(CNN) — The National Transportation Safety Board issued a rare, urgent safety bulletin warning of potential problems with the jet engines on Boeing 737 Max aircraft.

Safety experts urged swift modifications to Boeing 737 Max engines, but the FAA and Boeing say they've issued warnings and are already working on a fix. Credit: robin - stock.adobe.com ...

Safety experts urged swift modifications to Boeing 737 Max engines, but the FAA and Boeing say they've issued warnings and are already working on a fix.