Indian Defence Review

Various Unmanned Aerial Vehicles. Pictured are (front to back, left to right) RQ-11A Raven, Evolution, Dragon Eye, NASA FLIC, Arcturus T-15, Skylark, Tern, RQ-2B Pioneer, and Neptune.

At the basic level, Unmanned Aerial Combat Vehicles (UACV) differ from manned fighters only in that control of mission execution is done remotely in the former and from within the vehicle by humans in the latter. The degree of control of UAVs could extend all the way from total robotic control of decision making and mission execution by artificial intelligence to limited control of mission parameters by either artificial intelligence or remote human operators or a combination of both. Total robotic control is still in the future. This future could be as close as two decades or so away since the basic concepts and technologies are rapidly being validated.

Fifty years ago, such a comparison would have been an exercise in crystal gazing. In the mid-1960s, many of the technologies of warfare that exist today were already operationally deployed by the advanced military powers. Satellite reconnaissance and thermonuclear strike capabilities using the triad of land-based ICBMs, submarine-based missiles and manned bombers were in place. The complementary technologies of air-to-air refueling, Airborne Early Warning & Control Systems (AWACS) and Airborne Electronic Warfare (AEW) systems were operational and first-generation Precision Guided Munitions (PGMs) were entering service. Target drones and air-to-ground missiles were being modified to fly pre-programmed profiles on autopilot to serve as radar decoys and to probe enemy air defences. However, the real advent of Unmanned Aerial Vehicles (UAVs) as we know them today, had to wait for a few more years.

An indicator of the exponential advances in the field of technology in the last 25 years is that UAVs have now become an integral part of the military inventories of almost all modern military powers. In the evolution of warfare, the human element is being replaced in the weapons delivery phase by intelligent machines. The world is now at the threshold of an era where some form of robotics coupled with artificial intelligence is making inroads into the decision-making processes of command and control. This shift will undoubtedly change the paradigms of planning and execution of warfare in the future.

Evolution of the UAV

Three decades or so ago, the main constraint to this development was one of technology. Advances in a few key fields had to precede the transformation from concept to operational reality. UAVs probably had their start in miniature flying models. These were initially guided by cables and once radio control technology progressed, by remote control. Autopilots were added to enable a rudimentary robotic control for simple profiles. Advances in miniaturisation of all components were needed to increase the capabilities of the platform of a given size. Cameras of increasing sophistication were soon added as payloads followed by other passive and active sensors. Digital communication for real time data transfer followed. To manage increasingly complex tasks, high speed data processing became necessary and this had to wait for developments in computer processing. The next step was weaponisation of the platform.

At present, the UAV is used primarily as a sensor platform for surveillance and reconnaissance. Weaponised UAVs for air-to-surface weapons delivery are also operationally deployed. UAVs now have a degree of independent operation but are primarily remotely controlled by the human element. Decision making is solely by the human element in the control loop. Most of the UAVs deployed are optimised as some form of sensor platforms. The weaponised ones are just launch platforms with only the weapons themselves having the attributes of high speed and agility in order to survive in the face of enemy defenses till they impact their targets.

Technology

Some of the key areas of advances in technology that have been essential for development of UAVs need to be elaborated upon in slightly greater detail. A majority of these have progressed from laboratory concepts to deployable systems in the last three decades or so.

Remote Control

The transformation of the UAV from a hobby gadget to a powerful military tool was made possible only when the requirement of being physically connected to the operator was removed. Remote radio control achieved this and extended the range of controlled flight to the limits of radio range. Advances in control technology and advent of digital communication resulted in the ability of the operator to remotely control the UAV with inputs similar to those used for controlling conventional aircraft. Limitations of radio range were overcome by using more powerful trans-receivers, airborne relay platforms and eventually space-based satellites for global coverage. Mission profiles could be split up into various segments such as launch, transit, the operational phase and recovery – all capable of being handled by different operators at different locations. This also kept the human element well out of harm’s way. One danger is that remote control channels can be interfered with leading to the whole mission being compromised.

Robotics & Automation

Robotics in aviation has been with us from the autopilots predating World War II. Autopilots in manned aircraft now handle most flight profiles for commercial flights, the flight plans themselves being digitally generated by computers. In military aviation, weapons delivery profiles as also recoveries and landings, even on aircraft carriers, have been automated. In conjunction with computers, robots can be preprogrammed for complex tasks. They already have rudimentary reasoning and logical deductive powers. Robotic control of motor vehicles in crowded traffic is a reality at least in trials. UAVs of the future will rely on robotic control to achieve truly independent operation without human intervention.

Miniaturisation

Miniaturisation has always been a key element in aviation technology. The cavity magnetron, which is at the heart of all domestic microwave ovens, was developed during World War II and transformed the radar from a huge unwieldy ground-based apparatus to a portable device that could be fitted on ships and aircraft. It was an important force multiplier in winning the battle of the Atlantic. Similar advances in control and power systems, communications and sensors have been crucial in making UAVs viable. A simple example of the advances in miniaturisation is that of the average smart phone which packs the capabilities of a personal computer, an audio visual entertainment system, a radio trans receiver, a satellite location and navigation tool, a power source and many other devices into a small instrument weighing less than 150 gm.

