Phoenix, Arizona – Federal authorities are currently investigating an in-flight oscillation event that occurred on a Boeing 737 Max 8 aircraft during a recent Southwest Airlines flight. The incident, known as a Dutch roll, occurred during a flight from Phoenix to Oakland, California with 175 passengers and six crew members on board. Luckily, no injuries were reported as a result of the event.
Boeing, the manufacturer of the aircraft, has come under increased scrutiny following a series of recent incidents involving its planes. Most notably, a door plug blowout during an Alaska Airlines flight in January, as well as a disclosed quality issue with 787 Dreamliner jets. Additionally, the FAA is probing the use of titanium with falsified documentation in some Boeing and Airbus planes.
The Dutch roll incident on the Southwest flight occurred on May 25 at 34,000 feet. A Dutch roll is characterized by a rolling motion of the aircraft, accompanied by side-to-side movement of the tail, also known as yawing. While this motion is usually not dangerous, it can be uncomfortable for passengers, according to aviation experts.
Boeing explains that Dutch rolls are typically caused by wind or pilot input, resulting in a series of oscillations that will either correct themselves or require pilot intervention to stabilize the aircraft. Pilots are trained to recognize and mitigate Dutch rolls, while aircraft are equipped with yaw dampers to automatically address such motions.
In the case of the Southwest flight, the flight crew managed to regain control of the aircraft following the incident. Subsequent maintenance revealed damage to certain structural components, including the standby power control unit. Retired airline pilot John Cox expressed surprise at the incident, noting that while Dutch rolls are not uncommon, damage resulting from one on a Boeing 737 is unheard of.
Investigations are ongoing to determine whether the damaged power control unit contributed to the event or if the event caused the damage. Southwest Airlines reported the incident and damage to the NTSB on June 7, with data from the flight data recorder being analyzed to understand the extent of the event. A preliminary report from the NTSB is expected to be released within 30 days of the incident on May 25.
Southwest Airlines has pledged its full cooperation with the investigation, while Boeing has deferred questions to the airline. The event was not widely publicized until a recent article from the Aviation Herald, a site that covers industry incidents and news, shed light on the incident.