Indian Defence Review

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.