As many of us know, the longest non-stop commercial flight in the world operated between Singapore and New York with flight number SQ21. This flight was operated by Airbus A340-500 and the flight duration was about 19 hours. Why did Singapore Airlines decide to cancel this route?

  • 3
    for cost reasons, of course.
    – user428517
    Commented Sep 22, 2015 at 21:42
  • Because it was the longest flight in the world. If running long flights was a no brainer (technically and economically) many people would run flights as long or longer than this one.
    – Relaxed
    Commented Sep 22, 2015 at 21:45
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    Some discussion on this here: bloomberg.com/news/articles/2015-06-17/… A big potential issue is fuel: You need to burn a lot of fuel at take off to get the fuel for the next 19 hours up in the air.
    – Hilmar
    Commented Sep 22, 2015 at 21:50
  • 1
    @Hilmar: And as a followup to your comment, see Why don't airliners use in-air refueling systems?. Commented Sep 22, 2015 at 22:01
  • Really? I thought it would be longer by now. In 2012, I took a 19h26m flight from Toronto to Hong Kong. It was the longest flight at the time but I thought there would be some 20-21 hours ones by now.
    – Itai
    Commented Sep 22, 2015 at 22:22

2 Answers 2


It was fairly widely reported that fuel costs made the flights uneconomical. The maintenance of the A340-500s SIA retained specifically for the flight also contributed, as they only had five A340-500s.

Sample quotes:

It is widely known in the industry that SIA’s A340-500 non-stop flights to the U.S. are unprofitable, because of the four-engined aircraft’s higher fuel burn. Some SIA executives were also questioning why the carrier was going to the trouble of maintaining such a small fleet of A340s.


Snyder and most other experts suspect the airline got tired of dealing with poor profit margins on the fuel-guzzling four-engine Airbus A340. "They do use a ton of fuel, and that's always painful," says Snyder.



Just to add that this flight was revived by SIA in October 2018 but with the more fuel-efficient A350 (previously the A340 was used).


The first new non-stop flight between Singapore and New York departed Changi International Airport on 11 October 2018 at 2337hrs (SIN time) and arrived at Newark Liberty International Airport a day later, at 0529hrs (US Eastern time). The flight duration was 17 hours 52 minutes.

Nikkei Asia (2018):

This time, Singapore's flag carrier counts on an ultralong-range version of the fuel-efficient Airbus A350-900 jet to cut fuel costs ...

Singapore Airlines debuted a direct flight to New York in 2004, but surging crude oil prices forced the carrier to scrap the route five years ago [2013]. The four-engine Airbus 340-500 consumed too much fuel and crude prices were running high, at above $100 per barrel. Meanwhile, the economic slump that followed the global financial crisis stunted demand for business travel.

Now, with the world economy in better shape, one airline after another in the Asia-Pacific region is adding new long-haul flights.

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