Alva Review-Courier -

Aviation regulators worldwide laid down a stark challenge for Boeing to prove that its grounded 737 Max jets are safe to fly amid suspicions that faulty software might have contributed to two crashes that killed 346 people in less than six months.

In a key step toward unearthing the cause of the Ethiopian Airlines crash, flight recorders from the shattered plane arrived Thursday in France for analysis, although the agency in charge of the review said it was unclear whether the data could be retrieved. The decision to send the recorders to France was seen as a rebuke to the United States, which...