Singapore Airlines is the launch customer of the A350-900ULR and took delivery of its first of the type in September 2018. It was placed in service October 11 on a nonstop service between Singapore and New York Newark Liberty International Airport—the world’s longest route with an average flying time of 18 hr. and 45 min.
There are 13 cabin crew members on board, the same as other SIA A350-900's. In the cockpit there are four pilots, two are captains. The crew has a three-day layover in New York. On one of those days, the crew must be on standby.
(Source: atwonline.com)