What happened

Boeing (BA -3.26%) has reportedly given up hope that the larger MAX 10 variant of its all-important 737 will be certified for commercial service before the end of 2022, a blow to the company's efforts to get the jets delivered to buyers. Shares of Boeing were trading down by more than 5% as of 1:52 p.m. ET Thursday on the report.

So what

The Boeing 737 MAX was once expected to be the top-selling plane in aviation history, but the model has so far failed to live up to expectations. A pair of fatal crashes led to a worldwide grounding of the aircraft between March 2019 and December 2020, as well as intense scrutiny into Boeing and the way it is regulated.

The MAX is flying again, but new regulations continue to weigh on Boeing's operations. Congress mandated that all new models and variants certified after the end of 2022 be subject to new cockpit alerting requirements, a costly and time-consuming rework for Boeing, as well as for the airline customers that will need to train pilots on those jets.

With the deadline approaching, Boeing has been racing to earn certification for its MAX 7 and MAX 10 variants. But at an event in India, Boeing marketing specialist John Dyson told Reuters that the company expects to get certification for the MAX 7 in time, but that regulatory approval for the MAX 10 will not occur until the first half of 2023.

Now what

Boeing has argued that although the 737 MAX variants differ in size, they are fundamentally the same plane and should fall under the same regulations. Airlines would certainly prefer it that way so they can save on training costs. Dyson said that Boeing is in talks with U.S. lawmakers about a possible extension to the deadline.

That argument is likely to be at least somewhat persuasive on Capitol Hill, and an extension that would allow the MAX 10 to be certified under the old rules is still possible. That would be good news for Boeing, which is looking to move as much metal as possible right now as it seeks to generate cash and pay down some of the billions in debt it took on during the pandemic.

But for now, what we have is uncertainty. For investors already worried about the potential for a recession that could eat into travel demand, and with it demand for new aircraft, the added bad news concerning the MAX 10 was enough to send the shares lower Thursday.