Boeing Co. hopes to deliver 737 MAX aircraft to airlines before the end of the year even if regulators haven't approved related pilot training, people familiar with the matter said.

As the plane maker prepares for the Federal Aviation Administration to lift a MAX flight ban as soon as December, Boeing is discussing with regulators whether it can deliver the aircraft before airline pilots have undergone required training needed to fly the jet, these people said. The emerging plan comes amid increasing signs there will be lag between an FAA's lifting of a flight ban and its approval of new training for pilots.

Delivering aircraft before all the regulatory approvals are complete would relieve pressure on the manufacturer as it contemplates further cutting or halting MAX production amid the protracted grounding. It would also help airlines that have lost hundreds of millions of dollars and disrupted passengers' travel plans. Under the plan, airlines still wouldn't fly the plane with passengers until the training occurs.

"Subject to strict regulatory approval, we continue to complete key milestones that put us on a path to certification of the MAX in December, with training approved in January, paving the way for the safe return of the MAX to commercial service," a Boeing spokesman said.

The FAA's order is expected as soon as mid-December, barring any further engineering and testing delays that have kept the MAX fleet grounded since a second 737 MAX crashed in Ethiopia in March, the people familiar with the matter said. That crash followed another accident in Indonesia less than five months earlier; in all, 346 people died.

Last week, Boeing cleared a key hurdle following a series of certification simulator tests with the FAA, a person familiar with the process said.

But related pilot training isn't expected to be formally approved until a number of weeks after the FAA certifies the MAX as safe for flight, following a public comment period, the people said. That would effectively prevent airlines from carrying passengers until January at the earliest under the current expected timing.

Airlines have been anxious for Boeing to resume deliveries of the MAX and want to avoid bottlenecks and long waits once the plane is cleared for service.

Southwest Airlines Co. and American Airlines Group Inc. said last week they were taking the MAX out of their schedules through early March, longer than previously signaled. Carriers have a series of steps to prepare their aircraft to carry passengers. Not only do they need to take them out of storage, but they are also planning their own demonstration flights and public-relations campaigns.

Southwest and American want to train all their 737 pilots before adding the MAX back into schedules to avoid scheduling issues that could arise if only some pilots are able to operate the plane.

Since the spring, both FAA and Boeing officials sketched out a process that envisioned MAX deliveries resuming roughly simultaneously with completion of pilot-training efforts. Those earlier scenarios didn't take into account additional weeks needed for regulators to complete training requirements and for airlines to implement those changes.

As the end of the year approaches, Boeing is running low on parking spots for the 737 MAX as finished planes pile up at locations in the Puget Sound area. Boeing has been producing the 737 at a rate of 42 planes a month at its Renton, Wash., factory since the aircraft's grounding, down from a previous monthly rate of 52. The manufacturer has stored planes at airfields in the Pacific Northwest and even put some in employee parking spaces.

While Boeing has about two months' of parking spots available, the plane maker is identifying other storage space if needed, the person familiar with the process said.

Boeing Chairman Dave Calhoun has said the FAA's ungrounding order would start a longer process to fully return the MAX to service around the world, an effort expected to last into early 2021.