FILE - A worker wearing a mask walks past a Boeing 737 Max 9 as it is prepared for a flight from Renton Municipal Airport, Nov. 18, 2020, in Renton, Wash. (AP Photo/Ted S. Warren, File) Safety experts ...

FILE - A worker wearing a mask walks past a Boeing 737 Max 9 as it is prepared for a flight from Renton Municipal Airport, Nov. 18, 2020, in Renton, Wash. (AP Photo ...

WASHINGTON — Safety experts recommended Wednesday that the engines on Boeing's troubled 737 Max airplanes be modified quickly to prevent smoke from filling the cockpit or cabin after a safety feature ...