Kolkata’s Netaji Subhas Chandra Bose International Airport has lived for years as the natural eastern gateway to India’s skies. But functionally one of the country’s most constrained major hubs. The terminal bottlenecks in monsoon have kept its capacity capped around 26 million passengers a year even as traffic to the Northeast, Bangladesh and Southeast Asia has risen. That makes the current secondary‑runway reconstruction and terminal expansion more than just another infrastructure project but a necessity.
Technically, Kolkata already has two runways. Years of use and heavy monsoon rain left it with rigid sections and craters and it's a common knowledge that it had 'lost flexibility at multiple places'.
That is what the current project is designed to change. The Airports Authority of India has launched a Rs.223.6 crore overhaul of the secondary runway and key taxiways. In parallel, AAI has started Phase III reconstruction of a critical section of the secondary runway, extending and upgrading it to meet Runway End Safety Area norms and better share load when the main runway is out of service.
Kolkata is trying to ensure that its secondary strip can reliably handle traffic whenever the main runway is down, and take more of the load in peak waves. A smooth, structurally sound secondary runway and stronger taxiway network let ATC use more flexible arrival‑departure patterns, reduce holding, and maintain operations in bad weather or during maintenance closures.
The current integrated terminal (T2) was designed for about 26 million passengers per annum by 2024–25, peak‑hour crowding and swing‑gate congestion were already forcing stopgap fixes. A modular project has now added roughly 71,000 sq ft of extra floor space by expanding departure and arrival levels, and reconfiguring domestic and swing‑gate seating areas.
Officials say these upgrades will lift capacity from 26 to 28 million passengers per year. Once finished, that building is expected to add capacity for 11 million international passengers annually.
The long‑term plan, as outlined in expansion proposals sent to the Centre, is to convert the existing integrated terminal completely to domestic use with a capacity of about 34 million domestic passengers per year while the new international terminal handles roughly 11 million international.
Kolkata’s geography makes it far more than a metro gateway. It assimilates three critical aviation corridors: Northeast India-NSCBI is the main trunk gateway feeding Guwahati, Agartala, Imphal, Silchar, Dibrugarh and other Northeastern airports, especially for passengers from the rest of India who prefer Kolkata over Delhi for shorter sectors and lower fares. Bangladesh-Dhaka and Chittagong are closer to Kolkata than to most other major Indian centers, and multiple Indian and Bangladeshi carriers have historically used Kolkata as a stepping stone for trade, labour and medical travel across the border. Myanmar and the Bay of Bengal for routes to Yangon, Mandalay and onward to Thailand or Malaysia, Kolkata is the natural Indian starting point, particularly for eastern and Northeastern states.
Despite that, NSCBI has often been treated as a “forgotten hub” in national aviation planning. Policy and investment attention went first to Delhi, Mumbai, Bengaluru and Hyderabad; Kolkata’s big modernisation push in the late 2000s and early 2010s expanded capacity to 24–26 million, but since then, infrastructure has lagged demand.
The current expansion changes that calculus. A more robust secondary runway and expanded terminal give Kolkata the ability to absorb more Northeastern flows, more Bangladesh traffic and more regional international links without melting down in the evening peak. That makes it an attractive proposition for airlines looking to build hub‑and‑spoke patterns centered on eastern India.