ACI World steps up campaign to modernise ‘outdated airport slot system’

ACI World today released a white paper calling for the modernisation of the global airport slot allocation system.

A fierce critic of the current system for a number of years, the association’s white paper details how an outdated regulatory framework, designed more than 50 years ago, is forcing the aviation industry into inefficient compromises, creating barriers to socio-economic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.

Its argument is simple, the foundational framework managing slot allocation has not kept pace with aviation’s dynamic growth and transformation.

And 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,” states 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“Airports are doing their best to operate within an outdated regulatory framework, but the reality is that these inflexible rules and practices are preventing the industry from adapting to modern passenger demands,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.

Justin Erbacci. Photo By Joshua Sudock.

“ACI World urges regulators to sit down with the industry and finally deliver the overdue upgrade that our passengers deserve.”

It is certainly not the first time the association has called for change, but it warns that the scale of the challenge is significant and needs to be addressed now.

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.

ACI states: “Airports are critical infrastructure, built to serve their communities and the travellers. This 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. ”

ACI World believes that far from dismantling stability, a modernised framework would make the system more adaptable, so that scarce capacity can respond to how aviation and the communities it serves actually develop.

Erbacci adds: “Airports are ready to do the work, but we cannot build the future of aviation alone.

“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.”