Airports Council International World Calls for Modernisation of Outdated Airport Slot System Stifling Competition and Costing Passengers

The trade association of the world’s airports is calling for a modernised, transparent and collaborative approach to ensure scarce airport capacity is used efficiently, market access remains competitive and slot allocation keeps pace with increasing passenger demand.

Montreal, 15 July 2026 – Airports Council International (ACI) World, the trade association of the world’s airports, today released a white paper calling for the modernisation of the global airport slot allocation system. The white paper details how an outdated regulatory framework, designed more than 50 years ago, is forcing the aviation industry into inefficient compromises, creating barriers to socio-economic competitiveness and connectivity.

The foundational framework managing slot allocation has not kept pace with aviation’s dynamic growth and transformation. With the number of the world’s most congested, slot-restricted airports surging by over 25% in the last decade alone, and global passenger traffic projected to nearly double by the mid-2040s, the capacity crisis continues to accelerate. ACI World is calling on regulators to engage with the industry to address the issue and modernise the slot allocation system before the capacity crunch escalates further.

“We are trying to run a 2026 aviation industry on a 1970s operating system,” said Justin Erbacci, Director General of ACI World. “Airports are doing their best to operate within an outdated regulatory framework, but the reality is that these inflexible rules and practices are preventing the industry from adapting to modern passenger demands, providing competitive fares and building resilient networks. ACI World urges regulators to sit down with the industry and finally deliver the overdue upgrade that our passengers deserve.”

ACI World warns that the scale of the challenge is significant. The white paper Airport Slot Policy – Rethinking Airport Access in a Capacity-Constrained World outlines how the current system affects stakeholders across the aviation ecosystem.

Airports are critical infrastructure, built to serve their communities and the travellers. That makes decisions about their limited capacity a matter of public interest, not just an operational detail. A small number of airports carry most of the world’s air traffic. Fewer than 10% of the world’s airports handle nearly two-thirds of all passengers, and 85.5% of the busiest ones, those serving more than 40 million passengers a year, are already operating at or near full capacity. Yet today’s system offers little visibility into how decisions about that scarce capacity are actually made. As pressure on these airports keeps growing, airports, airlines and policymakers need to be able to see and evaluate those decisions. A modernised system should make that possible by providing greater transparency around who is requesting access, who receives it and why, so that the infrastructure is used efficiently and in everyone’s interest.

The current system makes it difficult for the market to evolve, limiting competition and consumer choice, and ultimately reducing the quality of connectivity. At the 50 most congested airports, the four largest airlines account for 67% of flights. Historic access rights accumulate over time and are rarely released. Existing guidelines heavily prioritise historical allocation patterns and incumbent airlines. This makes it challenging for the system to adapt as passenger demands or economic needs change. A modernised framework would not dismantle stability. It would make the system more adaptable, so that scarce capacity can respond to how aviation and the communities it serves actually develop. ACI World believes that defending a 50-year-old status quo is the real risk to network stability and growth, but the scale of change needed cannot happen in silos.

“Airports are ready to do the work, but we cannot build the future of aviation alone,” added Erbacci. “We strongly urge airline representatives and legacy industry bodies to move past historical resistance and a ‘zero-sum’ mentality and join us in improving the slot allocation system. It is time to design a transparent, future-ready framework that unlocks operational efficiency, fosters healthy competition, and delivers the routes that the 21st-century global economy demands.”

To download the full white paper and learn more about the critical need for slot allocation modernisation, visit store.aci.aero and https://aci.aero/airport-advocacy/airport-slots/

About ACI

Airports Council International (ACI), the trade association of the world’s airports, is a federated organization comprising ACI World, ACI Africa, ACI Asia-Pacific & Middle East, ACI EUROPE, ACI Latin America and the Caribbean and ACI North America. In representing the best interests of airports during key phases of policy development, ACI makes a significant contribution toward ensuring a global air transport system that is safe, secure, efficient, and environmentally sustainable. As of January 2026, ACI serves 811 members, operating over 2,200 airports in more than 160 countries worldwide.