Longest duration non-stop scheduled flight

The longest duration non-stop scheduled flight is Singapore Airlines SQ21, which flies between Newark Liberty International Airport in New Jersey, USA, and Singapore Changi Airport. The scheduled duration of the flight is 18 hours 30 mins. The first scheduled flight took place on 11 October 2018, and the airline began daily services on 18 October 2018.

This route was previously operated by Singapore Airlines between 2004 and 2013, but was discontinued for economic reasons. The decision to reintroduce the flight was influenced by changing passenger demand and the introduction of the new Airbus A350-900ULR (Ultra Long Range), which is more cost efficient than the A340-500 that was used on the route until 2013.

The route taken by SQ21 (and its outbound partner, SQ22) vary according to wind and weather conditions. The straight-line distance from Singapore to Newark is 15,344 km (9,534 mi) and passes over the north pole, but the flights typically follow longer routes in order to take advantage of strong tailwinds. For the outbound Singapore-to-Newark flight (SQ22), the aircraft can take advantage of strong west-to-east jet-stream winds over the Pacific Ocean, which means that the scheduled duration of that flight is 1 hour shorter. On the return leg (SQ21), the aircraft can't rely on such strong tailwinds, so it takes longer (despite typically covering a shorter ground-track distance).

The aircraft is configured with 67 business-class seats and 94 premium economy class seats (there is no economy or first-class cabin). Passengers are served several meals during course of the long flight.