Investigation Underway into Rare Dutch Roll Incident on Boeing 737 Max 8

Federal authorities and Boeing are investigating a rare and unsafe oscillation experienced by a Boeing 737 Max 8 during a recent Southwest Airlines flight. The flight, designated as Southwest 746, encountered a back-and-forth roll, known as a Dutch roll, on May 25. This motion, characterized by the nose of the aircraft tracing a figure-eight, is highly unusual and potentially dangerous.

According to a preliminary report by the Federal Aviation Administration (FAA), the aircraft experienced the Dutch roll before the crew regained control, allowing for a safe landing. While there were no injuries among the 175 passengers and six crew members, the aircraft sustained “substantial” damage. The FAA classified the incident as an “accident” and identified damage to the plane’s standby power control unit (PCU), which manages the rudder. It remains unclear whether the damaged PCU caused the roll or was a result of it.

Since the incident, the aircraft has only been flown to a Boeing facility in Washington state for further inspection. Boeing has not yet commented on the situation. Southwest Airlines has reported the incident to both the FAA and the National Transportation Safety Board (NTSB) and is cooperating with the investigation.

The NTSB has launched a formal investigation and has retrieved data from the flight data recorder to analyze the duration and severity of the Dutch roll. However, voice recordings from the cockpit were overwritten.

In February, the FAA mandated inspections of the rudder assembly on some 737 Max 8 aircraft due to concerns about loose or missing components that could impede rudder control. Authorities have not yet confirmed if this issue is related to the recent Dutch roll incident.

Dutch rolls are an uncommon and uncomfortable experience for both passengers and pilots. Kathleen Bangs, an aviation safety analyst and former airline pilot, explained that this movement involves excessive rolling and yawing, making the tail of the plane swing dramatically. While airline pilots are trained to handle such scenarios in simulators, the actual occurrence in flight is extremely rare.

Modern airliners, including the 737 Max 8, are designed to be inherently stable and equipped with yaw dampers to prevent such oscillations. In cases of a Dutch roll, pilots can counteract the movement by reducing speed and descending to thicker air, which typically stabilizes the aircraft.

Historically, Dutch rolls have led to serious incidents. In 1959, a Boeing 707 experienced a severe Dutch roll near Washington, D.C., resulting in the death of four out of eight occupants and the loss of three engines due to violent gyrations.

The investigation continues as authorities seek to determine the exact cause of the Dutch roll experienced by Southwest Airlines flight 746 and to ensure the safety of future flights.