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

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 National Transportation Safety Board followed its urgent safety alert last week about a potential Boeing 737 rudder failure by criticizing the Federal Aviation Administration for a desultory response to the risk and Boeing for not fully informing airlines in advance about the system that failed.