By Naveen Athrappully Contributing Writer The National Transportation Safety Board issued urgent safety recommendations to aircraft manufacturer Boeing and the Federal Aviation Administration regarding a “significantly compromised” critical flight control

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.

At least forty foreign air carriers could be flying Boeing 737 jets with a rudder control system that has the potential to jam, according to the Chair of the U.S. National Transportation Safety Board.

Last month, the US National Transportation Safety Board stated that more than 40 foreign operators of Boeing 737 airplanes may be using 737 or 737 Next Generation planes with rudder components that could pose safety risks.

The National Transportation Safety Board Thursday issued urgent safety recommendations to The Boeing Company and the Federal Aviation Administration in response to the potential for a jammed or restricted rudder control system on some 737 airplanes.

The FAA is not moving quickly enough to address risks posed by non-conforming parts on hundreds of 737s, NTSB Chair Jennifer Homendy said in a Sept. 30 letter to the agency's top official.

The Federal Aviation Administration issued a notice to Boeing 737 Next Generation and Max operators about a potential issue with its rudder control system. The National Transportation Safety Board previously issued its own urgent safety recommendation,

The regulator said operators of the Boeing 737 NG and 737 MAX airplanes with SVO-730 rudder rollout guidance actuators should give specific instructions to flight crews.

The US Federal Aviation Administration warned operators of certain Boeing Co. 737 aircraft that the rudder system could possibly jam due to a faulty part, a week after a safety official rebuked the agency for not acting sooner to address the issue.

The U.S. Federal Aviation Administration (FAA) on Tuesday issued a safety alert informing operators of the potential for limited or jammed rudder movement on certain Boeing (NYSE:BA) 737 airplanes. The FAA issued a so-called Safety Alert for Operators (SAFO).