TAPAS-BH-201 is an unmanned aerial vehicle (UAV) with a long endurance that was formerly known as Rustom-II and is being developed by India along the lines of the American Predator drones.

The Bengaluru-based Aeronautical Development Establishment (ADE) is responsible for the design and development of Unmanned Aerial Vehicles (UAVs) of various designs. In this effort, ADE was tasked with designing and developing the Medium Altitude Long Endurance (MALE) UAV Tapas BH-201, as well as creating an Aeronautical Test Range (ATR) in Chitradurga, Karnataka.

The UAV is being developed to meet Intelligence, Surveillance, and Reconnaissance (ISR) mission needs of the Tri-Services. In addition, the UAV can be utilised for civil purposes, such as rescue and relief missions during natural disasters, etc.

Tapas development is a multi-disciplinary effort including multiple DRDO labs, small/medium-sized vendors, and ADE as the coordinating agency. IAF and IA have positioned a specialised Project Management Team (PMT) within ADE to consistently provide valuable contributions for the design of systems and subsystems.

The EP&IP of the IAF are actively involved in all flight testing and have contributed to the refinement of the Ground Control System and its systems (GCS). To satisfy the interim Joint Staff Qualitative Requirements (JSQR) of the three Services, Tapas was intended to take off and land from a runway with the assistance of an external pilot or automatically using an ATOL system.

At ATR, Chitradurga, six airframes have been constructed and 25 flight trials have been conducted utilising airframes AF 3 to AF 5. Tapas is the nation’s first UAV to receive certification from the Centre for Military Airworthiness (CEMILAC).

During the testing, Tapas attained a maximum endurance of 85 minutes, an altitude of 4500 metres, and a range of 40 kilometres. Flight tests of an imported Electronic Intelligence (ELINT) payload and an indigenously built medium-range electro-optic payload developed by ADE and IRDE, Dehradun, were successful.

Tapas UAV: Performance Capabilities

• Service Ceiling: 32,000 ft, Operating Altitude: up to 30,000 ft 
• Control and carry out mission through Internal Pilot (IP) from Ground Control Station (GCS)
• Endurance (take-off to landing) of 24 hours with Long Range ElectroOptic (LREO) and Synthetic Aperture Radar (SAR) payloads at an altitude of 20,000 feet (about 7 km)
• Capable of carrying multiple payloads like Electro-0ptic, Signal Intelligence, Image Intelligence along with Situational Awareness Payloads like Traffic Collision Avoidance System (TCAS), Identification of Friend or Foe (IFF), Automatic Identification System (AIS) T
• Launch capability from an altitude of 11,000 ft

Tapas UAV: Salient Features

• Multi-mission capabilities with variety of payloads.
• State-of-the-art real-time simulator to train external pilot.
• World class GCS & datalinks.
• Advanced Ground Support Systems (RAIR & HILS).
• Flight Control (GTH & GHH) Logics.
• Airworthiness Certification by CEMILAC (DO178B-Level A); first time in the country for UAV.
• Easy up-gradation and customization based on user requirements.
• Easy maintenance and cost-effective product lifecycle support.
• Technologies being developed, legacy for future UAV/UCAV.

Tapas UAV: Aerodynamics

Tapas has been developed with a big endurance parameter, minimal drag, and a turbocharged IC engine that consumes less gasoline in order to attain more endurance and a greater ceiling. To lessen the resulting drag, a new high lift air foil, ADE-LS-E2, has been designed with high endurance parameters, a high aspect ratio, and the optimal taper ratio.

The current aerodynamic configuration is the result of a multidisciplinary optimization strategy that took into account aerodynamics, structural, flight mechanics, payloads, and other factors. Initial configuration design made considerable use of the Panel Code and RANS solver for CFD study. Prior to the successful flight testing of a UAV, the aerodynamic properties and performance were validated in wind tunnel tests.

Tapas UAV: Airframe

Ab initio airframe design for the Tapas is mostly composed of high-performance composites. The airframe is constructed with sufficient strength and rigidity. In addition, the design includes provisions for a range of payload attachments and ample fuel tank space.

The creation of an aircraft’s airframe is a difficult undertaking requiring structural design and analysis, as well as estimates of the wing’s dynamic and aeroelastic properties and translation of the design into wing production.

Airframe development made efficient use of sophisticated techniques for analysis, modelling, and digital mockup, which led in the rapid realisation of the airframe. It also provides design and process optimization flexibility. Airframe development, testing, structural qualification, and airworthiness certification occurred.

Tapas UAV: Landing Gear

For flight trials, M/s Timetooth’s indigenously developed Landing Gear has been approved by CEMILAC and the Directorate General of Aeronautical Quality Assurance (DGAQA). Combat Vehicles Research and Development Establishment (CVRDE), Avadi, has taken on the task of developing a retractable landing gear for the Tapas.

