HAL Wins the Licence to Build Tejas Servo Valves at Home, Closing a Quiet Import Gap

A small valve, an outsized dependency

On 27 June 2026, Hindustan Aeronautics Limited (HAL) and the Defence Research and Development Organisation's Research Centre Imarat (RCI), Hyderabad, signed a Licence Agreement for Transfer of Technology (ToT) that clears HAL to manufacture indigenous Electro Hydraulic Servo Valves (EHSVs) for the Light Combat Aircraft (LCA) Tejas. It is the kind of agreement that rarely makes headlines, yet it plugs one of the more stubborn gaps in India's home-grown fighter programme: a critical piece of flight-control hardware that has historically depended on foreign suppliers.

Servo valves sit at the seam between a fighter's electronics and its muscles. They are precision-machined, tightly toleranced components, and only a handful of firms worldwide build them to aerospace grade. That scarcity has long made them an import bottleneck — and a strategic vulnerability — for any nation trying to build combat aircraft on its own terms.

What an electro-hydraulic servo valve actually does

An EHSV converts a small electrical command from the flight-control computer into a precisely metered flow of high-pressure hydraulic fluid, which in turn drives an actuator that moves a control surface. On the Tejas, these valves help govern secondary flight surfaces such as the airbrakes and leading-edge slats — the surfaces that shape how the aircraft slows, manoeuvres and maintains lift across its flight envelope.

Because the response has to be fast, repeatable and fail-safe, the valves demand exacting metallurgy, cleanliness and calibration. A valve that drifts even slightly out of tolerance can degrade handling or safety margins, which is why so few countries have mastered their production.

Why the transfer matters

The agreement is squarely aligned with the Atmanirbhar Bharat push for self-reliance in defence. By moving EHSV production onto Indian soil, the programme reduces its exposure to overseas supply chains — a dependency that can translate into long lead times, higher costs and logistical friction, especially for a fighter India intends to build and sustain in large numbers over decades.

RCI, a DRDO laboratory in Hyderabad focused on missile and avionics systems, developed the valve technology; HAL will now industrialise it. That division of labour follows a familiar and increasingly productive pattern in the Tejas ecosystem, in which DRDO laboratories hand indigenous flight-control hardware — actuators, control modules and now servo valves — to HAL for series manufacture.

Beyond cost and resilience, indigenisation gives India control over the design, upgrade path and spares pipeline for a component it will need for the life of the fleet — rather than negotiating each of those from a foreign vendor.

From lab bench to production line

Transfer-of-technology agreements are the connective tissue of India's defence-manufacturing strategy: a government lab proves out a technology, then licenses it to a production agency that can make it at scale and to consistent quality. The servo-valve ToT is another instance of that model maturing, converting a laboratory capability into a manufacturable product line inside HAL.

The real test now shifts to the shop floor — qualifying the indigenous valves, integrating them into Tejas production and demonstrating that they match the reliability of the imported units they are meant to replace.

What comes next

The significance runs beyond the current Tejas Mk-1A. The expertise built around electro-hydraulic servo valves is directly relevant to India's next combat-aircraft programmes, including the more capable Tejas Mk-2 and the fifth-generation Advanced Medium Combat Aircraft (AMCA). Each of those platforms will need precisely this class of flight-control hardware — and each is a reason to have the capability inside the country rather than sourced from abroad.

For a programme long dogged by import dependencies, a licence to build its own servo valves is a small, concrete step toward a fully sovereign fighter.

Sources

• Indian Defence News — "Indigenous Electro Hydraulic Servo Valves To Power TEJAS Mk-1A Under DRDO-HAL Pact": https://www.indiandefensenews.in/2026/06/indigenous-electro-hydraulic-servo.html
• Indian Defence Research Wing (IDRW) — "DRDO Hands Over Indigenous Flight Control Systems for LCA Tejas Mk1A to HAL": https://idrw.org/drdo-hands-over-indigenous-flight-control-systems-for-lca-tejas-mk1a-to-hal/