Boeing's newest 737 model, the MAX, was grounded worldwide in March following two fatal crashes, one on Lion Air in Indonesia in October and another on Ethiopian Airlines in March, which together killed all 346 on board.
The 737 Max is a legacy of its past, built on decades-old systems, many that date back to the original version. The strategy, to keep updating the plane rather than starting from scratch, offered competitive advantages.
Chief Executive Officer Dennis Muilenburg said on Friday said the company now knows that a chain of events caused both disasters, with erroneous activation of so-called MCAS anti-stall software "a common link" between the two.
The Ethiopian-led investigation has begun piecing together details of flight 302, starting with faulty sensor data on take-off from Addis Ababa, questions over the Boeing 737 MAX's high speed and a nosedive coinciding with the software re-activation.