Southwest Airlines flight ‘dutch roll’ probed by US regulators

Federal aviation safety officials are investigating a Southwest Airlines Co. flight that experienced an unusual rolling that may be linked to a damaged backup power control unit.

The Boeing Co. 737 Max 8 aircraft landed safely and there were no injuries among the 181 people on the flight between Phoenix and Oakland, according to information from the Federal Aviation Administration. The agency is looking into the May 25 incident along with the National Transportation Safety Board.

The plane experienced what is known as a “Dutch roll” before pilots regained control, the FAA said in a statement. Such movement involves tail “wagging” and rocking from side to side, and is named after the motion of a Dutch skating technique. The inspection after the flight revealed damage to a standby power unit.

“Other airlines have not reported similar issues,” the FAA said.

Southwest said it’s working with both agencies on the investigation, and the NTSB said it expects to issue a preliminary report within 30 days.