SINGAPORE, 16 September 2026: Airports Council International (ACI) World, the trade association of the world’s airports, has released a white paper calling for the modernisation of the global airport slot allocation system.
The white paper explains how an outdated regulatory framework, designed more than 50 years ago, is forcing the aviation industry into inefficient compromises and creating barriers to socio-economic competitiveness and connectivity.
It argues that the 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 ACI World Director General Justin Erbacci. “Airports are doing their best to operate within an outdated regulatory framework, but the reality is that these inflexible rules and practices are preventing the industry from adapting to modern passenger demands,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 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.
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 http://aci.aero/airport-advocacy/airport-slots/
About ACI
Airports Council International (ACI), the trade association of the world’s airports, is a federated organisation comprising ACI World, ACI Africa, ACI Asia-Pacific and Middle East, ACI EUROPE, ACI Latin America and the Caribbean and ACI North America.
(Source: ACI)
