FAA investigates ‘Dutch roll’ on Southwest Airlines 737 Max plane [Video]

WASHINGTON — A Boeing 737 Max suffered damage to parts of the plane’s structure after it went into a “Dutch roll” during a Southwest Airlines flight last month, U.S. investigators said Friday.

The NTSB comment suggests the incident was more serious than previously known.

“Following the event, SWA performed maintenance on the airplane and discovered damage to structural components,” the safety board said.

A Dutch roll is an unstable and potentially dangerous combination of yaw, or the tail sliding sideways, and the plane rocking from side to side. The motion repeats, usually several times.

Pilots train to recover from a Dutch roll, and most modern planes include a device called a yaw damper that can correct the situation by adjusting the plane’s rudder. A preliminary report by the Federal Aviation Administrationsaid that after the Southwest plane landed, damage was discovered to a unit …