The importance of a robust slot allocation process

Ilia Lioutov by Ilia Lioutov | Jul 23, 2019

The majority of passengers this summer will travel through airports with capacity constraints

Global traffic surpassed the 8.8 billion passenger mark in 2018 and ACI’s World Airport Traffic Forecast projects that it is expected to double in 17 years based on a projected growth rate of 4.2% per annum. Over the long term, passenger traffic is expected to grow at an annualized rate of 4.1%, reaching 20.9 billion by 2040. This highlights the need for airports not only to plan for new infrastructure for the long-term but make best use of existing infrastructure to accommodate the demand, especially in the short- and medium-term horizons. Hence, the question of slots—specific time periods allotted for an aircraft to land or take-off—becomes crucial to the issue of scarce airport infrastructure.

2019 Edition of the World Airport Traffic Dataset
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The analyses presented below summarizes current capacity constraints across the globe. and testifies to the importance of robust slot allocation.

Schedule-facilitated and slot-coordinated airports from the traffic perspective

As of June 2019, and with reference to the IATA Summer Season 2019, there are 141 schedule-facilitated (Level 2) and 204 slot-coordinated (Level 3) airports, hence 345 Level 2 and Level 3 airports combined.

These 345 airports handled 5.4 billion in annual passenger throughput in 2018 – 57% of global passenger traffic. When looking at Level 3 airports only, just over half of the worlds’ air routes operate at slot-coordinated airports (IATA Level 3). Annually 45% of global passengers use one of the 204 slot coordinated airports on at least one end of their flight. Asia-Pacific and Europe are the two regions most-affected by slot allocation, where 81 and 183 Level 2+Level 3 airports handled 2.24 and 1.97 billion passengers respectively. In North America, 15 schedule-facilitated and slot-coordinated airports handled over 548 million passengers. Asia-Pacific, Europe, and North America – the biggest aviation markets of the world – were followed by Middle East, Latin America-Caribbean, and Africa, where 20, 29 and 17 Level 2+Level 3 airports respectively handled 282, 280 and 82 million passengers.

Table 1: Number of Level 2 airports by region (IATA Summer Season 2019) and corresponding annual passenger throughput (2018)

Source: List of IATA Level 2 and 3 airports (as of 10 May 2019, extracted 23 May 2019); ACI World Annual Traffic Report 2018.

Table 2: Number of Level 3 airports by region (IATA Summer Season 2019) and corresponding annual passenger throughput (2018)

Table 2: Number of Level 3 airports by region (IATA Summer Season 2019) and corresponding annual passenger throughput (2018)

Contrary to the conventional belief that only large-size airports handle multi-million volumes of passenger traffic, schedule facilitation, and slot coordination it also happens to affect smaller airports. For the sake of a simple convention, small airports handle fewer than one million passengers per annum. ACI analysis reveals that there is a total of 27 small Level 2 airports that handle a total of 12 million passenger per annum. Most of these airports are located in Europe (25) with a corresponding 8 million passengers in traffic throughput. Other nine airports are located in Latin America-Caribbean, Middle East, Asia-Pacific, and Africa – together handling 4 million passengers.

The combined Level 2 and Level 3 airports present the following picture in terms of small airports coverage:

  • Out of 183 Level 2+Level 3 airports in Europe, 34 airports (19%) are small in terms of traffic. Nevertheless, these 34 airports handle a combined of 11.3 million passengers in annual throughput.
  • A similar picture is observed in the Middle East and Africa, where 7 out of 37 airports (22%) are small, yet they handle 4.6 million passengers annually.
  • At the global level, 48 out of 345 Level 2+Level 3 airports (14%) are small. Together, these small airports handle almost 19 million passengers annually.

Table 3: Number of small Level 2 and Level 3 airports combined by region (IATA Summer Season 2019) and corresponding annual passenger throughput (2018)

Table 2: Number of small Level 2 and Level 3 airports combined by region (IATA Summer Season 2019) and corresponding annual passenger throughput (2018)

Airports commit to work together with airlines to improve slot allocation guidelines at a global level

The aviation industry has experienced several fundamental changes over recent years, even though the slot management system was put into place several decades ago. Traditional assumptions regarding airline and airport competition, route development, consumer patterns, fleet decisions, technological disruption, and others have been significantly reviewed.

In 2016 the aviation community agreed to establish an in-depth review of the Worldwide Slot Guidelines, which represents the globally accepted practice to optimize scarce airport capacity through the allocation of airport slots to aircraft operators, to ensure that all stakeholders contribute and benefit from a single global process. The work on the Strategic Review began in June 2018 by creating four task forces with representatives from each of the three industry groups – coordinators, airports, IATA member airlines and non-IATA member airlines – as well as the following associations – the Worldwide Airport Coordinators Group (WWACG), ACI, and the International Air Transport Association (IATA).

More than 80 aviation professionals have worked together to enhance the WSG, comprising of 24 airlines, including low cost, leisure and cargo carriers, 16 airports, and 14 slot coordinator organizations, representing different regions and business models from around the world. The first changes to the WSG resulting from the joint work of airports, airlines, and coordinators in the Strategic Review have been accepted and published in the latest – 9th – edition of the WSG. In 2019 the Strategic Review task forces are continuing their work programme and are committed to delivering constructive proposals on changes and enhancements to the WSG, having in mind the future editions of the WSG – in August 2019 and January 2020.

3 June 2019 marked a new era for airport slot allocation, as ACI World, IATA and WWACG agreed on a new industry-wide governance structure for the WSG that puts the interests of the travelling public at the center of the process. Airport operators, airlines, and slot coordinators will now play an equal role in determining the global guidelines for the allocation of airport slots.

Ilia Lioutov

Ilia Lioutov

Senior Expert, Airport Economics and ESG at ACI Asia-Pacific
Ilia Lioutov is an air transport economist with in-depth expertise in economic and financial performance of airports and is currently a Senior Expert, Airport Economics and ESG at Airports Council International (ACI) Asia-Pacific. His core responsibilities include formulating advocacy strategies at national and international level and representing the airport industry interests within political, economic and regulatory institutions. Lioutov is the secretary for the ACI sub-committee on non-aeronautical revenues and activities (ANARA).
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