The domain of unmanned aerial vehicles (UAVs) has unsurprisingly emerged as a focus area for indigenous military development and production efforts. Indeed domestic UAV programmes are serving as a draw for the private sector with participation from both medium and small scale enterprises (MSME) as well as large conglomerates. And besides the usual clutch of sub-assemblies, major sub-systems such as sensor payloads and engines are also being increasingly sourced from Indian industry.
The flagship UAV programme at the moment is the Rustom-II being developed in the lead by the Defence Research and Development Organisation's (DRDO's) Aeronautical Development Establishment (ADE) based in Bangalore. The Rustom-II is a medium altitude long endurance (MALE) UAV with an altitude ceiling of 32,000 feet and an endurance of up to 35 hours. This bird is being designed to meet the needs of all three services with different configurations, naturally. However, while the Indian Navy (IN) version is slated to carry mostly electro-optical payloads and maritime patrol radar, the Indian Army (IA) and Indian Air force (IAF) versions are a more involved proposition tailored to carry Electronic Intelligence (ELINT), Communications Intelligence (COMINT) and Synthetic Aperture Radar (SAR) packages as well. In fact a new indigenously developed airborne Ku-band SAR scheduled to commence trials this year on a flying test bed will eventually take pride of place on the Rustom-2.
Two Rustom-2 prototypes have been developed thus far, one of which was displayed at Defexpo 2014 in Pragati Maidan, New Delhi. The programme is currently in iterative development mode with refinements in aerodynamic shaping underway and it is likely that a total of eight prototypes will be built with the last one serving as the base for production variants. While the target weight for the Rustom is roughly around 1800 kilograms (kgs), the current prototypes are about 400 kgs over that benchmark. Moreover it is unlikely that the final variant will be less than 2100 Kgs. With that figure in mind and typical margins for capability growth, DRDO has decided to fit the Rustom-2 with new diesel engines.
As such the two existing 125 HP Rotax 914 engines (one on each wing) are slated to be replaced by new 200 HP class diesel engines supplied by Lycoming. Interestingly, the new engine configuration is slated to be indigenized with a domestically developed equivalent as a result of a collaborative effort between DRDO's Vehicle Research and Development Establishment (VRDE) and Tech Mahindra. The Rustom-2's private sector footprint obviously extends into the MSME sector as well. For instance, Bangalore based FLOTECH Engineering & Trading services is supplying aircraft fuel rigs for the Rustom-2 while Nfotec Digital Engineering Pvt. Ltd from the same city is providing CAD design and CFD analysis support services to the program.
Slated to take to the skies for the first time this year, Rustom-2 prototypes will soon enter a phase wherein critical operational safety aspects such as waypoint navigation back to the nearest friendly airbase in the event of satellite link failure at distances which are also beyond VHF line of sight and the fine tuning of the on board traffic collision avoidance system (TCAS) will be worked upon. After all the operational altitude of the Rustom-2 (i.e 30000 feet) is basically where most civilian airliners fly today. Of course in the near future Indian air traffic control regulations will need to be modified to accommodate the growth of UAV flights in the country. For the moment, the Rustom-2 is confined to military airspace.
The other indigenous UAV bearing legendary Aerospace scientist and engineer, Rustom B. Damania's name, the Rustom-I is also set for interesting times ahead. As revealed by Dr K. Tamilmani, Director-General Aeronautical systems, DRDO, to Geek at Large, Rustom-I is likely to be India's first armed UAV and work is underway to integrate the Helina (which is the air-launched version of the Nag anti-tank missile) with it. Carriage trials are expected to begin this September. The Rustom-2 which will also carry munitions eventually will see weapon release trials in 2017.
Meanwhile, the Central Reserve Police Force (CRPF) has bitten the bullet on the Nishant UAV which is already in service with the IA and some 16 units of a customized version are set to find place in its inventory. Given the terrain in which the CRPF variant will be operated, DRDO labs have worked together to reduce the number of support vehicles for it by a third. Importantly, the CRPF version will fly with an indigenously developed wankel rotary engine with a rating of 55 HP replacing its current ALVIS AR-801 engine.
This engine developed by VRDE is already under production at a private facility operated by SMC in Hyderabad with eight sets scheduled to be delivered soon. The indigenous engine which can apparently be uprated to 65 HP will also power the conventional take-off and landing (CTOL) version of the Nishant which weighs some 25 kgs more than the current truck-launched version and will see its first conventional take-off in April this year.
To understand the large domestic private sector footprint of the Nishant program it could be noted that the GIS solution for it has come from Pegasus software consultants, Digitronics has provided power supply, Meru Precision Industries has supported the development of many sub-assemblies and the Gimballed Payload Assembly and Servo Electronic System has come from Tata Power SED.
The big story of course is the progressive indigenization of the propulsion system for these UAV programs. Propulsion after all is that one thing that stands between the Indian aerospace sector becoming more or less sufficient ( naturally more intense efforts on airborne fire control radars is also required) and being dependent on the West or Russia. I would go out on a limb to say that the pursuit of propulsion technology in general should be elevated to the level of a national ideology in India and effective resources must be made available to this objective. I'll leave you with this video of the Rustom-2 undergoing engine ground runs and taxi trials at its home facility.
