FILE PHOTO: Dennis Muilenburg, CEO, Boeing speaks during a roundtable discussion on defense issues with U.S. President Donald Trump at Luke Air Force Base, Arizona, U.S., October 19, 2018. REUTERS/Jonathan Ernst/File Photo

(Reuters) - Boeing Co said on Wednesday its chief executive, Dennis Muilenburg, had joined a test flight on a 737 MAX 7 jetliner for a demonstration of updated MCAS anti-stall software.

The software is at the center of investigations in the crash of Ethiopian Flight 302 last month and a Lion Air accident in Indonesia five months earlier. Both involved the slightly larger 737 MAX 8 model, which features the same cockpit.

During Wednesday’s test flight, the flight crew performed different scenarios to test failure conditions, Boeing said.

“The software update worked as designed, and the pilots landed safely at Boeing Field (near Seattle),” it said in a statement.

“Boeing will conduct additional test and demo flights as we continue to work to demonstrate that we have identified and appropriately addressed all certification requirements. We will submit the update for FAA (Federal Aviation Administration) review once that work has been completed in the coming weeks.”