Updated Dec. 16, 2019.

Boeing is going to suspend production of its 737 Max jet starting in January. In a statement, the aircraft manufacturer says reducing output will allow it to concentrate on delivering the approximately 400 aircraft it has built and parked, once the plane is cleared to fly again.

The 737 Max been grounded since March, after fatal crashes in Indonesia and Ethiopia killed 346 people. The plane’s flight control software has been implicated as the cause, and Boeing is working on a fix. That has to be approved by regulators, and a date for the plane’s return to service keeps being pushed back.  

Marketplace has a few questions and answers: 

Q: Has Boeing been building 737 Max planes this whole time?

Yes, the company has been building planes at its Renton, Washington, plant, even while they have been grounded, as we witnessed in March. In April, Boeing did slow production slightly from 52 planes per month to 42. Because it can’t deliver those planes to customers, it’s been parking them in Renton and other Boeing facilities. 

Continuing to build the planes was, in part, a demonstration from Boeing that it was confident that the aircraft could be fixed easily, said Kevin Michaels, managing director at consultants AeroDynamic Advisory.

“They were indicating they were anticipating a timely resolution,” he said. 

Q: What does slowing or halting production mean for Boeing and its employees? 

The planes are Boeing’s cash cow. The single-aisle 737 has been a backbone of many fleets since it started service in 1968. The Max is the fourth generation of the plane, designed to be more fuel efficient, with new engines. Boeing has orders for more than 4,600 of them, but right now it can’t deliver them. Continuing production has allowed it to continue to employ workers and buy parts from suppliers. 

The impact of slowing or halting production will depend on how long that lasts. Boeing employs 12,000 people at its 737 factory. The plant closes for the Christmas and New Year holidays, and Boeing could redeploy many workers. It could also continue to buy and stockpile parts from its suppliers to minimize the impact to them. 

Q: What does slowing or halting production mean for airlines and passengers?

Boeing delivered fewer than 400 of the 737 Max jets globally before the grounding, and airlines have been coping without them since March. They are already operating their contingency plans, so the impact on passengers will likely be low. 

In the United States, American, Southwest and United airlines had already taken delivery of 737 Max planes before they were grounded. American says it doesn’t anticipate the Max will return to service until April 2020 and has already made necessary schedule changes. 

Q: When is the 737 Max likely to fly again?

The Federal Aviation Administration and other flight regulators around the world are being rigorous about the recertification of the planes after facing criticism of being too close to Boeing during the initial process.  

Even once the plane is approved for flights and Boeing starts delivering the backlog of planes, it could take a while for airlines to reintroduce it to their fleets.

“Even once they ship, all these airlines are going to have to start training their pilots,” said Dawna Rhoades, professor at Embry-Riddle Aeronautical University. She said word is coming out that a lot more training on how the Max handles versus its predecessors is going to be required, and that will mean airlines need simulators updated to reflect any software fixes. 

The airline’s ability to enter the aircraft into service will dictate how fast they can get them flying, said Michaels of AeroDynamic Advisory. “For a lot of airlines, it’s difficult to bring more than a couple per month into your fleet,” he said.