Significant progress has been made in the development of the Advanced Turbo Gas Generator (ATGG) engine by the Defence Research and Development Organisation (DRDO), which represents a crucial development in India’s domestic propulsion technology capabilities.
By strategically combining design quality, manufacturing innovation, and industry engagement, the project puts India in a position to boost its defence manufacturing ecosystem and lessen its reliance on foreign propulsion systems.
Azad Engineering Limited was chosen by DRDO’s Gas Turbine Research Establishment (GTRE) as its only industry partner for the production and complete assembly of the Advanced Turbo Gas Generator engine. Azad Engineering will be responsible for the full end-to-end manufacturing, assembly, and integration of fully constructed engines for defence applications under this cooperation, which was signed in May 2024.
By extending its manufacturing portfolio beyond the power generation and aviation sectors into integrated propulsion system production, the Hyderabad-based precision engineering firm serves as a vital link between DRDO’s design capabilities and production scalability. The
With Azad Engineering expected to start delivering the first batch of fully integrated engines by early 2026, the contract structure places a strong focus on long-term cooperation. This timeline shows that the development phase has advanced past conceptual stages towards operational deployment by reflecting both the design’s technical maturity and the manufacturing partner’s production readiness. The
The ATGG uses a single-spool turbojet arrangement, which prioritises operational reliability, manufacturing simplicity, and compactness. Each of the engine’s four unique functional divisions is tuned for a certain set of performance goals.
The production of the Proof of Concept (PoC) engine using additive manufacturing techniques is a noteworthy technological accomplishment within the ATGG research program. By permitting quick iteration cycles and unique component shapes that are not attainable with traditional machining, this method deviates from normal subtractive manufacturing paradigms. The
The DRDO ecosystem’s additive manufacturing strategy makes use of laser-based Directed Energy Deposition (DED) technology. An indigenously created Large Area Additive Manufacturing (LAAM) system based on powder-based Directed Energy Deposition technology was created by the DRDO-Industry-Academia Centre of Excellence (DIA-CoE) at IIT Hyderabad.
This system, which has a build volume of one meter by one meter by three meters, is one of the biggest metal additive manufacturing machines in India and shows that DRDO can use additive techniques to create huge aerospace components. The
Using laser and blown-powder based DED technology, the LAAM system uses two laser-powder delivery heads for improved heat control and faster deposition rates.
In order to assist the construction of the ATGG PoC engine and validate manufacturing methods prior to scaling to full production quantities, this technology infrastructure makes it possible to produce complicated geometries within engine components. Rapid prototyping, topological optimisation techniques, and the creation of functionally graded materials are all made possible by the additive manufacturing method, which is becoming more and more important for sophisticated propulsion systems. The
The creation of a high-speed permanent magnet alternator (PMA) for electrical power generation is an essential ancillary component included in the ATGG program. In order to function at the high rotational speeds typical of gas turbine engines, DRDO finished developing and testing a prototype high-speed permanent magnet alternator in 2024. The
The permanent magnet alternator is a technically challenging part that necessitates careful consideration of mechanical integrity, thermal management, and electromagnetic design. High-speed alternators that run at tens of thousands of revolutions per minute require precise bearing systems, innovative materials that can endure centrifugal loads, and extensive rotor dynamics analysis.
By doing away with the need for excitation windings and external power supplies, the permanent magnet configuration lowers system complexity while increasing efficiency and dependability—qualities that are especially useful for military applications that require high availability and little maintenance.
Neodymium-Iron-Boron (Nd-Fe-B) and other rare-earth elements provide improved energy density in permanent magnet alternators, allowing for more compact alternators with higher power densities. Using indigenous rare-earth mineral deposits, DRDO’s Defence Metallurgical Research Laboratory (DMRL) has already produced high-energy rare-earth permanent magnet (REPM) components with energy products ranging from 18 to 35 megaoersted (MGOe). The alternator development program is directly supported by this fundamental materials competence, which makes it possible to indigenise crucial magnetic components. The
The alternator’s mechanical durability, electromagnetic performance, and thermal management qualities are validated under representative operating conditions at the 2024 prototype development and testing milestone. The alternator’s preparedness for integration with the entire ATGG engine system is confirmed by the successful completion of this testing step, which also yields crucial information for improving production design.
The Medium-Range Anti-Ship Missile (MRSAM) program has been recognised as the main near-term use of the ATGG, which serves several strategic defence applications. Because of its lightweight design and compact single-spool architecture, the engine is especially well suited for cruise missile propulsion, where weight penalties, thermal signatures, and volumetric restrictions are important design considerations. The
In addition to anti-ship missile uses, the engine architecture is highly versatile for derivative configurations that include trainer aircraft, target drones, unmanned aerial vehicles (UAVs), and auxiliary power units.
By adding more stages or auxiliary systems, the scalable turbojet core allows for the construction of compact turbofan and turboshaft variations that support a wide range of defensive platforms. Because of its adaptability, the program’s strategic worth is increased and research investments can be spread over a variety of weapon systems and platforms. The
DRDO’s faith in Azad Engineering’s precision manufacturing capabilities and scalable production capacity is demonstrated by the company’s selection as the exclusive production agency. End-to-end assembly of integrated turbojet engines is notably supported by the enhanced manufacturing infrastructure at Azad’s Hyderabad facilities, which is a major capability improvement within India’s defence industrial base. The
The program highlights India’s proven ability to design domestic gas turbine engines using state-of-the-art technologies, a competence confirmed by earlier initiatives like the Kaveri engine development initiative. The gathered technological knowledge, materials science skills, and design technique have guided the creation of more targeted, feasible propulsion systems like the ATGG, even though the Kaveri program faced considerable obstacles in reaching production-ready performance standards. The
By building domestic capacity in cutting-edge propulsion technologies, the ATGG development program is a prime example of India’s strategic commitment to “Atmanirbhar Bharat” (self-reliant India).
The program exemplifies an integrated approach to defence technology self-sufficiency by utilising state-of-the-art additive manufacturing techniques and merging DRDO’s design and research capabilities with Azad Engineering’s production competence. The
With the first deliveries anticipated in early 2026, the development timeframe is an ambitious but doable plan that reflects the design’s technological maturity and the industrial partner’s manufacturing readiness.
If this initiative is carried out successfully, India would become a reputable domestic producer and developer of contemporary turbojet engines, which will have a big impact on operational autonomy on various defence systems.
The ATGG architecture’s incorporation of high-speed permanent magnet alternators satisfies a crucial subsystem requirement and demonstrates DRDO’s capacity to create intricate electromechanical components using domestic resources and manufacturing know-how. The 2024 prototype development milestone positions the program for a smooth transition to full-scale production and strengthens confidence in technical execution.
