Replaced Two Malfunctioning Units In The Weeks Prior To Lion Air Accident

Southwest Airlines replaced two malfunctioning flight-control sensors on Boeing 737 MAX airplanes in the weeks prior to the Lion Air Flight 610 accident in October.

The Wall Street Journal reports that, according to maintenance records obtained by the paper, the sensors were the same type as the devices that are the focus of the accident. The maintenance summary documents indicate that both discrepancies involved 737 MAX 8 airplanes, the same type as the aircraft that went down in the ocean off the coast of Indonesia resulting in the fatal injury of all 189 people on board.

The document shows that the sensors, or related hardware, needed to be replaced. It further indicates that pilots reported that they were unable to engage autothrottle settings on the airplanes.

A spokeswoman for Southwest said that the sensors did not fail but were replaced as a precautionary measure as part of a troubleshooting process. At least one was repaired, she said.

But the spokeswoman also said that the Southwest airplanes did not experience a situation similar to the issue described in Boeing's service bulletin, which warned of the potential for incorrect angle-of-attack data to be transmitted from the sensors to flight-control computers.

The Southwest incidents did not lead to the declaration of an emergency on either flight. One was noted on October 9th in Baltimore, and the other was written up in Houston on October 21, according to the documents.

The Wall Street Journal reports that neither Boeing or the FAA had any immediate comments on the Southwest maintenance documents.

(Image from file)

FMI www.wsj.com, www.boeing.com, www.southwest.com