By Tim Hepher

Boston (Reuters) – The chief of Dubai-based airline Emirates aimed to put pressure on Boeing (NYSE) Tuesday for delays to the 777X planeliner. Warning that uncertainty will cause major disruptions to one of the biggest airlines in the world, he said.

Tim Clark of Emirates stated that he would like to have “another mature discussion” with the U.S. aircraftmaker about the timing and design of the twin-engined Jumbo. This is at least two-and-a-half years after its original arrival in June 2020.

We work with precision. Clark stated that Clark struggles with people who don’t achieve this. This was just a few minutes before Clark met Boeing CEOs on the sidelines to an aviation industry summit.

Clark, a veteran of the airline industry, was heavily involved in developing the current 777-3000ER model. This year, Clark has attacked Boeing over the delays it is experiencing with its 777X.

When Reuters reached Boeing, they did not immediately respond.

According to company statements, the company plans to begin delivery of the new, bigger version of the 777 wide body jet late in 2023. However, this is three years later than initially planned due to longer certification processes after the fatal 737 MAX aircraft crashes.

Clark is participating in an International Air Transport Association meeting. He stressed that uncertainty about Boeing’s progress in the program would hinder his complex fleet planning.

Emirates has ordered 126 777X aircraft and is now a launch customer.

Clark claimed that Emirates didn’t know when or whether the first version of its twin-engine jumbo, the 777-9, would arrive.

Clark announced in May that Emirates would not deliver any 777X jets to customers whose contractual obligations were not met. Clark stated Tuesday that he wanted industry contracts modified to increase manufacturers’ liability for delays.

Manufacturers are not liable for product defect, but only indirect consequential damages such as compensation to passengers.

According to the airline’s Chairman, some of the 126 777X planes could be replaced with smaller Boeing 787 Dreamliners.

Emirates already changed its 2019 order for the 777X, cancelling 24 orders as part of an agreement to purchase 30 Dreamliners.

Clark answered Tuesday’s question about whether Emirates would swap more of its 777X aircraft for the 787. This was a matter that will depend upon Boeing.