IATA deputy director general Conrad Clifford argues that over the past 30 years, the European Slot Regulation has enabled huge benefits for travelers and suggests, ’if it ain’t broke, don’t fix it’.

The global air transport network is a miracle of coordination, planning and organization. Every day, tens of thousands of flights take off and land, connecting every continent of the world. Many of these flights use airports that have become very congested. The demand for the best take-off and landing times exceeds the capacity at many of these airports.

Ensuring that the allocation of these scarce slots is done fairly and transparently is down to the rules and principles of the Worldwide Airport Slot Guidelines (WASG) which have been developed by the Worldwide Airport Slot Board comprising airlines, airports and slot coordinators.

Conrad Clifford

Source: IATA

IATA deputy director general and corporate secretary Conrad Clifford

With more than 40% of passengers going through a slot-coordinated airport, the WASG forms the foundation of international schedules – some airlines have 100% of their flights managed by the slot process, others have more flexibility and only need worry about slots on some of their operation. The WASG is the unsung hero of this system. In the three decades that the WASG have been in operation, more people have been able to fly, more efficiently, at lower cost, to more places than ever before.

Since half the world’s slot coordinated airports are in Europe, let’s look at the European story more closely. The European Slot Regulation was brought in in 1993 to mirror the WASG. Since then, it has been a story of more choice, more competition, and greater efficiency.

Over the period 2009-2019, passenger traffic in Europe grew by 395 million. The pandemic caused it to crash, but it has been rebounding strongly and we expect that it will resume growing again from 2024.

And these passengers have enjoyed ever-greater choice of destinations. Over 5000 routes were added at European airports in the decade from 2009, over half of these came at the most congested (Level 3) airports.

And at the same time, the competition on these routes has also increased. From 2012-2022 the share of single carrier routes has decreased from 72% to 65%, and the share of routes with three or more carriers has increased from 9% to 12%. Low-cost carriers have particularly benefitted: According to ACI Europe, between 2009-2019 LCCs grew 135.6% whereas Full Service Carriers declined by 7%.

And the efficiency has also strongly increased. The capacity utilization at the busiest airports is now around 95-98%, thanks to the discipline of the existing slot rules. And the average number of passengers per flight in the EU has risen from 95 to 121. That is helping to drive down the emissions per passenger too.

Of course, the slot regulation cannot wholly compensate for the increasing congestion at European airports. We must not forget that the core problem here is a fundamental lack of new airport capacity. Nevertheless, within those huge constraints, it is clear that the European Slot Regulation has been and continues to work well, for the aviation industry and more importantly for travelers.

Can it be improved? Yes, in two main ways: the European Slot Regulation should be aligned to stay up to date with the WASG. The WASG has undergone a number of updates in recent years to better reflect changes in market conditions. Regulators in Europe and around the world should consider making sure that their slot regulations match these improvements. For example, the rules for granting half of new slots to new entrant airlines have recently been tweaked to allow more new carriers to qualify.

Secondly, the slot system is built on the first principle of accurate capacity declarations from airports. Post COVID there has been a big disparity between the capacity some airports say they can deliver, compared to the actual capacity when it comes to the operation. If this could be improved then thanks to the WASG we could give travelers even more choice, and deliver even more efficiency.

The EU Slot Regulation turns 30 years old this year. It is a cause for quiet yet emphatic celebration. If it were a person, we would say it was entering the prime of its life. It is a Regulation which has helped deliver huge benefits to European travelers, and is set to deliver more to come. 

About the author: Conrad Clifford is deputy director general and corporate secretary at IATA and is responsible for leading the association’s global advocacy efforts and governance