More than 300 Boeing 737 MAX 8 and MAX 9 passenger jets around the world have been taken out of service following two fatal crashes over the past five months in Ethiopia and Indonesia that killed almost 350 people combined.

The causes of both crashes are still under investigation. One of the biggest unanswered questions: Was the plane’s software to blame?

What we know

• Satellite data gathered from the Ethiopian Airlines flight and evidence from the crash site showed similarities with the accident in Indonesia, which prompted the US Federal Aviation Administration to ground all Boeing MAX jets in service.
• Technical analysis of the black boxes from the crashed Ethiopian Airlines jet is set for Friday in France. It will take several days to complete the first readings from the boxes, French aviation officials said. The US National Transportation Safety Board is sending investigators to assist.
• Following the Lion Air crash in Indonesia in October, Boeing said it was preparing a software upgrade for the jets. After the Ethiopia crash, the company said it would deploy that upgrade across the fleet “in the coming weeks".
• Boeing maintains its new, fuel-efficient jets are safe, but supported the FAA decision to ground them. Fearing a financial hit and brand damage, investors have wiped about US$26 billion off the company’s market value.
• US lawmakers said the planes could be grounded for “weeks” to upgrade the software and install it in every plane.

What’s next?

• Investigators are expected to release a preliminary report based on information they glean from the data and cockpit recordings captured by the two black boxes.
• A decision will be made by countries about whether and when to lift the grounding of the Boeing jets based on that information.

- Reuters