Green Aero’s Sub-kN Jet Engine.
Green Aero jet engine: Bengaluru: In a breakthrough that could reshape India’s small-engine defence ecosystem, Bengaluru-based startup Green Aero has successfully test-fired a sub-kilonewton (sub-kN) jet engine designed to military-grade specifications, marking a major step toward indigenous propulsion solutions for drones and loitering munitions.
The compact engine, developed entirely in-house, represents one of the most significant milestones for India’s private aerospace startups seeking to reduce the country’s reliance on imported propulsion systems for unmanned platforms. According to engineers familiar with the program, the engine demonstrated stable operation across multiple thrust settings and ran continuously for more than 45 minutes during a controlled test conducted at a secure facility near Bengaluru.
A Small Engine With Big Strategic Value
Sub-kilonewton jet engines, which typically produce thrust below 1,000 newtons, are critical components for modern unmanned aerial vehicles (UAVs), loitering munitions, and high-speed target drones. While relatively small in size, these engines enable the high-speed endurance and maneuverability required for modern drone warfare.
Green Aero’s prototype reportedly produced peak thrust exceeding 200 newtons, placing it in the same performance class as engines such as the PBS TJ100, a widely used micro-turbojet manufactured by the Czech company PBS.
Unlike many imported engines that run exclusively on aviation turbine fuel, Green Aero’s design can operate on both jet fuel and diesel. This dual-fuel capability could prove strategically valuable during military deployments, particularly in remote border regions where diesel—shared with ground vehicles—may be easier to supply.
Defence analysts say this feature directly addresses one of the logistical challenges of drone warfare: maintaining consistent fuel supply chains across dispersed operational environments.
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Indigenous Engineering Push
The test aligns with the goals of India’s Aatmanirbhar Bharat program, which encourages domestic manufacturing and innovation across critical defence sectors.
India has historically relied on imported small turbojet engines for UAVs and target drones. By developing the technology domestically, companies like Green Aero aim to close a long-standing gap in India’s propulsion capabilities.
The engine incorporates high-temperature ceramics, advanced alloys, and additive-manufactured components, enabling a high power-to-weight ratio comparable to global counterparts. Engineers also used advanced computational fluid dynamics (CFD) simulations and rapid prototyping methods to accelerate development.
According to sources involved in the project, the entire design cycle—from concept to full test firing—was completed in less than 18 months, an unusually short timeframe in aerospace engineering.
Meeting Military-Grade Standards
The engine was designed to meet standards comparable to those used by major Indian defence organisations such as the Defence Research and Development Organisation and Hindustan Aeronautics Limited.
Military certification involves rigorous evaluation across multiple parameters including:
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Vibration tolerance during high-speed flight
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Thermal cycling under extreme temperatures
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Electromagnetic compatibility with avionics systems
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Long-duration reliability tests
Telemetry from the test run reportedly showed no thermal hotspots, vibration anomalies, or thrust asymmetry, indicators that engineers say demonstrate the design’s maturity.
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Role in Next-Generation Drone Warfare
The Green Aero‘s engine is expected to power loitering munitions, drones that circle above a battlefield before diving onto targets once identified.
India has been actively developing such systems, including the ALS‑50 developed by Solar Industries India. Indigenous micro-turbojets could enable higher-speed versions of these systems and support the development of swarm drone tactics, in which dozens or hundreds of drones coordinate attacks simultaneously.
Such capabilities are increasingly viewed as essential in modern warfare, particularly as conflicts around the world demonstrate the growing role of autonomous and semi-autonomous drone systems.
Bengaluru’s Expanding Aerospace Cluster
Green Aero’s emergence also highlights the growing aerospace startup ecosystem in Bengaluru, long known as India’s technology hub.
The city hosts major research institutions such as the Indian Institute of Science alongside large public sector aerospace firms. This concentration of academic, industrial, and defence expertise has created a talent pipeline for advanced engineering startups.
Industry observers often compare Bengaluru’s aerospace cluster to Hyderabad’s missile and defence manufacturing ecosystem, creating a dual-hub structure for India’s defence innovation landscape.
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Future Applications
Beyond loitering munitions, Green Aero’s propulsion system could support several other defence programs, including high-speed target drones used to test missile systems such as Akash‑NG.
The company is also exploring the development of micro-turbojet variants for training drones and experimental UAV platforms.
Environmental considerations influenced the engine’s design as well. Diesel operation may produce lower emissions during training sorties, making it suitable for repeated testing missions.
Global Interest and Export Potential
With the global drone market expanding rapidly, small jet engines are in growing demand. Analysts believe Green Aero’s technology could attract partnerships with global aerospace firms such as Safran and Honeywell Aerospace, particularly through India’s defence offset programs.
The company is currently preparing for certification flights expected by mid-2026, after which it plans to pursue procurement opportunities with India’s Ministry of Defence under the Innovations for Defence Excellence (iDEX) framework.
Green Aero: Building a Domestic Propulsion Ecosystem
India has long sought to build a full spectrum of indigenous jet engine technologies—from micro-turbojets to fighter aircraft engines. Green Aero’s project complements larger national efforts such as the Kaveri Engine Program developed by the Gas Turbine Research Establishment.
Together, these programs could form a domestic propulsion pipeline covering everything from drones to combat aircraft.
For India’s defence planners, the successful test marks more than just a technological achievement. It signals the growing role of private startups in national security innovation, a shift that could accelerate the country’s push toward self-reliance in critical military technologies.
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