The Airbus A350 is an ideal widebody twinjet commercial aircraft for airlines looking to operate efficient ultra-long-haul flights with enough space on board to both accommodate industry-leading premium cabins and give economy passengers room to breathe. These qualities, and more, have seen the type become Delta Air Lines’ intercontinental flagship, and it operates routes as long as 17 hours.

But which destinations do the longest of these corridors serve, and from which Delta Air Lines hub airports? Using data made available by Cirium, an aviation analytics company, let’s examine the SkyTeam founding member’s longest A350 routes by block time from June 2026 onwards. It is worth noting that all of them use the smaller A350-900 model, as Delta is yet to receive any of its A350-1000s.

South African Routes Sit At The Top Of The List

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Both first and second place on this list are routes from South Africa back to Hartsfield-Jackson Atlanta International Airport (ATL). This facility in the US state of Georgia serves as the main hub for Delta Air Lines, and it is the busiest airport in the entire world by passenger numbers. Delta’s very longest Airbus A350-900 route links it with Johannesburg OR Tambo International Airport (JNB).

Indeed, Cirium’s data shows that this lengthy intercontinental corridor clocks in at a maximum scheduled block time of 17 hours and five minutes in the westbound direction. This puts it half an hour ahead of Cape Town (CPT), whose Delta A350 flights back to Atlanta take up to 16 hours and 35 minutes. Per Big Ambitions, the CEO of South African Tourism, Sthembiso Dlamini, said about the Johannesburg route:

“North America is a key market for us, and we are confident that this Delta non-stop flight will boost South Africa’s efforts to grow business and leisure tourists’ arrivals out of this market.”

The Best Of The Rest

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Most of the rest of Delta Air Lines’ longest scheduled passenger flights with the Airbus A350-900 by maximum block time from June 2026 onwards are transpacific corridors that cross the International Date Line. The only exception is the route from Riyadh (RUH) in Saudi Arabia back to Atlanta, which will start in October. Guests flying westbound can expect a maximum duration of 15 hours and 35 minutes.

Delta’s longest transpacific flight with the A350, and its third longest overall, comes in the form of the westbound rotation from Detroit Metropolitan Wayne County Airport (DTW) to Shanghai Pudong (PVG), at 16 hours and 15 minutes. This puts it just ahead of the 16 hours and 10 minutes that it can take to fly from Los Angeles (LAX) to Melbourne (MEL), while Atlanta to Seoul (ICN) can last up to 16 hours.

Next up is a new route, namely the corridor from LAX to Hong Kong (HKG) that started this week and will have a maximum westbound block time of 15 hours and 45 minutes. Another lengthy Delta A350 route from LAX is the corridor to Sydney (SYD), which tops out at 15 hours and 20 minutes, putting it just behind Detroit to Seoul. Indeed, that corridor has a maximum block time of 15 hours and 30 minutes.

What’s It Like On Board?

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According to present fleet data made available by ch-aviation, Delta Air Lines currently has a grand total of 41 examples of the Airbus A350-900 at its disposal. These modern widebody twinjets are just 5.7 years old on average, compared to a fleet-wide mean figure of 17 years, and it also has another 18 examples of the type on order. These aircraft will eventually be joined by 20 stretched A350-1000s.

aeroLOPA shows that Delta has two seating layouts on its A350-900s. The higher-density version features 32 Delta One flatbeds, 48 Premium Select recliners, and 226 economy seats (36 with extra legroom) for a total capacity of 306. However, the lower-density 275-seat setup (40 Delta One flatbeds, 40 Premium Select recliners, and 195 economy seats) is more likely to be used on ultra-long-haul flights.