Federal investigator and Boeing officials are looking into a May Southwest Airlines flight from Phoenix to Oakland when the plane made an unexpected “Dutch roll” where the plane seems to slide side-to-side midflight, an aviation move known as yawing, the Washington Post reports.
The maneuver is rarely dangerous to a commercial airline flight or the passengers in the plane, although the unexpected move can cause some discomfort and panic. The Southwest pilots were able to quickly regain control of the aircraft after it experienced a few rolls.
The May flight may have experienced heavy winds causing the plane to experience turbulence, but investigators are looking into the possibility that a software glitch caused the plane’s control systems to malfunction. Aviation engineers note that the 737 Max-8 is equipped with automatic yaw dampeners, devices that could cause yawing if malfunctioning.