Sensors

Advances in sensor technology have made light-weight digital sensor packages having far greater capabilities than older analogue systems a reality. They have also become far more rugged than older systems, require little maintenance and have the capabilities of gathering, processing and forwarding data in near real time, a crucial attribute in modern conflict situations. In fact the problem is now one of information overload since the large volumes of data produced within such a short time frame cannot be digested easily. Increasing use of digital sensors, however, brings in the danger of hacking into the systems to corrupt or destroy data or to feed in false data.

Digital Communications

All of the above capabilities will only be of academic interest unless information reaches the decision maker in time. High speed digital data transfer between machines themselves, machines to operators and between operators or decision makers at different locations is now common. The danger is that communications are vulnerable to interception, interference and jamming.

Computational Power

The whole technology of modern UAVs and in fact, all modern machines be they cars, ships, planes, satellites, engines and control systems, are heavily dependent on computers. They are the brains of the system. Their accuracy and capacity to process data rapidly determines how well the system functions. Miniaturisation of components such as memory chips and transistors had to be first developed through new manufacturing processes before powerful computers of small size, low power consumption and rugged construction could be made. Advances in programming languages have also boosted hardware capabilities. This has been possible in the last 20 years or so. Again taking the example of an average smart phone, this has more processing power than the on board computers used in the lunar landing module of the Apollo manned mission to the moon in 1969.

Precision Guided Munitions (PGMs)

PGMs or smart weapons were earlier considered as exotic weapons to be used only against high value targets embedded in areas covered by sophisticated Air Defence (AD) systems. With increasing effectiveness of AD systems, their expanding lethal envelopes and high costs of aircraft plus reduced numbers available in inventories of air forces, unguided weapons with large errors are no longer the prime weapons of choice. Some form of post-launch guidance and increased stand-off ranges have become the norm.

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For UAVs, which as of now are more vulnerable to AD weapons and have limitations on payload, PGMs are perhaps the only effective weapon type. They are now being used not only against high value targets but even against individual insurgents on foot or in small vehicles. At times, the cost of the mission is greater than the annual revenue of the whole province where the target is located!

Rustom H

Comparisons

At the basic level, Unmanned Aerial Combat Vehicles (UCAV) differ from manned fighters only in that control of mission execution is done remotely in the former and from within the vehicle by humans in the latter. The degree of control of UAVs could extend all the way from total robotic control of decision making and mission execution by artificial intelligence to limited control of mission parameters by either artificial intelligence or remote human operators or a combination of both. Total robotic control is still in the future. This future could be as close as two decades or so away since the basic concepts and technologies are rapidly being validated.

The first operational roles of UAVs were surveillance, reconnaissance, communications relay and information gathering. Sizes of existing UAVs range from man-portable devices weighing a few kilogrammes to those comparable to fairly large manned aircraft. Some of the areas of comparison are listed below:

Size and Payload

Small UAVs are used to collects inputs at the micro level to see around the corner or to look beyond the next hill. In this role, they are far more effective in terms of cost, response time and ease of operation as compared to manned aircraft. They provide small groups of troops with an organic capability for surveillance, reconnaissance and data relay which otherwise would have to be provided by remote assets under the control of larger formations, at times out of touch with the local tactical picture. This advantage is often a game changer in low level conflicts like anti-insurgency and urban anti-terror operations, for both of which bigger manned aircraft are unsuitable and frequently unavailable. This advantage reduces as the size of the UAV increases as while they gain some of the advantages of larger manned aircraft, they inherit all the disadvantages.

Manned aircraft, on the other hand, have to be of a certain minimum size to cater for the onboard crew and associated support systems and safety features. These increase costs and complexity while admittedly giving more mission flexibility. As far as payloads go, even the biggest UAVs in service can carry weapons or sensors of lesser weight than the typical fighter aircraft.

Flight Performance

Most of the current generation medium and large UAVs have airframes and engines optimised for Medium Altitude Long Endurance (MALE) and High Altitude Long Range (HALE) surveillance roles. Low subsonic speed airframes for medium and high altitudes need large wings with low wing loading. Power plants aim for low fuel consumption with power output enough for flight at low subsonic speeds without much reserves of power for rapid acceleration or for rapid flight path changes which are essential requirements for manned aircraft in air combat. The result is airframes of low subsonic speeds, limited agility with less powerful propeller-driven turbine engines or fuel efficient turbofan jet engines. Agility and high speeds are secondary to endurance of up to 24 hours plus and flight ceilings of up to 18 to 20 km.

Landing in gusty wind conditions creates problems and large wingspans require lots of clearance for safe ground operations which requires regular runways. Transit times to reach target areas increase. The smaller class of UAVs designed for altitudes of operation up to around three kilometres and endurance of a couple of hours are less affected but are again limited by slow speeds. In the weapons delivery role, these deficiencies become critical in a hostile AD environment and in the air combat role they are not acceptable. Manned aircraft are usually either optimised for long endurance and high altitude or for acceleration, speed and agility. Many are multi-role capable. In terms of endurance, the larger UAVs come out ahead.

