Four of the airports ranked as the worst in the world are based in the UK, according to a study published on Tuesday by AirHelp, a technology company that provides legal services to airline passengers.

Of the 76 airports in the survey, Singapore’s Changi was the best according to the rankings, followed by Munich International Airport and Hong Kong International Airport.

Here are the top 10 airports in the world and their scores in the AirHelp index:

  1. Singapore Changi 9.07
  2. Munich, Germany 8.66
  3. Hong Kong 8.42
  4. Copenhagen Kastrup, Denmark 8.04
  5. Helsinki-Vantaa, Finland 8.03
  6. Cincinnati-Northern Kentucky, USA 7.94
  7. Barcelona El Prat, Spain 7.90
  8. Madrid Adolfo Suarez-Barajas, Spain 7.81
  9. Auckland, New Zealand 7.80
  10. Frankfurt, Germany 7.76

Heathrow, the third busiest airport in the world by international passenger traffic, ranked in the top 20.

However, across the UK more generally, Gatwick, Manchester and Stanstead were in the bottom five. Edinburgh’s airport was the sixth worst in the world.

“Gatwick recognises the inconvenience that delays cause to our passengers and we will continue to do everything possible to prevent them from occurring,” said a Gatwick Airport spokesman.

‘However, over recent years repeated strike action on the continent and heavily congested airspace above parts of Europe and London, have led to a significant increase in the number of delays caused by wider air traffic control issues outside Gatwick’s control,” he added.

The rankings also looked at airlines, with British Airways in seventh place worldwide out of 87 carriers, followed by Virgin Atlantic.

Singapore Airlines took the title for the best carrier in the world followed by Bulgaria Air.

How were the airports ranked?

1. On-time performance

“We pull the on-time departure statistics for flights departing from the airport for the last season to determine how likely they are to depart on time,” AirHelp said.

2. Quality of service

3 Things That Will Change the World Today

“This rating, from Skytraxresearch.com, factors in hundreds of metrics and details to give us a measure of an airport’s quality of service, from terminal comfort to passenger facilities to check-in and security,” Airhelp said.

3. Passenger sentiment 

“This rating takes into account how passengers express sentiment about their experience traveling through the airport on Twitter,” AirHelp said.