The Federal Aviation Administration has launched an investigation after a Southwest Airlines Boeing 737 Max plane experienced a "Dutch roll" motion on a May 25 flight from Phoenix to Oakland, causing "substantial" damage to the aircraft.
Documentation on Boeing’s website describes a Dutch roll as when the nose of the plane "may go left to right as the airplane simultaneously banks side to side." The maneuver is caused by "wind or pilot input."
A preliminary FAA incident report says the Southwest Airlines plane "experienced a Dutch roll, regained control and post flight inspection revealed damage to the standby PCU [power control unit]."
There were 175 passengers and six crew members onboard the Boeing jet when the incident happened. The National Transportation Safety Board (NTSB), is also investigating, according to The Associated Press.
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The FAA and Southwest Airlines did not immediately respond Friday to a request for comment from FOX Business.
Boeing says on its website that "Ice skaters use the outer edge of their skates to propel themselves across the ice, rocking from side to side while also moving to the left, then to the right and back again."
"Airplanes can make similar lateral and directional motions in flight, rolling and yawing much like a traditional Dutch ice skater rhythmically swaying down one of Amsterdam’s frozen canals," it adds.
"Just as skaters avoid swaying too far and losing their balance, airplanes are designed to keep roll and yaw within regulatory requirements to ensure safety -- and potentially reduce the risk of airsickness," Boeing also said.
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The Southwest Airlines incident comes as Boeing is investigating whether some fasteners on its undelivered 787 Dreamliner planes have been incorrectly installed, the aircraft maker told FOX Business on Friday.
A Boeing spokesperson said "Our 787 team is checking fasteners in the side-of-body area of some undelivered 787 Dreamliner airplanes to ensure they meet our engineering specifications."
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"The in-service fleet can continue to safely operate," the spokesperson added, noting that the issue was discovered during its regular quality control checks. "We are taking the time necessary to ensure all airplanes meet our delivery standards prior to delivery. We are working closely with our customers and the FAA and keeping them updated."
