The Boeing 737 Max has returned to the spotlight after a “Dutch roll” incident on a Southwest Airlines flight from Phoenix to Oakland in May caused significant structural damage, raising new safety concerns about the aircraft.
The National Transportation Safety Board (NTSB) is investigating the incident, which only recently came to light. The NTSB reported that the plane suffered damage to “structural components” but has yet to determine the extent or severity of the movements. Southwest Airlines is cooperating with the investigation but referred additional inquiries to the NTSB.
Although no injuries were reported, the Dutch roll incident adds to Boeing’s ongoing challenges. The Federal Aviation Administration (FAA) is auditing Boeing’s production lines following a separate issue in January when a door plug blew off a 737 Max 9 operated by Alaska Airlines. Boeing is currently restricted from increasing production beyond 38 planes per month until regulatory approval is obtained.
Understanding Dutch Roll
A Dutch roll is a series of out-of-phase oscillations where the aircraft simultaneously rolls in one direction and yaws (twists) in the opposite direction. Daniel Kwasi Adjekum, an assistant professor in the aviation department at the University of North Dakota, explained that this motion resembles “the rhythmical flowing motion of a Dutch skater on a frozen canal,” as described by Michael Cook in “Flight Dynamics Principles.”
Dutch rolls can be induced by factors such as wind or pilot commands, according to Boeing. While these movements are not uncommon and can be part of acrobatic displays at air shows, they are rare in commercial flights due to the presence of yaw dampers that correct unexpected movements.
What Passengers Should Know
Dutch rolls are generally not dangerous but can be uncomfortable, potentially causing nausea or airsickness. Pilots are trained to manage Dutch rolls and restore normal flight conditions.
“My only advice for passengers is always to be strapped in with their seat belts when seated to ensure their safety in case of such events,” advised Adjekum.
John Cox, a former airline pilot and CEO of Safety Operating Systems, noted that damage from Dutch rolls, like that seen in the Southwest incident, is unusual. He expressed that there are “more questions than answers” regarding the specifics of this event.
The incident occurred on Southwest flight 746 from Phoenix to Oakland while cruising at 34,000 feet around 8 a.m. on May 25, according to the NTSB.
Conclusion
While Dutch rolls are not inherently dangerous and pilots are well-equipped to handle them, the recent incident on a Southwest Airlines flight has brought renewed attention to the safety of the Boeing 737 Max. Passengers are advised to keep their seat belts fastened while seated to ensure safety during unexpected events.