Emirates won’t yet commit to ordering the largest variant of Airbus SE’s flagship A350 jet, even after engine-maker Rolls-Royce Holdings Plc said it was modifying parts of the turbines to make them more reliable.

The carrier, which has orders for 270 of Boeing Co.’s rival 777X model, will make a decision on whether or not to order the model after it determines whether the improvements to engine-components made by Rolls-Royce hold up to scrutiny, Adnan Kazim, Emirates’ deputy president and chief commercial officer, said in an interview in Doha on Tuesday.

Emirates is among the world’s largest long-haul carriers and has historically been the biggest buyer of Boeing’s previous generation 777 and Airbus’ double-decker A380. While the airline has ordered 73 of the smaller A350-900 variant, a purchase for the -1000 variant that is capable of flying 9,100 nautical miles, has been elusive.

Tim Clark, the outspoken president of Emirates, has previously described the Rolls-Royce Trent XWB-97 engines that power the A350-1000 as defective and didn’t meet its durability specifications. Rolls-Royce has since said it has made improvements to the engines to increase time-on-wing and reliability in hot and dusty climates.

The airline continues to plan for deliveries of the long-delayed 777X to begin in the second quarter of 2027, Kazim said. The 777X was originally due to enter into service in 2020, and the planemaker has said it still expects to start handing over jets to customers sometime next year. The plane has yet to receive regulator approval to begin the next phase of certification testing while it works through a durability issue with GE Aerospace-built engines.

Kazim sees the long-term trend toward travel demand offsetting the impact from the current geopolitical tensions in the Middle East. “We learn how to maneuver, how to keep going,” Kazim said.