous is the legal and ethical implications. While some argue that these issues have been around for a considerable period of time (for instance the contact sea mine which waits for a ship to explode), the emphasis today on proportionality and reducing collateral damage and loss of life (not only to civilians but even to enemy combatants) means that the technology is again racing ahead of the laws of war. Up to now this has been dealt with by keeping a man in the loop who controls and gives the final say when a weapon is released. However, in the future, it is could be perfectly feasible to envisage a state allowing UCAVs to be “unleashed” due to a dire conflict situation, or a desire to use the edge autonomy could give (never needs to sleep, and can react in nano-seconds) to beat a peer competitor armed with similar weapons. So, will the rules of armed conflict need to be rewritten?
• Expenses
Cost is another emerging challenge. While UAVs were originally marketed to the world’s militaries as being effectively disposable (and this would still apply to mini and micro-UAVs), the high cost of the sensors installed on admittedly relatively cheap airframes continues to push the final price tags higher and higher. The intrinsic intelligence worth of these platforms, too, means that at least some of them must be thought of as high-value assets. And as these platforms take on new roles, such as armed recce and close air support, and at the same time need to fly in civilian airspace (thus perhaps needing two engines, triple redundant flight controls and a sense-and-avoid system) the costs will go further up.
For a UCAV then, which would incorporate the latest sensors, stealth or low observable features, and possibly a novel directed energy weapon, it is not clear how affordable this might be compared to a modern manned fighter. It may be that a first generation stealth UCAV could in fact exceed the cost of a legacy, non-stealthy fighter that has been upgraded with the latest radar and weapons.
• Culture
Finally there is perhaps the most difficult obstacle to overcome - leaving behind nearly a century of air force’s culture and traditions, which see the pilot as the central actor in air combat. Indeed the “rise of the machines” has already been predicted once, in the infamous 1957 Sandys White Paper in the UK, which over-optimistically foresaw the end of manned fighters and wholesale adoption of missile technology. The public, too, conditioned by films such as “Terminator”, “2001 - A Space Odyssey” or the “Star Wars” series is also naturally distrustful of “intelligent” machines taking over. For instance, despite autopilots and advanced flight management systems in today’s glass-cockpit airliners which control the flight almost from beginning to end, the majority of passengers would be markedly reluctant to fly in a pilotless aircraft, even if told that the elimination of human error might actually result in a safer aircraft. On the other hand, when lifts and elevators where first introduced they had to be operated by their own “pilot”, but the public has since learned to thrust automated operations.
So, will air forces be able and willing to turn their back on the “mounted knight” of our age, the fighter pilot? And, will public opinion let them do so? The answer to the first question seems to be moving towards “yes”, at least as regards certain high-risk air-to-ground missions pilots never really liked (and for reason). ´The second aspect, however, might well prove a rather tough nut to crack.
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By Tim Robinson
The author, Tim Robinson, is Deputy Editor at the Royal Aeronautical Society’s “Aerospace International”.
Military Technology (MILTECH)
