The head of the National Transportation Safety Board blasted the Federal Aviation Administration, saying the agency is not taking seriously enough the potential for jammed flight controls on some Boeing 737s.

The National Transportation Safety Board issued urgent safety recommendations to Boeing over a steering defect related to its 737 planes, adding its growing list of woes.

The head of the US National Transportation Safety Board criticized US aviation regulators for “downplaying the urgency” of addressing a possible rudder malfunction on some Boeing Co. 737 aircraft in an unusually public rebuke.

Some Boeing 737s could have a rudder system malfunction, according to the National Transportation Safety Board. What the NTSB called "Urgent Safety Recommendations" apply to some of Boeing’s B-737NG and 737MAX planes,