Just two years ago, Boeing (BA -0.76%) was building 14 787 Dreamliner jets per month: a record pace for a wide-body jet. However, the COVID-19 pandemic crushed demand, forcing the aerospace giant to slash output to just five per month.

At a recent conference, CEO Dave Calhoun suggested that Boeing will eventually return to its pre-pandemic Dreamliner production rate. This prediction is unlikely to come true, though, as long-haul travel will recover slowly from the pandemic and narrow-body jets are poised to serve a growing proportion of long-haul demand.

Planning for an incredible production recovery

Before the pandemic, 787 Dreamliner production was split evenly between factories in Everett, Washington, and North Charleston, South Carolina. Because of the sharp drop in production, Boeing decided to stop building the 787 in Everett. As of March, it has moved all final assembly to its North Charleston facility.

Many investors wondered what this move meant for future production plans. After all, the North Charleston plant built just seven 787s per month at its peak. At a recent conference hosted by Bernstein Research, Calhoun said that Boeing would get Dreamliner production back to previous rates even with only one final assembly plant.

A rear view of a Boeing 787-10 landing.

Image source: Boeing.

The Boeing CEO did caution that it will take years to get there. However, he emphasized that -- with careful planning -- the South Carolina factory has enough space to accommodate production of 14 Dreamliners per month in the future.

Replacement demand won't cut it

Factory space won't be Boeing's biggest problem in getting back to a 14-per-month Dreamliner production rate. Demand simply won't support that level of output anytime in the next decade.

For one thing, Boeing can't rely on replacement demand to drive a rebound in 787 production. Between 1995 and 2011, Boeing delivered fewer than 1,600 passenger wide-body jets: an average of about 93 per year. (These production years roughly correspond to the wide-bodies due for retirement over the next 15 years.)

Even if Boeing doesn't lose any of this wide-body replacement business to Airbus, it would only support production of about five 787s per month on average. (This assumes that the 777X would capture up to a third of Boeing's replacement volume.) Thus, getting back to a production rate of 14 per month -- or anywhere close -- requires airlines to purchase a lot of wide-body jets for growth.

Slower long-haul growth

A few years ago, airlines used most of their new 787s to grow on long-haul routes. This included a lot of unsustainable growth. For example, Norwegian Air built up a fleet of more than three dozen Dreamliners over the past decade. It never made a profit on long-haul flights and recently got rid of all of its 787s. Many other Dreamliner customers have scaled back their long-haul growth ambitions.

A Boeing 787 Dreamliner in the Norwegian Air livery.

Image source: Boeing.

This retrenchment began before the pandemic hit. As a result, by January 2020, Boeing had announced two Dreamliner production cuts, which would have reduced output from 14 per month to 10 per month by early 2021. Of course, the pandemic forced even deeper cuts.

Long-haul travel will eventually return to growth and should surpass pre-pandemic levels within three years or so. Nevertheless, it will grow at a slower pace than the pace of a few years ago, as airlines place more emphasis on profitability rather than growth. The top global airline industry trade group estimates that the pandemic permanently wiped out two years of industry growth.

Narrow-body jets will gain share

Lastly, the Airbus A321XLR -- and a potential new Boeing jet -- will cannibalize both growth and replacement demand for wide-bodies like the 787 over the next decade. The A321XLR will be able to serve a huge swath of markets that were only viable with wide-bodies previously, but with much lower trip costs.

A number of global airlines like American Airlines and United Airlines have placed big orders for the A321XLR. Many of those jets will replace Boeing 757 narrow-bodies used on longer routes, but some will replace small wide-bodies like the 767. Others could open up new routes. Either way, the A321XLR will steal sales from next-generation small wide-bodies like the 787 Dreamliner.

In short, the replacement market can only support today's depressed level of 787 production. And with airlines likely to grow their wide-body fleets at a modest pace over the next decade, that leaves Boeing virtually no chance of sustaining a 14-per-month 787 production rate anytime in the coming decade.