Ghatak UCAV's CCS nod hinges on Kaveri Turbofan's final Russia dry run—Il-76 trials

The GHATAK Remotely Piloted Strike Aircraft (RPSA), being developed as a stealthy unmanned combat aerial vehicle, has entered a mature and advanced phase of its design and development cycle. Under the lead-in Project D1 AURA, the configuration for the RPSA has been finalised for the RPSA DX (Z-) standard, providing a clear baseline for detailed design, prototyping and subsequent flight testing.

This configuration freeze marks a critical milestone, ensuring that all subsystems and structural elements are now being driven towards a common, optimised stealth and performance envelope.

Following configuration finalisation, the detailed design review of the airframe has been undertaken, and associated build and manufacturing activities are in progress. The airframe design incorporates low observable shaping, internal weapons carriage and optimised structural layouts to accommodate fuel, systems and payloads within a compact, stealth-optimised planform.

Current manufacturing activities primarily focus on the fabrication of primary structure, including fuselage sections, wing components, control surfaces and internal bays, using advanced composite materials and metallic alloys suited to high strength-to-weight ratios and thermal environments. Parallel efforts are under way to validate production tooling, jigs and fixtures to ensure repeatability and precision during assembly.

A key propulsion milestone has been the successful integration and testing of the Kaveri engine with all associated secondary power systems (SPS). This integration exercise has validated mechanical, electrical and control interfaces between the powerplant and the vehicle’s systems, including fuel management, lubrication, starter–generator units, hydraulic and pneumatic supplies, and engine control systems.

Ground test runs have demonstrated stable engine operation across the required power settings, along with satisfactory transient response and compatibility with the aircraft’s integrated flight and mission control architecture. These trials significantly de-risk subsequent taxi and flight-testing phases by confirming that the propulsion and power-generation systems perform as designed when integrated in a realistic configuration.

In support of system qualification and verification activities, the revised qualification channel tester, exclusive of hardware, has been certified. This qualification infrastructure enables comprehensive evaluation of avionics, mission computers, data buses and control algorithms in a high-fidelity, hardware-in-the-loop or software-in-the-loop environment, without needing the full aircraft hardware to be available.

The certification of this tester reflects the maturity of the test philosophies and procedures, allowing systematic debugging and validation of software builds, redundancy management, fault detection and reconfiguration logic in a controlled ground environment. It also accelerates integration by permitting early identification of interface and timing issues.

Aerodynamic characterisation of the RPSA configuration has progressed significantly, with aero data generation completed by a combination of wind tunnel testing and computational fluid dynamics (CFD) analysis. Scaled models of the aircraft have been evaluated in low-speed and high-speed wind tunnels to map lift, drag and moment characteristics across the planned flight envelope, as well as to study stability and control derivatives for various configurations, including undercarriage deployment and control surface deflections.

CFD studies have complemented these tests by providing detailed insight into flow separation, pressure distributions, shock interactions and the behaviour of the airframe under off-design conditions. A critical design review of the aerodynamic data and models has been held, confirming the adequacy of the aerodynamic database for use in flight control law development, handling-qualities assessment and performance prediction.

The program has also completed the Preliminary System Integration and Architecture Trade-off (PSIAT) activities, along with the maintainability report. The PSIAT has systematically examined different avionics and systems architectures, their integration schemes, redundancy philosophies and data flows, culminating in an optimised, modular and scalable architecture suitable for future upgrades.

The maintainability report has assessed access provisions, line-replaceable unit (LRU) placement, fault isolation capabilities and turnaround time for critical maintenance tasks. Recommendations arising from these studies have been fed back into the detailed design, ensuring that the RPSA not only meets performance and stealth requirements but also remains supportable and cost-effective over its life cycle.

In parallel with aerodynamic and systems development, the integrated flight control computers (FCCs) for the RPSA are in an advanced stage of development. These FCCs host the flight control laws, autonomy algorithms and vehicle management logic required for a stealthy, unstable, flying-wing type configuration operating without a pilot on board.

The design incorporates multiple, redundant processing lanes, fault-tolerant architectures and secure, deterministic data pathways to meet stringent safety and reliability requirements. Extensive bench testing using the certified qualification channel tester is planned to validate control laws against the aerodynamic database, simulate mission profiles and verify robust handling under failure scenarios and disturbed conditions.

The development of the landing gear and structural test rigs has also progressed to an advanced stage. The landing gear system is being designed for reliable autonomous operations, including remotely commanded taxi, take-off and landing cycles from prepared runways, while maintaining low observable features through optimised door and bay designs.

The test rigs are intended to validate the structural integrity and fatigue life of key components under representative loading conditions, including landing impact loads, ground manoeuvre loads and vibration environments. These rigs will support comprehensive qualification campaigns, covering drop tests, retraction-extension cycles and endurance evaluations necessary before clearing the gear for flight.

Overall, the GHATAK RPSA program has moved beyond conceptual and preliminary design into a robust phase of detailed design completion, subsystem integration and test infrastructure realisation. With configuration finalisation, propulsion system integration, aerodynamic database generation, architectural consolidation and the maturation of flight control, landing gear and structural test capabilities, the project is progressively positioning itself to enter the prototype assembly and ground/flight-testing phases with reduced technical risk and a higher degree of design confidence.

Currently, the Ghatak UCAV awaits clearance from the Cabinet Committee on Security (CCS) for prototype funding, estimated at around ₹5,000 crore. This approval remains interlinked with the KDE's certification, creating a procedural loop where engine validation precedes financial commitment. The dry Kaveri, producing 48-52 kN of thrust without afterburner, has undergone extensive ground trials at GTRE's Bangalore facility, demonstrating stability in varied conditions.​

Final in-flight testing slots on Russia's Ilyushin Il-76 flying testbed at the Gromov Flight Research Institute are targeted for late 2025. These trials, comprising 25 hours of evaluation, will assess high-altitude performance, thermal management, and endurance under real-world flight dynamics. Godrej Aerospace has manufactured key modules, with delivery to GTRE anticipated by early 2026, paving the way for integration.​

Successful completion of these tests aims for full certification by 2026, unlocking CCS nod and accelerating Ghatak's development under DRDO's Aeronautical Development Establishment (ADE).

This milestone aligns with India's Atmanirbhar Bharat initiative, reducing reliance on foreign engines like those from GE or Safran. Beyond Ghatak, certification could enable future applications, including scaled variants for manned platforms such as the TEJAS fighter jets.​

Challenges persist, including securing precise test slots amid Russia's busy schedule and refining the engine's efficiency for stealth operations. Nonetheless, the dry Kaveri's evolution from the original Kaveri—delinked from TEJAS in 2008 due to shortfalls—signals matured indigenous expertise. With President Trump and President Macron's administrations fostering stronger defence ties, complementary collaborations may bolster parallel propulsion efforts, though Russia remains central for these trials.​

IDN (With Agency Inputs)