Mumbai International Airport Ltd (MIAL), operated by Adani Airports, has reiterated that capacity equivalent to five million passengers per annum (MPPA) must be restricted at Mumbai airport from the Summer 2027 schedule, even as airlines maintain they have not agreed to shift international operations to Navi Mumbai International Airport (NMIA).

In an email to Airline Operators Committee (AOC) members sent on October 19, MIAL said individual airlines could choose to relocate some or all operations to NMIA, temporarily suspend flights at Mumbai airport until Terminal 1 is redeveloped, or explore other alternatives. It also said historic slots at Mumbai airport would be restored once the terminal is operational again, which it expects by 2030.

The correspondence highlights the key disagreement between the airport operator and airlines: MIAL says the October 13 meeting established a collaborative process to explore alternatives, while the AOC maintains that airlines have not consented to the proposed capacity reduction.

The airport had also sent a reminder email on October 17 stating that airlines need to participate in planning sessions and no airline was missed. “The purpose of these consultations is to avoid any perception of unilateral decision-making. We want to provide a genuine, collaborative platform to discuss all possible scenarios mutually. We look forward to a transparent and productive discussion at our upcoming meeting on 28 October 2026 to achieve mutually acceptable solutions,” the email read.

But the flexibility offered to airlines does not resolve the central disagreement: whether MIAL has established the need for the proposed capacity restriction and whether the transition can proceed without airlines' consent.

The Airline Operators Committee (AOC), which represents airlines operating from Mumbai, has maintained that carriers have not agreed to the proposed reallocation and that participation in individual consultations cannot be treated as acceptance.

“The rejection is very clear from the beginning. They are reducing slots for international airlines, which must be discussed before they do so. There is a process to follow,” an AOC spokesperson told The Core.

The spokesperson said the issue was linked to compliance with the Ministry of Civil Aviation's slot-allocation guidelines and the need for consultation before changes to international operations were made.

The Ministry of Civil Aviation’s May 2013 slot-allocation guidelines lay down the framework for allocating flight slots at congested airports, including the principles of transparency, non-discrimination and historic precedence for airlines that have used their slots in accordance with the applicable rules. Slot changes must follow the prescribed allocation and coordination procedures.

The AOC has argued that MIAL’s proposed reduction in international operations must comply with these guidelines and be preceded by meaningful consultation with affected airlines.

The Five-Million-Passenger Question

MIAL's position is that capacity equivalent to five MPPA must be restricted to facilitate the redevelopment of T1. Airlines, however, want the airport operator to establish how that figure has been calculated and whether the disruption can be managed through existing and planned capacity at Mumbai airport.

“There has to be a consultative discussion about Terminal 1. There has to be a discussion on capacity. Without that, how can they just arbitrarily decide that they have to cut five million?” the AOC spokesperson said.

The committee has questioned the proposed reduction in international operations at Terminal 2 (T2), citing T1's current passenger throughput of below 10 MPPA and the expected addition of approximately five MPPA of capacity at T2 by March 2027.

Airlines have sought the detailed T1 refurbishment plan, including its scope, structural safety assessment, implementation phases, timelines and arrangements to accommodate traffic during construction. They have also asked for terminal-wise capacity and utilisation data and an assessment of alternatives to the proposed traffic reallocation.

The distinction between a terminal's designed capacity and the number of passengers it currently handles is important to the dispute. Airlines want to know how much capacity will actually become unavailable during redevelopment, how traffic can be accommodated across the airport and whether the proposed restriction is proportionate to the capacity being taken out of service.

Without those details, the AOC has argued, airlines cannot properly assess the operational implications of the proposed transition.

MIAL Says Airlines Must Start Consultations

MIAL, meanwhile, says the next step is for individual airlines to engage with their network operators and assess their options ahead of the October 28 stakeholder meeting.

“The initial conversation was that we had proposed it, and then they said they were not ready at the moment. They asked for time till the summer,” a MIAL spokesperson told The Core.

The spokesperson said airlines were expected to discuss the proposal with their network operators before the next meeting, adding that the summer schedule would need to be finalised in November.

“Which is why the reminder email has gone, saying that you should at least start meetings with your network operators,” the spokesperson said.

MIAL has maintained that the process is continuing and that the proposed transition needs to be worked out with individual airlines. Its latest communication gives carriers the option of shifting some or all operations to NMIA, temporarily suspending operations at Mumbai airport until T1 is operational again, or exploring other arrangements.

The airport operator has also reiterated that historic slots will be restored once T1 is redeveloped. However, airlines say this assurance does not address their immediate concerns over the need for the capacity restriction, the timing of the proposed changes and the operational consequences of moving international traffic.

How The Dispute Began

The disagreement intensified in early October after MIAL proposed reallocating international traffic from T2 to NMIA to accommodate passengers affected by the redevelopment of T1.

In an email dated October 16, MIAL asked airlines to engage with its network planning and commercial teams to finalise the proposed reallocation of five MPPA of international traffic for the Summer 2027 schedule.

The AOC pushed back, saying airlines had not committed to any transition plan. It also maintained that participation in individual discussions should not be interpreted as acceptance of the proposed reallocation.

The latest exchange follows an October 13 meeting between MIAL leadership and airline representatives. Adani Airports' senior leadership, including Jeet Adani, had assured airlines that the transition linked to the T1 redevelopment would be handled through a collaborative and consultative process.

However, the meeting did not produce an agreement on the proposed traffic reallocation.

The Ministry of Civil Aviation also intervened in early October, asking MIAL to defer the proposed transition and consult airlines on a mutually agreed arrangement.

The Slot-Allocation Dispute

The AOC has asked MIAL to confirm that no unilateral action affecting traffic allocation or airline slots will be taken until meaningful consultations have taken place and the applicable slot-allocation guidelines have been followed.

The committee and its member airlines have categorically rejected unilateral traffic reallocation, slot reductions or cancellations, and relocation of international operations without due process. They have cited the Ministry of Civil Aviation's May 2013 slot-allocation guidelines and the International Air Transport Association's Worldwide Airport Slot Guidelines.

For airlines, the issue is not simply whether flights should move to NMIA. Changes to international operations can affect aircraft deployment, crew planning, passenger bookings and connections across an airline's network. Carriers therefore want the capacity requirement, construction schedule and transition arrangements to be established before they make operational commitments.

MIAL, on the other hand, maintains that the capacity restriction is necessary and that airlines must now engage with its teams to determine their individual arrangements.

October 28 In Focus

The next stakeholder meeting is expected to determine whether the two sides can narrow their differences before the Summer 2027 schedule is finalised.

The immediate questions are whether MIAL will provide the detailed refurbishment and capacity information sought by airlines, whether the proposed five-MPPA restriction can be justified against available and planned capacity, and whether a transition plan can be agreed without unilateral changes to airline slots.

For now, MIAL has reiterated the need for a capacity restriction and outlined the options available to airlines. The AOC, however, maintains that no agreement to the proposed traffic reallocation has been reached.