News services and Herald staff

A new computer problem has been found in the troubled Boeing 737 Max that will further delay the plane’s return to flying after two deadly crashes, according to two people familiar with the matter.

The latest flaw in the plane’s computer system was discovered by Federal Aviation Administration pilots who were testing an update to critical software in a flight simulator last week at a Boeing facility near Seattle, the people said.

In an emailed statement Wednesday, the FAA confirmed a problem was found but did elaborate. “The FAA recently found a potential risk that Boeing must mitigate,” the agency said.

“The safety of our airplanes is Boeing’s highest priority,” said Boeing spokesman Gordon Johndroe. “We are working closely with the FAA to safely return the Max to service.”

One of the people familiar with the discovery said it would add one to three months to the timetable for returning the Max to flight. Both spoke on condition of anonymity.

The plane was grounded worldwide in March after a system called the Maneuvering Characteristics Augmentation System (MCAS) was linked to two fatal accidents since October that killed 346 people. Boeing has been working on a fix, which the FAA was examining.

But last week the FAA discovered that a failure of a microprocessor on the jet could cause the plane to dive in a way that pilots had difficulty recovering from in simulator tests, according to a person familiar with the finding who asked not to be named.

While the issue reportedly doesn’t involve MCAS, it could produce an uncommanded dive similar to what occurred in the crashes, according to one person.

“The FAA will lift the aircraft’s prohibition order when we deem it is safe to do so,” the FAA said in the emailed statement.

From reports by The Associated Press and Bloomberg News.