Loitering munition


India’s unmanned combat vehicles  

For India it took decades of trial and error and competence building on manned target training aircraft to transit to pilotless target trainers to unmanned aerial vehicles. And now India is preparing to deploy indigenous unmanned combat vehicles that will largely close the gap that exists between the country and the leaders in the technology.

Those in contact with the Defence Research and Development Organisation since its conversion from the Defence Science Laboratory were afflicted with a mixture of consternation and a feeling of accomplishment as the transition from manned flights of target aircraft to jet assisted takeoffs on imported JATO (jet assisted take off) bottles finally led to the successful flight of the first pilotless training aircraft.

Since then progress has been achieved through projects that accumulated technological proficiency step by step from the Lakshya pilotless target aircraft through Rustom-I and Rustom-2, as per the qualitative staff requirements of the army, navy and air force.

Their need for vehicles that could operate at different altitudes and durations led to rudimentary developments of low-level, medium altitude long endurance (MALE) and high altitude long endurance (HALE) prototypes while the operational requirements of the three services were catered to by imports of Israeli Searcher I and Searcher II that have been with the armed forces for about a decade. More recently the Heron has also been contracted for. The unique selling point of the Israeli UAVs is that they are the products of one of the world leaders in the technology and that these are proven platforms in combat situations.

Modern variants

One benchmark of incremental growth can be discerned from the power plants utilized in the first two variants of the UAV-the Rustom I has one Lycoming engine producing 150 horsepower whereas the Rustom-2 is powered by two Saturn engines that give a cumulative thrust of 200 horsepower. The Rustom-1 is a medium altitude long endurance (MALE) vehicle whereas the Rustom-2 and its derivative the Rustom-H are high altitude (HALEs).

The payload of instruments that can be carried for surveillance, electronic eavesdropping and artillery targeting has risen from 95 kg to 350 kg and between them they cater to operations between 26,000 ft and 35,000 ft, which is out of range of any small arms fire from ground troops.

To be able to shoot these down the enemy will have to deploy its fighter aircraft which is an activity that could be picked up by the drones well before the opposition can arrive on the scene. Counter-measures could be applied. Endurance ranges from 12 hours to 24 hours which facilitates the possibility of keeping a 24X7 vigil on particular stretches of the border areas through a relay arrangement of MALE and HALE vehicles.

The general drift of the UAV/unmanned combat aerial vehicle narrative in India is that its scientists are trying to emulate the manner in which the US managed to convert its redoubtable Predator drone into a kill machine that can deliver a warhead with high precision on target. While the general transition could be a copycat act, the range, accuracy and endurance is the product of onboard sensors which India will have to replicate if it is to achieve similar results.

While the megapixels of imagery produced by the Indian drones gives a clear picture of the target area and surveillance zones, there is room for improvement. The collateral benefits of indigenous development and deployment of such surveillance/weapons platforms is that the nation and the armed forces get to utilize to the full the economies of scale as well as the assured time on station that ancillary industries can contribute to by indigenous spare parts production.

While Israel is one of the largest exporters of weapons and military platforms to India some experiences as with the delay in repairing the damaged aerostats procured from that country cannot be ignored.

Robust engine

Giving credence to the truism that it is around an engine that the machine is made, India is taking steps to utilize the indigenous Kaveri engine that was constructed to power the indigenous Tejas light combat aircraft on homemade unmanned aerial vehicles for both surveillance and combat. While it is still unclear whether an “indigenous” Indian light combat aircraft will ever be powered by an Indian engine, the nation should be grateful that the Kaveri engine is not a total loss. It could still power the same number of UAVs or more than what was planned for it in the Tejas project.

Several laboratories of the Defence Research and Development Organisation are currently working on what is described as an Autonomous Unmanned Research Aircraft (AURA) which is to have stealth features and will be powered by the Kaveri engine. The all-up weight of the proposed combat vehicle will be about 15 tonnes. This is a measure of the inherent thrust capability of the Kaveri engine.

If the design is such that the thrust to weight ratio enables the engine to give adequate power to produce an aircraft that is both swift and agile, that is what constitutes a successful project. In the Tejas project the Kaveri engine could not produce the thrust that could carry both the aircraft and its weapons and fuel load. Even the American General Electric engine that was used to “prove the systems” could not be effective. It too had to be replaced by a more powerful engine.

Based on a robust engine the AURA will have rail-launching for the missiles, bombs and PGMs (precision-guided munitions). The Aeronautical Development Agency is collaborating with the Dehradun based Defense Electronic Application Laboratory on the project has described it as a “self-defending high-speed reconnaissance UAV with weapon firing capability”.

The first flight of the AURA is expected to be carried out in 2016. In the meantime, India has shown interest in the Israeli Harpy and Harop UCAVs, the latter being a “loitering munition” that hovers around till its operator selects a target on the ground. It then launches itself like a suicide bomber and self-destructs on the target for a precise attack.

While all these projects are happening simultaneously, India is also interested in creating a UAV/UCAV that can be flown on solar energy. As it is the nation is dependent on the civilian use of solar energy for solar panels from foreign countries and so the DRDO is looking for partners who can join the military project.

Among other projects in the pipeline is Pawan developed by ADE and the Israel Aircraft Industries. The 120-kilogram Pawan will have day-and-night surveillance capability, an endurance of five hours and a range of 150 kilometers. ADE plans to build four Pawan prototypes under this development program, with Israel Aircraft Industries. The engine will be purchased from abroad.

Among the operational systems is the homebuilt Netra which is a four rotor ultra light surveillance UAV. It is man-portable and is being used by the armed forces in the difficult terrain of the Himalayas.