Every day, about 120 flights take off from Changi Airport bound for Asean capital cities.
This makes Singapore the most connected within the 10-member grouping when it comes to air links between the capitals. Kuala Lumpur is second with about 91 daily flights, followed by Jakarta with close to 70 flights.
Of the region's top five air links by frequency of flights, four are from Singapore; to Kuala Lumpur, Jakarta, Bangkok and Manila.
The fifth is Kuala Lumpur-Jakarta, based on data provided by industry consultancy Sabre and collated by consultancy OAG for advance flight filings by airlines for this month to December.
Air traffic liberalisation, which gives airlines access to more flights and new markets, has been good for Singapore and Changi, said industry experts. There will be more opportunities as the regional bloc continues to push for further liberalisation, they said.
In a recent milestone, Indonesia - the largest country in the group - signed a deal to allow Asean airlines to make unlimited flights to Jakarta.
Indonesia's "yes" after years of reluctance is significant, said aviation law academic Alan Tan of the National University of Singapore.
It follows a decade-long campaign to get the 10 Asean nations to remove all restrictions on flights from their countries and to push to become one aviation market - similar to the European Union's "single sky".
With Jakarta on board, aviation experts expect that other Indonesian cities will follow suit.
The Philippines' capital Manila is now the only Asean capital that has yet to join the agreement, although the country has already removed restrictions on flights by other Asean airlines to its non-capital cities.
The goal is to allow carriers from Asean countries to fly freely within the region by the end of next year.
So Singapore Airlines (SIA), for example, could fly as often as it wanted to any Asean city, instead of being restricted by government-to-government air deals.
The aim is also to allow carriers to fly beyond one capital to another, for example, SIA doing a Singapore-Kuala Lumpur-Bangkok flight.
Ultimately, the benefits of liberalisation are measured in terms of better outcomes for consumers, said Mr Andrew Herdman, director-general of the Association of Asia Pacific Airlines.
In markets like Singapore-Jakarta, Singapore-Kuala Lumpur and Singapore-Bangkok, where liberalisation has led to more flights, including those by budget carriers, consumers have enjoyed fares of under $100 for a return flight - unheard of a decade ago.
Housewife Alice Wong, 49, said: "Holidays used to be a once-a-year or once-in-two-years thing but now it's common for people to take short breaks two, even three times a year because fares, especially for regional flights, are so attractive."