Boeing said Friday it discovered a new flaw in the software on the grounded 737 MAX aircraft, but hopes to resolve the matter shortly so that it does not further delay the plane's expected return to service. "We are making necessary updates and working with the FAA on submission of this change and keeping our customers and suppliers informed," the company said a statement, referring to the US Federal Aviation Administration.

"Our highest priority is ensuring the 737 MAX is safe and meets all regulatory requirements before it returns to service." The statement did not elaborate on the nature of the problem. According to a person with knowledge of the matter, the glitch causes other onboard software to malfunction during startup.

Boeing uncovered the new problem during a "technical review" last week, the person said, calling the problem "minor" and adding that it should not delay the plane's return to service.

Boeing and the FAA are currently reviewing fixes to the aircraft's MCAS anti-stall flight system, which was implicated in the crashes of Lion Air and Ethiopian Air flights that together left 346 people dead. The MAX has been grounded worldwide since March 13, 2019. Before the planes can return to service, civil aviation authorities must also determine what training MAX pilots will require and schedule a test flight.