What happened

United Airlines Holdings (UAL -1.43%) is reportedly closing in on a massive order for new jets. Boeing (BA -1.83%), one of two companies that could benefit from the order, is flying high as a result, with shares up as much as 3% in Friday morning trading.

So what

Boeing shares by and large have been in a holding pattern for some time. The company was hit hard by the double blow of issues with its 737 MAX and then the pandemic, leading it to dramatically lever up its balance sheet, but it has slowly been making progress normalizing operations.

The question now is how long will that recovery take. Boeing hopes accelerating deliveries will help it to pay down much of the added debt it took on in 2020, but investors are worried that a global slowdown could cause airlines to shy away from new orders or defer deliveries.

But at least one airline, United, appears to be continuing with business as usual. According to Bloomberg, United is closing in on an order for more than 100 widebody jets, with Boeing's 787 Dreamliner and the Airbus (EADSY -0.05%) A350 being the prime contenders.

The deal, if announced, would be one of the largest-ever orders for widebody jets. And it would be a huge boost to either the Dreamliner or the A350 program. Longer-range jets have not been selling well in recent years, a trend that got worse as the pandemic brought international travel to a standstill.

Now what

United's willingness to go shopping is a boost for both Airbus and Boeing, and a win would certainly be a big shot in the arm for either company. But investors should be mindful that part of the reason United is interested in buying right now is that it is a buyer's market. Each plane maker could really use an order of this size. Both Boeing and Airbus are likely offering substantial discounts to list prices for the aircraft.

Airbus potentially has a leg up over Boeing because it could also possibly offer earlier deliveries of some of the smaller A321neo planes United ordered last year.

The bottom line is that although these headlines are good news for Boeing, even if the company wins the order, it is only one small step in a long and arduous rebuilding project. There's reason for excitement here, but investors should remain cautious about the stock.