Airlines have rejected Mumbai airport operator MIAL’s proposal to temporarily discontinue 265 of 770 weekly international departure slots from Terminal 2, escalating a dispute over how operations should be managed during the redevelopment of Terminal 1.
The standoff puts October 6 at the centre of the dispute, with MIAL asking airlines to identify the international slots they are willing to temporarily give up. Airlines, however, have reportedly told the airport operator that they do not consent to the proposed reduction and are seeking government intervention.
Mumbai International Airport Ltd. (MIAL), operated by Adani Airports, has informed airlines that 265 of the 770 weekly international departure slots at Terminal 2 (T2) will be temporarily discontinued from 23:59 on October 25.
The reduction represents roughly 34% of the current international departure capacity, although it is being described by the airport operator and airlines as a 33% reduction.
The affected slots involve 46 airlines. According to reports, the largest reductions would fall on:
The vacated T2 capacity is intended to accommodate domestic operations that will be displaced when part of Terminal 1 is taken out of service.
The immediate issue is the planned redevelopment of Terminal 1, which primarily handles domestic operations.
MIAL plans to begin the first phase of redevelopment in January 2027, starting with the North Section of Terminal 1B. The section represents roughly one-third of T1's capacity.
Instead of shutting the entire terminal, MIAL plans a phased approach. International capacity at T2 would temporarily be reduced so that some domestic operations can move from T1 into T2.
MIAL has said the move is necessary because Terminal 1 is an ageing facility with long-standing safety concerns. The airport operator also points to a fire incident at T1 in April 2026 as further highlighting the risks associated with continuing operations in the ageing infrastructure.
Airlines have reportedly made clear that they support the refurbishment and redevelopment of Terminal 1.
Their objection is to the way the operational reduction is being imposed.
Carriers argue that supporting T1 redevelopment cannot automatically be interpreted as agreeing to the cancellation or reduction of already approved international services.
They are also questioning whether there was adequate consultation on:
Timing is one of the airlines' strongest objections.
The proposed reductions coincide with the beginning of the winter schedule on October 25. Airlines say their winter schedules had already been approved in June and that aircraft, crews, connecting flights and passenger bookings were planned around that capacity.
They therefore argue that a major reduction in approved capacity should not be introduced unilaterally without a transparent coordination process.
The concern is particularly significant for airlines operating international networks from Mumbai, where removing multiple weekly frequencies can affect aircraft rotations and onward connections far beyond an individual flight.
The two sides also appear to have sharply different views of previous consultations.
MIAL has said that extensive consultations with airlines regarding the future of T1 have been underway since 2020. It says the redevelopment proposal was also presented to the Airports Economic Regulatory Authority (AERA) and subsequently incorporated into the approved tariff framework.
Airlines, however, reportedly dispute whether those consultations amounted to agreement on the latest operational plan.
They have questioned the handling of meetings in July and September and say discussions about redevelopment did not amount to approval for the proposed T2 international slot cuts.
MIAL's latest communication reportedly said a meeting was held on September 16 to facilitate the transition, but that several airlines did not participate or did not submit the requested transition plans. The airport operator subsequently said it would proceed using available operational data and planning assumptions.
Under MIAL's plan, airlines have until October 6 to identify the specific international slots they want temporarily discontinued.
If airlines do not provide the requested information, MIAL has indicated that it will determine the slots itself based on operational requirements.
That provision has become one of the most contentious aspects of the dispute because airlines have reportedly rejected the premise that they should voluntarily select flights for cancellation when they have not agreed to the overall reduction.
On October 3, Adani Airports sought to reassure passengers that the redevelopment would have a limited impact on overall Mumbai airport traffic.
The operator said approximately 91% of Mumbai airport's passenger traffic will remain unaffected, while about 5 million passengers annually, or around 9% of the airport's roughly 55 million passengers, could be temporarily affected by the first phase.