Tapas UAV: Ground Control Station

The Ground Control Station (GCS) is being used for:

• Displaying the location of UAV and health status of its on-board systems.
• Displaying the search footprint of the payload on the moving map.
• Providing dynamic mission and Payload sensor re-tasking during operational mission execution.
• Receiving, processing, formating, storing and retrieving flight and payload data and for performing exploitation of payload data.
• Providing the operator a caution/ warning when a malfunction of UAV system is detected/identified.
• Providing Imagery exploitation capabilities to meet the mission objectives.
• Providing an online SIGINT/ELINT analysis capability with geo-location facility.
• Recording full SIGINT/ELINT data for offline analysis.
• Supporting simultaneous control of more than one UAV.

The GCS is able to receive data/status and control UAV payloads. The Remote Video Terminal (RVT) allows users of varying levels to access displays and images from on-board payload sensors.

The functional requirements of GCS consist of communication, mission planning, Air vehicle control, payload management, payload video processing and recording, flight data recording, and post flight analysis and playback.

Tapas UAV: Featuers

• Testing of UAV using inbuilt Flight Line Tester (FLT)
• Mission planning and validation
• Monitor and Control of UAV in all the modes of Flight
• Monitor and Control of all the UAV parameters in all the phases of flight
• External Pilot interface
• Payload control and monitoring
• Automatic takeoff and landing system (ATOL) interface
• Health monitoring of UAV systems, GCS, GDT, EP and SATCOM
• Recording of UAV and Payload data
• Synchronization of all the UAV parameters
• Dissemination of UAV sensors data to services in required format
• Replay of recorded information
• Post flight analysis
• Inter and Intra communications

Tapas UAV: Data-Links

• Range: 250km.
• Simultaneous operation of short range LOS, long range LOS.
• Datalink redundancy.
• Programmable data rates.
• Data-link security & Anti-jamming.
• Wide bandwidth—simultaneous downlinking of payload data (ELINT, COMINT, SAR, MPAR).
• Simultaneous viewing, overlaying and cueing of all payload data.
• Simultaneous FLIR, CCD downlink.
• HD Video downlink.
• More than 40 km RVT range.
• Display of all payload data on RVT.

 Tapas UAV: Features

• Anti-Jam/clear command up-link
• Integrated payload & telemetry down-link
• Real time, full motion EO & IR digital compressed video
• Multiplexed user data for SAR/MPR/ESM
• Full duplex voice link for ATC
• User selectable COMSEC (uplink & downlink)
• Steerable on board directional antenna
• Monopulse ground tracking antenna (azimuth)
• Shipborne Terminals for maritime surveillance
• LOS & SATCOM operation

Tapas UAV: Real-time Simulation

Real-time Simulator is a facility for external and internal pilot training. Emergency test scenarios can also be simulated for pilot training purposes.

Tapas UAV: Higher Power Engine (HPE)

The indigenous creation of a more powerful engine has reached an advanced level, with one engine having been sent to ADE for ground testing after 50 hours of endurance testing. VRDE, Ahmednagar, is coordinating M/s Jayem Automotive, Coimbatore’s development of an indigenous power plant.

Tapas UAV: Flight Control System

The Flight Control System (FCS) includes flight control sensors, a flight control computer, control law, and actuators. INS, Air Data sensor, heading sensor, Vertical gyro, GPS receiver (SBAS), Rate gyro, etc. are flight control sensors.

The sensor suite is chosen to provide redundancy for navigation and control law computation as a duplex system. The TAPAS UAV system is Fail Safe.

Onboard Flight Control Computer conceived by ADE and developed by L&T, certified DO-178B Level A. ADE has also developed the Flight Program (OFP) to meet flight criteria. Control Law Design (CLAW) has undergone numerous iterations after considering flight configuration needs.

ADE designed the Linear Actuators for Control Surface and Flap, which are now being developed by ECIL, Hyderabad. The Software produced with ADE adheres to the Mil- 2167A standard.

For this programme, the Research Centre Imarat (RCI) in Hyderabad is responsible for the design and development of G3INS and Rotary Actuator. A Hardware-in-the-Loop Simulation (HILS) integration test facility for testing and clearance of FCS and FCS-related systems has been established.

Tapas UAV: Payload Indigenization

The development of indigenous payloads has reached a mature stage. The development of a SAR payload has reached an advanced level, with a prototype currently conducting flight trials and evaluation aboard a Dornier aircraft. The development of ELINT has been finished, and the aircraft EMBRAER is currently conducting flight trials.

The payload for COMINT is also in an advanced level. The Instrument Research and Development Establishment (IRDE) in Dehradun is in charge of developing EO payloads. The MREO development has reached an advanced stage, with a prototype installed in Tapas (AF 5) and tested in flight. Existing software is now being upgraded. Three sets of payloads have been imported to fulfil the immediate needs of the programme.

Tapas UAV: Production

A consortium comprised of HAL and BEL is participating in the development of Tapas from the stage of design. The teams are actively participating and ToT is occurring concurrently.

After receiving the subsystems, the consortium will serve as the production’s lead integrator. The programme is improving the range, altitude, and endurance of the flight trials in the second half of this year, at which time all imported and domestic payloads will be flight-tested.