DALLAS (AP) — Boeing says it will be several weeks before it fully resumes building passenger planes, as factory workers return following a strike that lasted nearly two months.

A Boeing spokesperson said Tuesday that the delay in restarting plants in Washington state and Oregon is due to multiple steps needed to resume production.

Airline customers have grown increasingly upset over delays in getting new planes from Boeing — delays that started long before 33,000 machinists went on strike Sept. 13. Boeing's schedule for gaining certification of new 737 Max models has also been pushed back.

Irish airline Ryanair still expects to get its first 737 Max 10s in the first half of 2027, but the CEO of American Airlines declined to predict Tuesday when his airline might see the largest version of the Max, which has not yet been certified by U.S. regulators.

“I can't go run Boeing — it's not my expertise, it's not where I come from,” Robert Isom said. “Let's just get one quality aircraft off the line first."

After that, Boeing can worry about ramping up production of the Max and meeting airline delivery schedules, Isom told reporters outside an airline conference in Dallas.

Boeing workers represented by the International Association of Machinists and Aerospace They faced a deadline of Tuesday to return to work after voting last week to accept a Boeing contract offer that will raise pay rates 38% over four years but won't restore pensions that were frozen a decade ago.

The strike shut down production of the 737 Max and 777 passenger planes and a cargo-carrying version of the 767 plane. Boeing continued building 787s, which are produced by nonunion workers in South Carolina.

The strike cut deeply into the cash that Boeing receives when it delivers new planes.

Boeing said Tuesday that it delivered 14 planes in October including planes that were finished before the strike began. Boeing said it took orders for 63 planes, including 40 737 Max jets by leasing company Avia Solutions Group.