India's domestic aviation market is now the world's third largest. Airlines have ordered more than 1,500 aircraft. The number of airports has more than doubled since 2014, from 74 to 159. By the usual scorecard, this is a remarkable success.
Look closer at what those assets actually do, and the story becomes more nuanced. Of the 669 routes launched under UDAN, the flagship scheme to connect smaller cities by air, only about half are still flying. An audit by the Comptroller and Auditor General found that once the subsidy supporting a route ends, about one in ten routes continues on its own.
The easy explanation is that India's regional aviation market simply is not ready. But almost everything else moving between tier-2 and tier-3 cities is booming. Trains run close to capacity. Highways carry more traffic than planners expected. Business travel by road and rail continues to rise.
The challenge, then, is not simply demand. It is that an airport is only one layer of the aviation stack, and the next phase of growth depends on getting two other layers right: what a route is designed around, and what kind of aircraft flies it.
The government's recently revamped UDAN policy, often referred to as UDAN 2.0, acknowledges some of this by placing greater emphasis on airport viability, economic potential and industry participation. The next leap in regional aviation will come from designing an integrated network around economically vibrant corridors, hub connectivity and the aircraft best suited to serve them.
UDAN's original unit was the route: start a flight and keep it airborne for a certain period of time. But viability depends on whether that flight plugs into a wider network of onward connections.
The smarter unit is the corridor: the business, tourism, healthcare and trade traffic already moving between two economic centres by road and rail. Even a strong corridor can fail if the route was never designed to connect beyond its destination.
Another challenge is the aircraft flying on a corridor. India's regional fleet is effectively limited to two options, and neither fits many of the regional routes it is expected to serve.
At the smaller end, ATR turboprops carry up to 70 passengers. They are efficient on short hops but too slow to operate more than a couple of trips a day on regional corridors. At the larger end, airlines fly A320s and 737s seating 150 to 190 people, superbly efficient, but only when a route is busy enough to fill that many seats several times a day. Even when IndiGo expanded into regional connectivity, it turned to ATRs, leaving the gap in the middle largely unaddressed.
What India needs is the aircraft in between: the 70-to-120-seat category represented by the likes of Embraer's E-Jets and rivals such as the Airbus A220. These aircraft exist precisely for corridors too thin to fill a 180-seat plane several times a day, but too important to be served only by a slow turboprop.Consider corridors like Coimbatore to Pune, Indore to Nagpur, or Lucknow to Bhubaneswar. These have real, growing demand that still cannot sustain a mainline jet at high frequencies.
The logic is simple: a 90-seat jet flying a route four times a day serves passengers better than a 180-seat jet flying it once. The total number of seats is the same, but the odds that a business traveller finds a flight that fits their schedule improve dramatically. On a mid-density corridor, what people value most is frequency, not size.
Brazil built much of its domestic network around this. Embraer is a Brazilian company that grew up solving this problem for a country whose economy, like India's, is spread across dozens of mid-sized cities rather than concentrated in three or four. The United States similarly relies on regional jets to serve markets too large for turboprops and too small for mainline aircraft.
IndiGo built its dominance by primarily operating A320s, one aircraft family. It helped them with simpler maintenance, simpler training, tighter scheduling and quicker turnarounds.
As India's economy spreads across dozens of mid-sized clusters, the mainline model alone cannot unlock it. The middle tier needs its own aircraft, its own economics and its own reason to exist, designed for the corridors the trunk fleet was never meant to serve.
With metro cities like Delhi and Mumbai now having two airports, India can start treating hub access as a currency of regional aviation, rather than the flight itself. A regional aircraft with nowhere to connect at the other end is simply an expensive way to visit a runway, the real asset is the slot that lets it become part of a larger network. As dual-airport cities such as Noida and Navi Mumbai take shape, there is an opportunity to design some access around connectivity as well.
We also need to see the whole picture before deciding where to fly. FASTag records, railway data, airport traffic and GST filings each contain part of the answer to which corridors are quietly becoming stronger. Put them together, and routes become less about prediction and more about reading signals already emerging in the economy. It also suggests a different way of measuring success: not by counting routes or airports, but by measuring what travellers actually experience, the reduction in friction between places that increasingly want to be connected.
There is a bigger prize in getting this right. India's aviation ambitions, including assembly, maintenance, leasing and systems integration, are often discussed as industrial goals. They are better understood as the natural outcome of a stronger domestic regional aviation network.
The evolution of UDAN reflects this growing recognition. The next step is to evolve from expanding connectivity to engineering network effects. Much of the infrastructure is now in place. The next phase is to build the network effects that allow those assets to realise their potential and help millions fulfil their hawai chappal to hawai jahaj dreams.
