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 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 head of the Federal Aviation Administration told a U.S. House subcommittee Tuesday that safety culture improvements at Boeing may take three to five years to complete.

The U.S. National Transportation Safety Board (NTSB) has issued urgent safety recommendations regarding potential rudder control system issues in Boeing 737 airplanes. The concern follows incidents involving both U.

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,