WHY INDIA SHOULD ADDRESS ITS PROPULSION GAP

THE CONTEXT: India’s most ambitious aviation projects — the Light Combat Aircraft Tejas Mk-1A, the twin-engine Tejas Mk-II, the fifth-generation Advanced Medium Combat Aircraft (AMCA) and the Ghatak unmanned combat air vehicle — all hinge on foreign power-plants whose delivery schedules and technology-transfer clauses remain outside New Delhi’s control. The first F404-IN20 engine for 83 Tejas Mk-1A fighters reached Hindustan Aeronautics Limited (HAL) only in April 2025, two years late, with just 11 more promised this calendar year.

THE BACKGROUND:

• • The 1960s HF-24 Marut failed to meet its design potential because Berlin-origin designer Kurt Tank could not obtain a suitable engine; the aircraft was retired by 1990.
  • The DRDO–Gas Turbine Research Establishment’s (GTRE) Kaveri programme (launched 1989) logged >3 000 h of tests but never met thrust or reliability targets.
  • Over 60 % of India’s ­major-arms imports between 2019–23 were propulsion-related components according to the Stockholm International Peace Research Institute (SIPRI).

PROPULSION SOVEREIGNTY: National air-power rests on four pillars: (i) propulsion, (ii) avionics, (iii) weapons, (iv) low-observable structures. Control of propulsion alone multiplies the other three by determining range, payload, climb-rate and growth potential. Propulsion sovereignty is therefore treated in modern strategy literature as a “technological deterrent” akin to nuclear latency.

PROPULSION SCIENCE IN BRIEF:

• • The turbine inlet temperature (TIT) in modern combat engines exceeds 1 700 °C, far above the melting point of nickel-based super-alloys; thus single-crystal blades plus ceramic-matrix thermal-barrier coatings are indispensable.
  • Full Authority Digital Engine Control (FADEC) software governs fuel scheduling and variable geometry; its source code is ordinarily retained by original equipment manufacturers and often classified as a munition.

INDIA’S CURRENT CAPABILITY STACK:

FUNDING & GOVERNANCE REALITY CHECK: The Defence Research and Development Organisation (DRDO) receives only 3.94 % of India’s defence budget (₹26 817 crore in 2025-26) against 15-18 % in the United States and China; within DRDO, aeropropulsion competes for resources with missiles and electronics.

COMPARATIVE GLOBAL APPROACHES

• • United States: Next-Generation Adaptive Propulsion (NGAP) assigns US $3.5 billion each to General Electric and Pratt & Whitney for twin adaptive-cycle prototypes, with milestone-based payments until 2031.
  • United Kingdom-Japan-Italy (GCAP): joint engine core by Rolls-Royce, IHI and Avio leverages pooled intellectual property to de-risk cost for sixth-generation fighter.
  • People’s Republic of China took 20 years to field WS-15 for J-20; shows that even high-investment ecosystems endure multi-decade learning curves.

PRINCIPAL CHALLENGES:

• • Technology denial regimes: Single-crystal casting and FADEC source-code are categorised under International Traffic in Arms Regulations; suppliers retain “black-boxes” in ToT deals.
  • Fragmented demand signal: Separate, small-lot orders for Tejas, AMCA and Navy’s Twin-Engine Deck-Based Fighter prevent economies of scale (>500 engines) essential for amortising R&D.
  • Limited hot-section supplier base: Only two Indian firms possess vacuum induction melting for single-crystal nickel; contrast with >50 vendors in the U.S.
  • Testing lag: Absence of an operational domestic high-altitude test facility forces costly leasing of Russian IL-76 flying testbeds and chambers.
  • Human capital deficit: India fields ~300 aero-thermodynamics specialists versus ~3 000 at GE Aerospace alone; talent drain to civil aviation MRO sector persists.
  • Funding volatility: Year-to-year allocations and delayed cash-flows hamper long-lead procurement of super-alloy ingots and bespoke tooling.
  • Siloed R&D culture: Minimal code and data sharing between GTRE, DMRL, academic labs and private partners; redundancy and re-work inflate timelines.

