US authorities are investigating an unusual movement of a Boeing plane mid-flight

The so-called “Dutch roll,” the name given to the combination of motion when the tail slides and the plane swings from side to side — a motion that supposedly mimics a Dutch ice skater — occurred on a May 25 flight from Phoenix, Arizona, to Oakland. , California.

According to the Federal Aviation Administration, quoted by the BBC, the plane regained control and no one on board was injured, but the plane sustained “significant” damage. A post-flight inspection of the two-year-old plane revealed major damage to the power control unit, which controls the rudder.

There were 175 passengers and six crew members on board, according to the airline.

According to CNN, the “Dutch roll” is unusual: Most passengers have never felt the plane make this motion.

Instead of returning to commercial service, Southwest Airlines' 737 MAX headed from Oakland to Boeing's facility in Everett. The plane had been in Everett since the late evening of June 6.

Boeing has been under criticism since the 737 Max lost its emergency exit door shortly after takeoff from Portland on January 5, while flying with 117 people on board at an altitude of about 4,876 metres. According to the preliminary report issued by the US agency responsible for transportation safety (NTSB), the plane lost four screws.