It may continue to be capacity constrained, but London Heathrow still retains world’s most internationally connected airport title

How many new airport runways have been built across the world since it was first identified that London – and especially Heathrow Airport – was in urgent need for additional runway capacity? It is hard to tell… there have even been double-digit numbers of new major international airports constructed. However, Europe’s largest hub remains the most internationally connected airport in the world, topping the annual Megahubs International Index from flight information intelligence provider OAG for a second straight year.


  • London Heathrow ranks as the most internationally connected airport across the globe for the second straight year in the 2018 Megahubs Index from OAG;
  • Chicago O’Hare is the second most internationally connected airport in the world; increasing its Connectivity Index by 11 points over last year;
  • Singapore Changi is the most-connected Megahub in the Asia Pacific and the third most-connected among low-cost international Megahubs;
  • The Asia Pacific region secured ten of the top 25 positions in the Low-Cost International Megahub category.

The Megahubs International Index 2018 reveals the world’s top 50 most-connected airports for international services, as measured by the highest ratio of scheduled connections to the number of destinations served.

London Heathrow scored a Connectivity Index (CI) of 333 – 27 points higher than the second most connected international airport, Chicago O’Hare. On its busiest day over the past year, there were over 66,000 possible international connections between flights arriving and departing London Heathrow within a six-hour window. British Airways was the dominant carrier, controlling 52%  of flights at the airport over the past year.

“Megahubs are incredibly important for the global travel ecosystem. They increase efficiency, competition and choice, and most importantly, create a boundary-less world for travellers,” says John Grant, senior analyst at OAG.

“Heathrow is a key connection point for flights all over the world due to its proximity to key EMEA markets and North America.  Expansion opportunities will eventually strengthen the airport’s position as the leader in global connectivity by increasing capacity and service to both emerging markets and key European destinations,” he adds.

The index is generated by comparing the number of scheduled connections to and from international flights with the number of destinations served from the airport. It is determined by calculating the total number of all possible connections between inbound and outbound flights within a six-hour window, where either the inbound, outbound, or both flights are international on the busiest day for global aviation over the 12 months to July 2018.

TABLE – The top International Megahubs are those airports with the highest ratio of possible scheduled international connections to the number of destinations served by the airportSource: OAG Megahubs International Index 2018

Chicago O’Hare is the second most internationally connected airport in the world; increasing its Connectivity Index by 11 points over last year and moving up to second in the ranking, with Frankfurt, Amsterdam Schiphol and Toronto Pearson completing the top five.

OAG’s Megahubs International Index goes beyond the size of an airport’s route network. While Dubai International may be the world’s largest international airport by passenger demand and a major connecting hub for global air travel it is only ranked 18th in the analysis.

Similarly, Beijing Capital International is the largest airport in the world in terms of scheduled airline capacity (seats), but only has half the number of possible international connections on the busiest day, taking its ranking down to 32. Shanghai Pudong Airport may be smaller than the Beijing hub in scale, but achieves a higher position in the International  because there are more possible connections for each destination.

However, looking ahead, all eyes will be on Beijing’s new Daxing airport, which is likely to boost connectivity options in the Chinese capital.  “With eight runways serving 100 million passengers annually, we expect it to become one of the busiest and most internationally connected hubs in the world,” highlights Mr Grant.

This is one global ranking with the top positions not dominated by Asia, albeit six airports from the region do make it into the top 15 International Megahubs, the largest being found in South East Asia – Singapore Changi (8th), Jakarta Soekarno–Hatta International (10th), Kuala Lumpur International (12th), Hong Kong (13th), Bangkok  Suvarnabhumi (14th) and Seoul Incheon (15th).

But the Asia Pacific region does dominate in the Low-Cost International Megahub category, securing ten out of the top 25 positions. The top three spots for low-cost connections stayed the same from 2017 to 2018, with Kuala Lumpur International ranking first, followed by Jakarta Soekarno–Hatta International and Singapore Changi.

Of particular note Manila’s Ninoy Aquino International jumped from 12th to fourth, while Bangkok Don Mueang International rounded off the top five positions; Barcelona El Prat was the highest ranked non-Asian airport on the list; and Fort Lauderdale Hollywood International was the highest placed airport in the Americas having risen from 14th to 9th in the rankings.

TABLE – Airports across Asia dominate in OAG’s Low-Cost International Megahub category and hold the top seven positionsSource: OAG Megahubs International Index 2018