THE WAY FORWARD:

• • National Propulsion Mission Authority: Establish a statutory authority chaired by the Principal Scientific Adviser with a single-line ₹30 000 crore, 15-year budget to steward all aero-, marine- and armour-engine programmes. Create two competing 110 kN prototypes to avoid single-vendor lock-in. Mandate quarterly public dashboards to enforce time-cost discipline.
  • Propulsion Special Purpose Vehicle (SPV): Form a HAL–Bharat Forge–Safran SPV in Bengaluru with 74 % private equity and a 26 % government “golden share” for veto powers. Peg minimum order of 400 engines across AMCA and TEDBF to guarantee break-even. Grant 10-year income-tax holiday to attract global tier-one vendors.
  • Tier-II Cluster Incentives: Extend Production Linked Incentive (PLI) to turbine blades, combustor liners and powder-metallurgy discs with 12 % incremental-sales subsidy. Anchor clusters in Tamil Nadu and Telangana defence corridors. Leverage state-level capital subsidy to build vacuum-arc remelting and hot-isostatic-press capacity.
  • Unified Certification Board: Merge CEMILAC’s military and DGCA’s civil engine directorates into an Aero-Propulsion Certification Board for one-stop clearances. Adopt European Union Aviation Safety Agency Part-21 standards with military deviations codified. Target 30 % reduction in certification timelines.
  • High-Altitude Test Campus (HATC): Approve GTRE’s ₹1 600 crore proposal for a 40 000-ft altitude-simulator plus sea-level endurance rigs at Peenya. Fund via Viability Gap Financing with a 30-year private-operations concession. Cover 50 % of running cost through civil MRO client rentals.
  • Digital-Twin Design Suite: Procure commercial cloud-based Computational Fluid Dynamics and machine-learning driven probabilistic fatigue tools. Require every new component to undergo 100 % digital-twin validation before prototype casting. Expected to trim 40 % of design-test iterations.
  • Advanced Materials Consortium: Back DMRL-led consortium with MIDHANI, IIT-Madras and CSIR-National Metallurgical Laboratory to indigenise rhenium-rich single-crystal alloys. Allocate ₹800 crore over eight years under the National Superalloys Mission. Publish open-access databases to encourage start-ups.
  • Outcome-Linked R&D Contracts: Shift from cost-plus to Technology Readiness Level (TRL)-gated milestone payments mirroring the U.S. NGAP model. Penalise slip beyond +10 % cost or +6 months schedule through retention money. Provide 5 % performance bonus for early delivery meeting specified thrust-to-weight benchmarks.
  • Human-Capital Acceleration: Institute 200 annual PhD fellowships in turbomachinery under Science and Engineering Research Board, mandating one-year residencies at GTRE. Launch mid-career fellowships for Indian diaspora propulsion experts with five-year sabbaticals. Tie post-doctoral grants to demonstrable hardware deliverables.
  • Export-Control Diplomacy Cell: Create a dedicated cell under Department of Defence Production to negotiate phased ITAR relaxations and CAATSA carve-outs leveraging India’s Quad and Major Defence Partner status. Offer reciprocal market access in civil MRO and helicopter segments. Embed legal specialists to draft watertight intellectual-property carve-ins.
  • Lifecycle Absorption Road-Map: Synchronise induction timelines of AMCA, TEDBF, CATS Warrior drones and future transport aircraft to pull an assured demand of 1 000 engines. Outline a decade-long procurement calendar to reassure vendors. Incorporate upgrade pathways for higher turbine-entry temperatures.
  • Innovation-Linked Grant (i-LINK): Expand iDEX-Prime upper ceiling to ₹50 crore for propulsion sub-systems such as ceramic-matrix liners and additive-manufactured stator stages. Fast-track grants within 90 days via online challenges. Track impact through independent Technology Readiness Level audits.

THE CONCLUSION:

History shows that a fighter’s combat edge is ultimately throttled by the temperature limits of its turbine blades. Unless India treats engine mastery as a national techno-strategic mission — with sustained finance, a unified test-and-certification ecosystem and industry-academic co-innovation — programmes like AMCA risk becoming airframes in search of power-plants, repeating the Marut-Kaveri loop. Strategic self-reliance therefore begins not at the cockpit, but in the crucible of a single-crystal blade.

UPSC PAST YEAR QUESTION:

Q. Foreign Direct Investment in the defence sector is now said to be liberalised. What influence is this expected to have on Indian defence and the economy in the short and long run? 2014

MAINS PRACTICE QUESTION:

Q. Evaluate how India’s propulsion gap constrains its strategic autonomy.

SOURCE:

https://www.thehindu.com/news/national/why-india-should-address-its-propulsion-gap/article69714631.ece#:~:text=Aircraft%20engine%20development%20is%20vital,would%20necessitate%20third%2Dparty%20approvals.