India is seeking two additional Indian industry partners to support the mass production of an indigenous expendable turbojet engine, marking a shift from technology demonstration to the creation of a broader production ecosystem.
The initiative is being pursued by the Defence Research and Development Organisation’s Gas Turbine Research Establishment, or GTRE, which is based in Bangalore and is India’s principal organisation for military gas-turbine research.
The search for additional partners follows the successful development of India’s first indigenous expendable turbojet engine in the 350-kilogram thrust class.
The engine was designed by GTRE and manufactured and assembled by Hyderabad-based Azad Engineering, which was selected as the initial industry partner.
Azad Engineering completed and delivered the first engine to GTRE on 22 July 2026. The delivery represented an important transition from laboratory development to industrial realisation.
The latest move indicates that GTRE does not intend to rely on a single private-sector company for future production. Instead, it is seeking to distribute manufacturing responsibilities among multiple Indian companies capable of producing the engine in significant numbers. This approach is expected to improve production capacity, create industrial redundancy and reduce the risks associated with depending on one supplier for a critical propulsion system.
An expendable turbojet engine is designed for a single mission or a limited number of operating hours. Unlike the engines used in fighter aircraft and transport planes, it is not required to function reliably for thousands of flight hours or to undergo repeated maintenance and overhaul cycles. The engine is instead optimised for simplicity, compactness, reliability, affordability and ease of manufacture. Once installed in a missile, unmanned aircraft or loitering munition, the engine powers the platform during its mission and is not recovered for reuse.
This makes expendable propulsion particularly suitable for weapons and unmanned platforms where the cost of the engine must remain proportionate to the cost of the overall system. The engine developed by GTRE belongs to the 350-kilogram thrust class. Its design is based on a single-spool turbojet configuration comprising a four-stage axial-flow compressor, an annular combustor, a single-stage uncooled axial-flow turbine and a fixed-exit nozzle.
The architecture is considerably simpler than that of a modern fighter engine. It does not require the sophisticated high-temperature materials, cooling arrangements, afterburner systems, variable-area nozzles or long-life maintenance features associated with combat aircraft propulsion.
The absence of turbine cooling helps reduce design and manufacturing complexity. It also makes the engine suitable for expendable applications, in which the turbine is required to operate reliably for a short mission rather than remain serviceable for years.
The propulsion system is expected to support a range of military platforms, including cruise missiles, anti-ship missiles, jet-powered loitering munitions, target drones and unmanned aerial vehicles.
It could also be adapted for other air-breathing weapons and autonomous systems that require a compact jet engine capable of sustaining flight over considerable distances. The engine’s availability could be particularly important for India’s expanding inventory of long-range unmanned platforms and precision-strike weapons.
Many such systems depend on imported propulsion units. Import dependence can create delays, raise procurement costs and expose operational programs to export restrictions, political pressure and supply-chain disruption.
An indigenous engine would give Indian designers greater control over the propulsion system, including its dimensions, mounting arrangements, fuel requirements, control architecture and integration with the host platform.
Domestic production could also allow the engine to be modified for different missions. A missile may require a compact, low-cost engine with a short operating time, while a loitering munition or unmanned aircraft may require better endurance and fuel efficiency.
The move to identify two more industry partners suggests that GTRE is preparing for a structured production model rather than a limited batch of development engines. According to the available production plan, the broader objective is to manufacture approximately 300 engines over a period of five years.
The initial phase is expected to involve the selection of two Indian companies, with each company required to supply three engines over an 18-month period. This first stage would allow GTRE to evaluate the industrial capabilities of the selected companies before issuing a subsequent request for information covering larger production quantities.
The staged model is intended to ensure that companies are assessed not only on their ability to manufacture individual components but also on their capacity to carry out complete engine production, assembly, integration and quality assurance.
The partners will need to demonstrate competence in high-precision aerospace manufacturing.
They are likely to require capabilities in the production of compressor blades, turbine components, combustion-chamber assemblies, shafts, casings, nozzles and other parts that must operate under demanding mechanical and thermal conditions.
The manufacturing process may involve advanced machining, precision grinding, investment casting, fabrication of high-temperature alloys, surface treatment, balancing and non-destructive testing. Engine production also requires strict control over dimensional tolerances. Even small deviations in compressor or turbine components can affect airflow, vibration levels, fuel consumption and overall engine performance.
The selected companies will therefore have to establish robust inspection, traceability and documentation systems. They will also need to maintain aerospace-quality procedures throughout the production chain, including the procurement of materials, component manufacture, sub-assembly, final assembly and acceptance testing.
GTRE’s partnership with Azad Engineering demonstrated the value of combining government research and development with private-sector manufacturing expertise. GTRE retained responsibility for the engine’s design and technological development, while Azad Engineering converted that design into a manufactured and assembled engine.
The company’s role covered end-to-end manufacturing, assembly and integration. This model enabled the DRDO laboratory to focus on propulsion technology while relying on industrial expertise for production execution.
The participation of additional companies could help expand this model across the Indian aerospace sector. It could also encourage companies that have traditionally supplied aerospace components to move into higher-value system manufacturing.
India has a growing network of private firms involved in precision engineering, aerospace components, defence systems, additive manufacturing and advanced materials. However, building a complete gas-turbine engine remains substantially more demanding than producing individual parts. The real test will be whether the new partners can achieve repeatable production quality, maintain delivery schedules and manufacture engines that perform consistently across multiple batches.
The search for additional partners must also be viewed against the background of India’s long-standing difficulties in developing indigenous aircraft engines.
The Kaveri engine program, initiated to power the Light Combat Aircraft, generated valuable expertise but did not achieve the required performance for installation on the aircraft.
The experience nevertheless helped India develop knowledge in compressors, combustion systems, turbines, afterburners, materials and engine testing. The new expendable turbojet is not a replacement for a fighter engine. Its thrust level, operating profile and intended use are entirely different from those of a high-thrust afterburning turbofan required for combat aircraft.
Even so, mastering a smaller and less complex engine can help strengthen the country’s wider propulsion ecosystem. It provides opportunities to improve the domestic supply chain, train engineers and technicians, validate manufacturing processes and develop companies that may later participate in larger propulsion projects. The development also complements India’s efforts to establish industrial partners for more advanced aero-engine programs.
GTRE has separately sought an Indian development-cum-production partner for an Advanced High Thrust Class Aero Engine intended to support future combat-aircraft requirements. That effort involves far more demanding challenges, including the design and manufacture of a high-pressure core, advanced turbine materials, sophisticated cooling systems, digital engine controls and long-duration reliability.
India is also pursuing international cooperation for a high-thrust fighter engine, including discussions with major foreign engine manufacturers.
The expendable turbojet effort therefore occupies a different position within the national propulsion strategy. It offers a nearer-term opportunity to build practical production experience while the country continues to pursue much more challenging combat-aircraft engine objectives.
Another related effort involves the Small Turbo Fan Engine, or STFE, an expendable engine intended for future long-range land-attack cruise missiles. The STFE production plan reportedly envisages around 300 engines over five years, with an initial phase involving two industrial companies supplying three engines each over an 18-month period.
For India, the significance of the initiative lies in this combination of technology, industrial capacity and operational relevance. A small expendable engine may not attract the same attention as a high-thrust fighter turbofan, but it can have an immediate effect on the country’s ability to produce missiles, drones and other autonomous weapons at scale. The decision to seek two more industry partners suggests that GTRE is preparing to make that capability a sustained part of India’s defence-manufacturing base.
Agencies
