Boeing’s troubled 737 Max has encountered a new software issue that could further delay its return to service, ABC News reports.

Citing anonymous sources, the Australian broadcaster said the issues surfaced during an audit meeting with regulators last weekend (11-12 January).

Boeing decided to not just rewrite the software for the MCAS flight control system, which is believed to have contributed to both Max crashes, but the entire flight computer software, ABC News said.

The new software intends to have the 737 Max’s two separate flight computers communicate with each other for the first time, the broadcaster added. In the past, one of the 737’s flight computers would operate independently and switch to the other during the next flight. During the audit last weekend, they found that the two flight computers were not talking to each other at start-up.

A CNN report, which followed up the ABC News report, said the issue is not related to the software revisions Boeing made to address the cause of two fatal crashes that killed 346 people, and would not occur during flight. The Max has been grounded since March 2019 following those crashes, which involved Ethiopian Airlines and Lion Air.

The computer issue was observed when booting up the computers on a Max and involves the so-called software power up monitoring function, which checks for anomalies when turning on the computers, CNN added. It is similar to the steps any computer might make when first turned on. CNN’s source said the process of turning on the computers is performed when the plane is on the ground, rather than in flight. The source added that the test was intended to find any issues like this one and that Boeing would fix the problem.

“We are making necessary updates and working with the FAA on submission of this change, and keeping our customers and suppliers informed. Our highest priority is ensuring the 737 MAX is safe and meets all regulatory requirements before it returns to service,” Boeing said in an emailed statement to Business Traveller Asia-Pacific.

Boeing’s new CEO David Calhoun, who joined the company on January 13, has said returning the 737 Max to service safely should be the company’s “primary focus” in 2020.