Air connectivity

Please note that with the 2024 release, the methodology was updated to include all airports in the ACI EUROPE region as the aggregation basis for overall values. In the past, these values included solely ACI EUROPE member airports; therefore values have been occasionally restated resulting in an increased accuracy and overall depiction of the state of European airports' connectivity.

What is exactly air connectivity? How can it be measured? And how well connected is Europe?

ACI EUROPE has now released the Airport Industry Connectivity Report 2024. The Report examines developments in air connectivity, revealing recovery patterns driving aviation structural changes, which in turn reflect a new reality in the market.

This year’s edition reveals that air connectivity recovery keeps lagging behind traffic volumes, with a lack of uniformity across geographies and individual airport markets. It reveals that a mixture of the COVID-19 pandemic and increased geopolitical tensions have significantly challenged air connectivity's resilience. The climate emergency plays a fundamental role, which brings the societal role and value of air connectivity into question, with the report pointing at what the future might hold for Europe from that perspective.

(Find out more about the individual connectivity scores of airports in the Annexes to the Report.)

Using the SEO NetScan connectivity model, the report provides indexes for direct, indirect and hub connectivity based on both quantitative and qualitative metrics. The airport connectivity index is made up of both direct and indirect weekly frequencies, weighted by their quality. This means that this is not simply a measure of how many city pairs there are, or how many direct services there are. For the purposes of this report, connectivity is a composite measure of the number of destinations, the frequency of services and the quality of the connections (in the case of hubbing or indirect services). Let’s begin by outlining the various types of air connectivity that airports facilitate. The following 4 definitions describe them and together they provide a qualitative and quantitative picture of how an airport links to the rest of the world. 


Direct connectivity: These are the direct air services available from the airport – measured not just in terms of destinations, but also factoring in the frequency of flights to the same destination (so for example, an airport with 5 daily flights to another airport, will register a higher score than one with only 4).

Indirect connectivity: This measures the number of places people can fly to, through a connecting flight at hub airports from a particular airport. For example, flying from Cork to a hub airport such as Amsterdam Schiphol is a direct flight from A to B. But with the vast choice of onward destinations you can fly to from there – the large number of available onward connections from these airports expands the range of destinations available from the airport of origin. Indirect connections are weighted according to their quality, based on connecting time and detours involved with the indirect routing. For example, a flight from Manchester to Johannesburg via Paris-Charles de Gaulle will register a higher score than an alternative route via Doha.

Airport connectivity: As the name suggests, this is the most comprehensive metric for airport connectivity – considering both direct and indirect connectivity from the airport in question. Airport connectivity is defined as the sum of direct and indirect connectivity – thus measuring the overall level to which an airport is connected to the rest of the World, either by direct flights or indirect connections via other airports.

Hub connectivity: Hub connectivity is the key metric for any hub airport, big or small. Essentially, it measures the number of connecting flights that can be facilitated by the hub airport in question, taking into account a minimum and maximum connecting time and weighing the quality of the connections by the detour involved and connecting times.

More than 4 years since the onset of the COVID-19 pandemic total air connectivity (direct + indirect connectivity) remains -14% below pre- pandemic (2019) levels. While this is an improvement over last year’s performance (2023 at -16%), air connectivity keeps underperforming passenger volumes — which in Q1 2024 stood at just -3% below pre- pandemic.


Chart 1


Direct connectivity

IST | AMS | LHR on top

Best performance amongst TOP 20 vs. 2019: ATH | IST | PMI

Best performance amongst TOP 20 vs. 2023: SVO | FCO | MUC

1st to Europe: AMS
1st to North America: LHR
1st to Latin America: MAD
1st to Asia-Pacific: ALA
1st to Middle East: IST
1st to Africa: CDG


Hub connectivity is where we see the full value of air transport networks. In simple terms, for an airport that has a wave of 10 flights leaving at 10.00 am, one additional flight arriving at 09.00 am increases its hub connectivity by 10, reflective of the onward connecting options for passengers arriving on that additional flight.

Hub connectivity remains -18% below its pre-pandemic (2019) level this year, and thus keeps significantly underperforming against direct connectivity (-8%). Although the gap has narrowed somewhat over the past 3 years, this has been a consistent pattern in the recovery since 2020 — reflecting structural changes in the aviation market and thus pointing to changed connectivity patterns in Europe.


As was the case last year, 8 European airports are amongst the top 20 global airports for hub connectivity — along with 8 from North America, 2 from the Middle East and 2 from Asia-Pacific.


Frankfurt continues to be the top airport globally for hub connectivity — despite its hub connectivity remaining -23% below its pre-pandemic (2019) level. The airport has held this position every year since 2019 with the exception of 2021.

Dallas Fort Worth (-4%) has replaced Istanbul in the second position this year, but the performance of the Turkish hub remains impressive with its hub connectivity having increased by +37% when compared to its pre-pandemic (2019) level.


Testimony of the changing structure of the European aviation market is the fact that the direct connectivity offered by Low Cost Carriers (LCCs) has expanded by +18% since 2019, while the direct connectivity offered by Full Service Carriers (FSCs) has shrunk by -16%. The same structural dynamic is also evident when looking at the performance of LCCs (+6%) and FSCs (+2%) over the past year.

Overall, the share of direct connectivity offered by hub based airline groups (66%) at the top 6 European hubs has increased when compared to pre-pandemic (2019). The increase of the Lufthansa Group at Frankfurt (from 67% to 71%) and Munich (from 70-73%) is the highest, at the expense of both independent LCCs and other FSCs. Istanbul is the only top 6 European hub where the share of direct connectivity of its hub-based airline group has (slightly) decreased in favour of independent LCCs, although still remains the highest (79%) amongst top European hubs.

Adjusted Connectivity: Power City Access Index

SEO Amsterdam Economics has prepared for ACI EUROPE a measure that combines airport connectivity volumes with service sector linkages and the importance of cities: the Power City Access (PCA) Index.

The Power City Access index combines airport connectivity with its linkages to the service sector and the economic importance of the destinations. Based on the Globalisation and World Cities measure, a global city — also known as a power city, world city, alpha city, or world centre — is a city that serves as a primary node in global economic networks. While it is related to GDP and population, it also emphasises that the importance of a city as a relevant economic powerhouse is not captured by these measures alone. For example, a city in a developing country could be considered a power city if it is important to the origin of connectivity.

Power City Access by airport can provide many insights. Figure 1 gives an example for a few of the main airports in Europe:

  • London-Heathrow has the pole position in Power City Access as a combination of its own dominance in leading corporates’ presence with both quality and direct flights to cities with matching leading corporates of high importance. Only considering direct connectivity, London-Heathrow ranks 3rd.
  • Also boosted by the presence of top level firms, Paris-CDG ranks 2nd by Power City Access while on direct connectivity, the French hub ranks 4th.
  • Amsterdam-Schiphol airport outperforms in direct connectivity, but drops to 3rd place when weighted by access to global Power Cities.
  • Istanbul, while the leader in direct connectivity, takes the 6th position when ranked by Power City Access.