PR groundwork laid for Boeing 737 Max return

US airlines using the Boeing 737 Max aircraft will conduct demonstration flights with company officials on board as part of an effort to convince customers the plane is safe.

American, United and Southwest airlines will make the flights as part of a public-relations campaign to rebuild confidence in the Max after crashes in Indonesia and Ethiopia killed 346 passengers and crew. The airlines haven't yet set a date for the flights.

The flights are a variation on a theme struck by Boeing CEO Dennis Muilenburg and the Federal Aviation Administration, or FAA, Administrator Stephen Dickson. Muilenburg said the company has conducted 500 test flights. He was on board for at least two and said other Boeing employees were "eager to do the same".