Everett, Washington: Boeing Co said on Monday three new aircraft models under development — the 737 MAX, 787-10 Dreamliner and 777x — are “on schedule.”

The manufacturer is in the process of putting the wings on the 737 MAX, a more fuel-efficient version of its best-selling aircraft, Jim Haas, director of product marketing at Boeing, told Middle East-based reporters on a visit to Boeing’s Everett production facility in Washington on Monday.

The single-aisle aircraft will be finished this year with flight tests to begin in 2016. First delivery will be in 2017 to the US airline Southwest, Haas said. Flydubai is also scheduled to receive its first 737 MAX in 2017.

“[The] performance and schedule [are] on track,” Haas said of the 737 MAX and the 777x, a newer version of its 777 model that will come into service in 2020. The 777x customers include Emirates, Eithad Airways and Qatar Airways.

Haas said the 787-10, slightly longer version than the airline’s 787-9 model that is already in service, is “marching along on schedule” with first flight scheduled for 2017 and delivery in 2018.

He added that he expects some customers will convert the existing 787-8 and 787-9 for the larger model.

Boeing has booked 146 orders for the 787-10, 492 for the 787-9 and 457 for the 787-8. Etihad Airways has ordered 71 of the -8 and -9 variants.