https://phys.org/news/2018-05-singapore-airlines-world-longest-flight.html

The current record holder is Qatar Airways Flight 921 from Auckland to Doha, which takes 17 hours 40 minutes.

The Singapore Airlines flight will use the long-range Airbus A350-900ULR, which will be configured to carry 161 passengers—67 in business class and 94 in premium economy.