Plans to invest nearly €4.5 billion ($5 billion) in expanding Adolfo Suárez Madrid-Barajas Airport (MAD) are moving forward as Spain’s airport operator Aena seeks to prepare the capital’s main gateway for long-term traffic growth—while tensions with airlines over airport charges continue to escalate.

The proposed expansion formed the focus of discussions at a meeting of the Madrid Airport Coordination Committee, chaired by Benito Núñez Quintanilla, Spain’s secretary general for air and maritime transport. The meeting reviewed Aena’s proposed Airport Regulation Document (DORA) for the 2027-31 period, which outlines investments across airports in the Madrid region totaling €4.49 billion.

The plan centers primarily on MAD, where several major infrastructure projects are proposed. They include the expansion of terminals T4 and T4S, construction of a new passenger processing building and renovations to the departure areas of terminals T1, T2 and T3.

Aena also plans to prepare the airport for improved intermodal connectivity, including infrastructure to accommodate future high-speed rail and new metro links.

Additional investments will focus on road access, parking areas and aircraft stands to improve accessibility, passenger capacity and operational flow across the airport. Airfield upgrades are also included, although Aena says the airport’s runway system will not require expansion.

“The capacity of the four existing runways is sufficient to handle future needs,” the company says, describing this as an advantage for MAD compared with competing European hub airports that face greater infrastructure constraints.

The expansion program forms part of Aena’s broader investment cycle planned under the next regulatory framework. Across its Spanish airport network, the company intends to invest nearly €10 billion in regulated infrastructure projects between 2027 and 2031, with total investments—including non-regulated activities—reaching about €12.9 billion. Aena says the planned airport charge increase tied to these investments would average €0.43 per passenger annually.

“The fact that investments have been ‘unfrozen’ is essential for the sustainable progress of airports and consequently of regions, because air transport infrastructures cannot stand in the way of progress and mobility,” Aena Chairman and CEO Maurici Lucena said when announcing the investment plan earlier this year.

However, the proposal has triggered strong criticism from airlines and industry groups.

On March 3, IATA called for Spanish airport charges to be reduced by 4.9% annually between 2027 and 2031, arguing that traffic growth should enable Aena to fund its investments without raising fees.

In a sharply worded statement, IATA Director General Willie Walsh rejected comments from Lucena suggesting that airline calls for lower charges could affect safety. “Safety is the number one priority of airlines and the whole aviation industry,” Walsh said. “That the chairman of Aena would misunderstand this is yet another indication that he is isolated from the fundamental realities of aviation—including both safety and economics.”

Walsh added that linking airline concerns about charges with safety was “highly inappropriate and shows the flimsy grounds Aena have for justifying their request for a 16% charges increase.”

IATA also argued that Aena has generated excessive returns under the current regulatory framework.

“Aena has gamed the regulatory system for years, earning millions of euros more than it should have, at the expense of passengers, airlines and the Spanish economy,” said Rafael Schvartzman, IATA’s regional vice president for Europe.

Aena strongly rejected the accusation, saying the claim is unfounded and pointing instead to the impact of the COVID-19 pandemic on its finances. According to the company, airport charges have declined over the past decade.

“Since 2015, Aena’s airport charges have been reduced by 7% in nominal terms, which represents a 37% reduction in real terms when inflation is taken into account,” the operator said in a statement responding to IATA.

The dispute follows a separate confrontation with Ryanair over airport fees. In September 2025, the Irish ULCC said it would cut more than 1 million seats from its winter 2025-26 schedule in Spain, including closing its base at Santiago de Compostela Airport and withdrawing service from several regional airports. Ryanair said the move was a response to what it called “excessive and uncompetitive” airport charges imposed by Aena.

Aena dismissed the criticism, accusing the airline of using pressure tactics to secure concessions. “Ryanair’s communications and institutional relations policy is in permanent and deliberate conflict with objective facts and truthfulness,” Lucena said at the time.

The proposed DORA plan will now undergo further regulatory review before the final framework for airport charges and investments for the 2027-31 period is approved.