SEATTLE/PARIS, March 4 (Reuters) – Boeing Co has preliminary plans to boost production of its cash cow 737-family narrowbody to around 47 per month by the end of next year, as the U.S. planemaker looks to extend its recovery from successive crises, two people familiar with the matter said.

After slashing production due mainly to the pandemic, Boeing and European rival Airbus SE are seeing more demand for their medium-haul passenger jets, with both planemakers adding eye-catching deals to their order books in recent weeks.

Boeing’s production plans shift and are influenced by many factors, the people cautioned. Doubts are already swirling in the industry over whether the supply chain will be able to meet aggressive production ramp-up plans, particularly in Europe. Suppliers are grappling with labor and materials shortages and weakened balance sheets following the overlapping pandemic and 737 MAX safety grounding crises.

Boeing said in late January it was working to clear an inventory of 335 737 MAX airplanes amassed following two fatal crashes of the jet that grounded the plane for 20 months. It has estimated most of those jets would be delivered by the end of 2023.

Boeing declined to comment on its production plans and referred to its last public statements.

In late January, Chief Financial Officer Brian West said the 737 program was producing at a rate of 27 jets per month and was on track to reach 31 per month “fairly soon”.

Two of the people said the 31-jet monthly stride would come during the second half of the year, though a third person said it could happen sooner.

Beyond that, Boeing aims to increase to around 38 narrowbody jets monthly during the first half of 2023, and reach about 47 jets per month in the second half of 2023, two people said.

Boeing was laying the groundwork to nearly double production by the end of 2023, the third person said, but noted the plans could change due to supply chain constraints or other factors.

A rate of 47 aircraft per month is five shy of its build rate in 2019, when the 737 MAX was grounded.

Airbus, meanwhile, has set a production target of 65 a month by summer 2023 for its A320-family narrowbody.

It has been at odds with engine makers led by France’s Safran over its ambitions to push production afterwards as high as 75 a month.