Onboard Systems

Small UAVs for local area surveillance can make do with optical sensors enhanced at most with night or thermal imaging capability with low resolutions, coupled with slower speed data links. Since onboard crew requirements do not exist, they can be small in size with a greater proportion of payload to total weight. The bigger UAVs operating at greater altitudes need more sophisticated sensors and links which add to payload weight, necessitating bigger platforms. However, the weight savings advantages of being unmanned still exist. Both the manned and unmanned platforms need similar sensors and equipment for similar tasks, be they surveillance or weapons delivery. Unmanned platforms can do with fewer redundancies in critical flight and engine systems since crew safety is not an issue.

Stealth Characteristics

The standard medium and big UAVs have poor stealth characteristics since designs for endurance are usually at variance with stealth requirements, This may be acceptable in low AD threat scenarios where the bulk of UAV combat operations have been conducted till now. The newer generation of truly combat optimised UAVs such as the British Taranis, numerous US designs including the carrier-capable X 47B, Russian, French and Chinese drones and the Indian Aura concept are being designed with stealth features and are in various stages of development. Incorporation of these features will degrade some other performance attributes as is often the case in aircraft design.

Vulnerability

Ultimately a weapons platform has to survive in combat at least till it delivers its weapons. Small low altitude UAVs are vulnerable to all ground-based light weapons but can get some protection by using terrain and because of their small size. They are difficult targets for high speed manned aircraft. However, the newer attack helicopters have the capability to counter them. The MALE and HALE UAVs rely only on long stand-off ranges and high altitudes for protection along with passive decoys and active jammers. If they are restricted to long ranges for weapons delivery, the weapons will have to be bigger and more complex. The present generation of bigger UAVs may not be viable in hostile airspace within the lethal envelopes of modern AD weapons.

Costs and Infrastructure

Smaller UAVs are more cost effective than even light manned aircraft in their limited field of operations. They are replacing manned aircraft in low level tactical reconnaissance, target designation and artillery fire control. In some air-to-ground weapons delivery scenarios in low threat areas, bigger UAVs have taken over from manned aircraft. As UAVs become more versatile, their complexity increases and the costs become comparable to those of manned aircraft. While smaller UAVs require minimal ground handling infrastructure, the bigger ones need as much infrastructure and ground support as manned aircraft with requirements of more sophisticated and hardened data links than the latter. UAVs are certainly not a solution to spiraling aircraft costs and infrastructure requirements.

Factors Influencing Combat Use

The United States Air Force is increasing its number of UAV operators to meet the ever growing demands of its fleet and in 2012 more drone pilots were trained than jet fighter and bomber pilots. Air-to-ground strike in low threat AD situations is becoming a UAV preserve. Unwillingness to risk pilots flying manned aircraft and plausible deniability are major factors in this change. It appears that just as the concept of “boots on the ground” is acceptable as long as the boots belong to proxies, UAV combat operations remotely controlled from home bases are becoming acceptable to the military and political leadership of the major powers.

Most inhibitions about remotely controlled warfare have already been swept aside. As UAVs with performance characteristics similar to manned fighters join the fleet, they will intrude into the field of air combat, the existing preserve of manned fighters. Enabling robots with artificial intelligence including reasoning and decision making ability is now more of ethics than technological feasibility. The latter already exists.

The Near Future

UAV development now is aimed at fielding fully combat capable robotic drones for air-to-ground and air-to-air combat in the near future. A UAV variant of the F-16 is already flying. This has the full combat capabilities of the manned fighter. The US Navy’s X 47B UAV with Catapult Assisted Take Off and Barrier Arrested Recovery (CATOBAR) capabilities is already engaged in integrated trials of aircraft carrier operations alongside manned fighters. A proposal to have a drone F-35 Joint Strike Fighter is on the cards. Supersonic stealth UAVs such as the British Taranis have already done initial flight trials with a planned induction by 2030. A concept has been mooted for developing a robotic computer controlled drone fighter which will be capable of taking on adversaries in the classic close range dogfight scenario, probably the last exclusive domain of the fighter pilot. It is claimed that computer hardware and software now have the capabilities to provide full situational awareness and to intelligently decide on and execute manoeuvres to gain a positional advantage in the shortest possible time.

As far as our situation is concerned, we are just stepping into the weaponised UAV stage. We do not yet have a HALE category UAV. Most of our higher performance UAVs are imported in contrast to China which is among the front runners of indigenous UAV development. We still have a long way to go. This is frontier technology and we may have to develop parts of it in house as was done for our nuclear weapons and ballistic missile projects. We cannot afford to miss the bus in this field especially with the prohibitive costs of aircraft, our constantly depleting force levels and the capabilities of those in the neighborhood as far as conventional and asymmetric irregular conflicts are concerned.