US regulators say Boeing withheld 'concerning' internal messages on 737 MAX. With planes grounded, Boeing's Board in Emergency Meetings to deal with the crisis.

Boeing's board of directors and top staff from its commercial airplanes division were due to meet in Texas on Sunday and Monday after a 2016 exchange was released which suggested the company had known about problems with the flight control system years before it became implicated in two fatal crashes.

In the messages, which were between two lead technical pilots on the Boeing 737 Max Program, one complained the system was "running rampant" and difficult to control. "Granted, I suck at flying, but even this was egregious," he said.

Boeing's 737 MAX jets have been grounded since March. It has been racing to find a fix to the problem, although has said the jets may not return to service until next year.