Only the North Section of T1B will initially be demolished, allowing the remainder of Terminal 1 to continue operating.
Adani Airports CEO Arun Bansal said the move to Navi Mumbai would be temporary and would not represent a permanent transfer of Mumbai airport traffic.
The newly operational Navi Mumbai International Airport (NMIA) is central to the redevelopment strategy.
NMIA began commercial operations on December 25, 2025, creating a second major airport for the Mumbai metropolitan region.
Adani Airports is now positioning Navi Mumbai as an alternative for airlines whose operations are affected by the T1 redevelopment.
The airport operator says airlines can temporarily move services to NMIA, while Navi Mumbai is offering incentives to encourage international operations.
These include:
Adani says NMIA has the infrastructure and capacity to accommodate additional traffic during the redevelopment period.
For passengers, however, shifting flights from Mumbai to Navi Mumbai could create its own complications.
Navi Mumbai is geographically separate from the existing Mumbai airport, meaning some passengers could face longer road journeys and potentially higher ground-transport costs.
There is also a difference in User Development Fees (UDF) between the airports. Adani Airports says its proposed passenger vouchers are intended to offset that difference for affected international travellers.
The alternative is for airlines to cancel frequencies altogether or move capacity to other airports, potentially reducing the number of international seats available from Mumbai during the busy winter and festive travel period.
The airport operator argues that the disruption is temporary and that the redevelopment will ultimately increase Mumbai airport's capacity.
Terminal 1 currently handles around 15 million passengers annually. After redevelopment, its capacity is expected to rise to approximately 20 million passengers per year, a 33% increase.
Adani Airports has also said the redeveloped T1 will restore historical airline slots while creating additional capacity for future growth.
Earlier plans for the redevelopment had already envisaged a phased closure of T1 and an increase in capacity, with airlines including IndiGo and Air India involved in discussions about mitigating operational disruption.
The dispute reflects a much larger challenge facing Mumbai's aviation system.
Mumbai's existing airport has long operated under severe capacity constraints, while passenger demand has continued to grow. The opening of Navi Mumbai was intended to create a multi-airport system capable of absorbing future growth.
The redevelopment of T1 is therefore not simply a terminal refurbishment project. It is part of a broader restructuring of how traffic is distributed between Mumbai and Navi Mumbai airports.
Adani Airports describes the two airports as complementary facilities serving the wider Mumbai metropolitan region.
With airlines rejecting the proposed reduction, the dispute is moving beyond a commercial disagreement between carriers and the airport operator.
Airlines are seeking intervention from the Civil Aviation Ministry and want a detailed stakeholder meeting on the redevelopment and transition plan.
Their central argument is that an airport redevelopment should not result in the unilateral cancellation of services that have already been incorporated into the winter schedule.
MIAL, meanwhile, argues that the transition is necessary to safely redevelop ageing infrastructure and that the availability of Navi Mumbai makes it possible to avoid a complete shutdown of Terminal 1.
The next major development is expected around October 6, when the airlines' deadline to identify slots for temporary discontinuation expires.
If carriers maintain their rejection and do not nominate flights, MIAL could proceed with its own allocation of the 265 weekly slots.
That could turn the current disagreement over consultation into a much more consequential dispute over who has the authority to determine which international flights lose capacity at one of India's busiest airports.
| Item | Current plan |
|---|---|
| International weekly departures at T2 | 770 |
| Slots to be temporarily discontinued | 265/week |
| Approximate reduction | 33–34% |
| Airlines affected | 46 |
| Deadline for airlines | October 6, 2026 |
| Proposed start | 23:59, October 25, 2026 |
| T1 redevelopment begins | January 2027 |
| Passengers temporarily affected | ~5 million/year |
| Mumbai airport annual traffic | ~55 million |
| T1 current capacity | 15 million passengers/year |
| T1 future capacity | 20 million passengers/year |
| Future T1 capacity increase | 33% |
