The NTSB criticized the FAA for a desultory response to the risk from faulty 737 rudders and Boeing for not fully informing airlines in advance about them.

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 U.S. NTSB said more than 40 foreign operators of Boeing 737 airplanes may be using planes with potentially faulty rudder control systems.