The head of the National Transportation Safety Board says the Federal Aviation Administration needs to up the urgency on the potential for jammed flight controls on some Boeing 737s.

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.

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.

NTSB chair Jennifer Homendy accused the FAA of "downplaying the urgency" of potentially defective rudder systems on some Boeing 737 Max jets.