Boeing's 737 Max could stay on the ground until late this year after a new problem emerged with the plane's in-flight control chip.

This latest holdup in the plane's troubled recertification process has to do with a chip failure that can cause uncommanded movement of a panel on the aircraft's tail, pointing the plane's nose downward, a Boeing official said. Subsequent emergency tests to fix the issue showed it took pilots longer than expected to solve the problem, according to The Wall Street Journal.

This marks a new problem with the plane unrelated to the issues Boeing is already facing with the plane's MCAS automated flight control system, an issue the company maintains can be remedied by a software fix. Boeing hopes to submit all of its fixes to the Federal Aviation Administration this fall, the Boeing official said.

"We're expecting a September time frame for a full software package to fix both MCAS and this new issue," the official said. "We believe additional items will be remedied by a software fix."

Once that software package is submitted, it will likely take at least another two months before the planes are flying again. The FAA will need time to recertify the planes. Boeing will need to reach agreement with airlines and pilots unions on how much extra training pilots will need. And the airlines will need some time to complete necessary maintenance checks.

FAA spokesman Lynn Lunsford declined to comment on a specific timeline for the plane's recertification, saying, "We have steadfastly stayed away from offering any timelines."

The global Max fleet was grounded in mid-March following two fatal crashes, in which a malfunction of MCAS was implicated. The crashes killed 346 people combined.