FAA investigates Boeing 737 Max “Dutch Roll” incident

A federal investigation is currently underway to determine how a Southwest Airlines passenger plane suffered significant damage when it experienced a rare phenomenon called a “Dutch roll” at an altitude of nearly 38,000 feet.

Flight N8825Q, a Boeing 737 Max carrying 175 passengers and six crew members, was en route from Phoenix to Oakland on May 25 when its tail began yawing, or weaving, left and right while the plane’s wings swayed from side to side.

“Dutch Roll” is the name given to this potentially dangerous, asymmetrical sideways movement, which is said to be inspired by the movements of ice skaters.

The Federal Aviation Administration said in a statement on Thursday stated that it is working with Boeing and the National Transportation Safety Board to investigate the cause of the error.

Boeing declined to comment.

A preliminary FAA report said the aircraft “performed a Dutch roll, regained control, and post-flight inspection revealed damage to the standby PCU,” meaning the power control unit.

The plane was able to land safely in Oakland and no injuries were reported.

U.S. aviation regulations state that a Dutch roll performed below the permissible speed “must be positively dampened with free control and must be controllable with normal use of the primary controls without requiring extraordinary skill on the part of the pilot.”

In most cases, an aircraft’s yaw damper is designed to correct lateral movement.

Boeing is under multiple investigations, including by the Justice Department, after a control panel on a 737 Max 9 aircraft burst in January. The incident prompted investigators, after receiving evidence from whistleblowers, to launch investigations into other Boeing aircraft, including the 787 Dreamliner.

The company says it has invested heavily in security measures, including the use of machine learning algorithms to detect potential errors.