Aena has ruled out backing the proposal to turn Casarrubios del Monte into a second commercial airport for Madrid, citing operational and airspace compatibility concerns. Executive vice president Javier Marín presented the decision at a July 2026 analyst conference, as the company outlined plans to raise Adolfo Suárez Madrid-Barajas Airport’s capacity to 90 million passengers annually.
Marín said Casarrubios’s location presents complex challenges. The area already sees heavy traffic from Barajas and Cuatro Vientos, with other nearby aerodromes adding to the load. Integrating a new commercial airport would require coordinating how aircraft approach and leave along existing flight paths, potentially disrupting current operations. Cuatro Vientos is particularly close: its southwest departures intersect with Casarrubios airspace, just 25 kilometers away. Changes would require a large overhaul of flight procedures while keeping routes clear of urban areas.
Private Project Scaled Back
The private consortium Air City Madrid Sur has scaled back its original 2018 proposal, aiming to avoid classification as an airport of general interest. The revised plan would extend the current runway to 1,800 meters and add a new 3,200-meter runway. It also includes a terminal designed for up to one million passengers per year. The project carries an estimated investment requirement of €400 million and remains under review by the Interministerial Defense-Transport Commission.
To operate as a public-use commercial airport, the project would need public-use status and certification from Spain’s aviation authority, AESA. It would also need a master plan and permits covering environmental and urban-planning matters. A basic technical question is whether its flight procedures can coexist with Madrid’s surrounding airspace and nearby aerodromes, a matter for assessment by the competent aviation and defense authorities. Aena’s objections create a impressive technical obstacle, even as the proposal continues through the relevant review process.
Barajas Expansion Takes Priority
Rather than back a second airport, Aena is pressing ahead with plans to expand Barajas. Marín said the airport’s four runways can theoretically handle up to 120 operations per hour; he identified terminal processing capacity as the basic bottleneck. Aena’s strategy centers on enlarging terminals T4 and T4S, adding aircraft stands and modernizing existing facilities. The proposed investment of more than €4 billion is intended to raise annual capacity from roughly 70 million to 90 million passengers.
The Barajas project forms part of Aena’s proposed third Airport Regulation Document, or DORA III, covering 2027-2031. The network-wide program is estimated at about €12.9 billion, with Barajas and Barcelona’s El Prat among its basic expansion priorities. Aena chairman and chief executive Maurici Lucena has described the plan as a multi-year investment program focused on expanding those two airports. It is expected to undergo review by Spain’s Directorate General of Civil Aviation and the National Commission on Markets and Competition before reaching the Council of Ministers.
On July 30, Aena approved contracts worth €146.47 million for the T4 North Platform and T4S South Pier, both included in the DORA III program. In the first half of 2026, Barajas handled 34.06 million passengers, up 4.2% year on year. June alone saw more than six million travelers and nearly 39,000 aircraft movements. Aena reported 6,466,823 passengers at Barajas in July. Across its airport network, the company recorded 225.5 million passengers in January-August 2026, a 4.1% increase year on year, while aircraft movements rose 4.4% to 1.89 million.
The proposed investment program also has implications for airport charges. The average passenger tariff is projected to rise from €10.52 in 2026 to €12.69 in 2031, equivalent to about 3.8% annual growth. Javier Gándara, president of the airline association ALA, has described the broader plan as roughly €13 billion in investment, including about €10 billion in regulated aviation investment financed through airport charges rather than direct taxpayer funding. Those figures remain part of a proposal subject to regulatory and governmental approval.
Debate Over Future Demand
Backers of the Casarrubios project argue that Madrid’s air traffic growth will eventually outpace even an expanded Barajas, particularly as demand grows for point-to-point flights and low-cost carriers, alongside cargo and executive aviation. They also say smaller aircraft could require more frequent movements to carry the same number of passengers. Aena plans to add capacity at its established hub, where terminals, runways and airline operations are already integrated. The company maintains that planned upgrades can meet foreseeable demand, including during peak hours.
The expansion also aligns with Iberia’s reported plan to grow its fleet from about 120 to 150 aircraft, including additional long-haul aircraft. Javier López Solás, an Iberia commercial executive, has described Madrid as having an exceptional chance to grow within Europe’s airport network, while emphasizing that investment must be matched by improvements to services and infrastructure. The capacity increase at Barajas so matters to Aena’s network planning and Iberia’s long-haul and Latin American connectivity strategy.
Madrid-Barajas has historically accommodated growth through successive runway and terminal expansions, followed by added aircraft stands and cargo capacity. Earlier plans included a 4,400-meter runway alongside additional terminal and cargo infrastructure, reflecting a long-standing policy of concentrating Madrid’s commercial aviation growth at the existing hub. Aena’s current plan continues that model on a much larger scale. Madrid Sur’s future, meanwhile, depends on further technical assessments and government approvals, particularly on airspace compatibility. The private project remains under review, while work on the Barajas expansion has begun, with construction underway at T4 and T4S. Marín’s remarks came during Aena’s first-half results presentation, as the company reaffirmed its focus on consolidating Madrid’s air traffic at Barajas rather than dividing it between two airports.
