Istanbul is the world’s most connected airport; four from China among top 20

Geography prevents some airports from becoming larger hubs despite having a high proportion of connecting passengers. These airports become specialist transfer facilities for the local airline, while also creating some economic benefit

The most connected airports in the world are important for a number of reasons, including global business; these airports are vital for global business travellers with a wide range of international and domestic flights; economic growth as air connectivity can help a country's economy grow by attracting business investment and human capital, and stimulating tourism; and global markets where well-connected airports can help companies access global markets, making them attractive locations for setting up new ventures and subsidiaries. Airline operations will facilitate pragmatic traffic connectivity because it helps fill empty capacity, reduces reliance on only a few global markets, and can provide high yields for obscure connections. When it comes to global connectivity, these airports play a key role in facilitating seamless travel and enhancing global connectivity.

Connecting passengers are an important part of business for both airports and airlines. Although short connecting passengers are less likely to spend significant amounts compared to local holidaymakers seeking a tax-free bargain before their trip, for airports the benefits, such as additional passenger fees, modest non-aeronautical revenues, and the value of extra flights, make connecting traffic worthwhile. For airlines, connecting traffic can determine if a route is viable or not, and can even influence the frequency of flights; such as increasing from four to six flights a day.

At the top of the connecting market food chain are airports known as Megahubs. They include London’s Heathrow, Kuala Lumpur, Chicago O’Hare, Istanbul and Dubai. These airports typically host large legacy airlines with extensive networks of short and long-haul flights connecting passengers from one continent to another.

Traditionally these Megahub airports operate at near maximum capacity, with connecting passengers passing through the airport at all times of the day, and they are frequently expanding with new terminals and runways. The scale of a Megahub can vary; some may have flights to literally hundreds of destinations every day, while others may serve a smaller number of destinations but with a very high frequency. Once established, the airport becomes a fortress for local airlines, attracting more connecting passengers with every new flight added to the operation. For airlines, the ability to ultimately pick and choose from where they want to carry connecting traffic becomes a key part of their business strategy. With a slightly smaller network, mass hub airports are still in themselves large and important creators of economic activity for both the local region and, in some cases, the whole country. Hub airports may handle fewer passengers per annum, have a slightly lower range of connecting destinations or flights per day, but are still well-established and popular connecting points. Examples of hub airports include Amsterdam, Munich, Madrid and, more recently, Tokyo Haneda.

Geography prevents some airports from becoming larger hubs despite having a high proportion of connecting passengers. These airports become specialist transfer facilities for the local airline, while also creating some economic benefit.

Ultimately, passengers need to connect somewhere, at some point, as they travel and sometimes they may have a choice of which airport to use, or on other occasions may be limited to one particular airport due to available connections. All hub airports provide valuable connections, and some will continue to grow further in the coming years. Interestingly, some hub airports may not want to become Megahubs as they are content handling their current traffic and airline customers rather than be constrained by other competitive factors.

Having the world’s largest list of destinations but with only one flight a day to each would be impressive, but as in many things it is the combination of destination variety and flight frequency variables that differentiates the megas from the hubs.

Cirium’s list of the top 20 most connected airports during the first half of 2024 found that Turkey’s main hub Istanbul served 309 destinations, followed by Frankfurt with 296 routes and Paris CDG (282).

Amsterdam’s Schiphol airport was joint fourth with 270 destinations, which tied it with Chicago’s O’Hare, the top US gateway. The only other European airport in the top 10 was Rome Fiumicino (234 routes).

No UK airport features in the top 10 with London Heathrow dropping from eighth position in 2023 to 12th this year with 221 destinations. This placed it only just ahead of another London airport Gatwick which served 218 destinations. Madrid, Munich and Barcelona airports also featured in the list.

Cirium’s research shows that 10 of the top 20 most connected airports were in Europe with four each in China and the US, and two in the Middle East – Dubai International and Jeddah in Saudi Arabia.