This Friday, one of the world's longest routes will take off for the first time from Houston to Sydney.
United Airlines flight 101 leaves at 8pm for the 8,596-mile trip to Australia’s largest city and is 18 miles longer than the existing Qantas route from Dallas to Sydney.
The new flight, scheduled to take 17 hours and 30 minutes, arrives at 6.30am local time, two days after leaving Houston, with a day lost because of the International Date Line. But on the return journey, passengers will arrive 75 minutes before they set off, local time. Departure is at 11.50am, with arrival at 10.35am the same day.
Last year, the world's longest commercial flight - between Doha and Auckland - touched down for the first time in February. And on 25 March 2018, Qantas starts the first non-stop scheduled service from London Heathrow to Perth. The two airports are 9,009 miles apart, which will make it by far the longest non-stop flight from the UK. Here are 10 of the world's longest flight routes.
Doha to Auckland
The Qatar Airways AR920 route between Doha and Auckland is the longest distance (9,032 miles) between two cities. The first flight took off in February 2017, flying across 10 time zones, with four pilots and 15 crew members serving 1,100 cups of tea and coffee, 2,000 cold drinks and 1,036 meals on board.
The flight took 16 hours and 23 minutes on the outbound journey and 17 hours and 30 minutes on the return leg.
Dubai to Auckland
Prior to the introduction of Qatar Airways' Doha-Auckland route, the UAE's Emirates held the record for its service from Dubai to the New Zealand city with a route of 8,824 miles.
Los Angeles to Singapore
United Airlines' UA 37 became one of the world's longest flight routes in October 2017, travelling 8,770 miles between California and Singapore.
Dallas to Sydney
Prior to United's recently announced Houston to Sydney route, Qantas' AF 8 service between the cities of Dallas and Sydney, which travelled 8,578 miles, was the longest US-Australia flight.
San Francisco to Singapore
Both Singapore Airlines and United Airlines have run services between San Francisco and Singapore (8,447 miles).
Expected to take 17 hours and 55 minutes, United Airlines' maiden voyage arrived after only 16 hours thanks to low air resistance.
Johannesburg to Atlanta
The only African entry on the list, Delta Air Lines' route between Johannesburg and Atlanta, Georgia, covers 8,439 miles and was first launched in June 2009. The journey takes just under 17 hours.
Abu Dhabi to Los Angeles
Etihad Airways began running a service between Abu Dhabi and Los Angeles (8,372 miles) in June 2014.
Dubai to Los Angeles
Rival airline Emirates operates a service from Dubai to Los Angeles that is slightly shorter, at 8,321 miles.
Jeddah to Los Angeles
The only entry on the list from airline Saudia connects passengers from Los Angeles (8,315 miles) with the coastal city of Jeddah in Saudi Arabia. Jeddah is the gateway to both Mecca and Medina, with the route's launch significantly improving access to the religiously important cities for Islamic passengers from the US.
Doha to Los Angeles
At 8,288 miles, Qatar Airways' Doha to Los Angeles QR 739 service is one of the longest in the world and the Australian airline's third entry in the top 10.