An investigation has been launched into a Boeing-manufactured United Airlines plane that experienced a rudder pedal malfunction during a landing rollout last month. The incident occurred on Flight 1539, which had flown from Nassau, Bahamas, and was landing at Newark Liberty International Airport in New Jersey on February 6th.

According to a preliminary report released by the National Transportation Safety Board (NTSB) on Thursday, the captain of the Boeing 737-8 aircraft reported that the rudder pedals did not respond to foot pressure while attempting to maintain the runway centerline during the landing rollout. The pedals were described as being "stuck" in their neutral position.

To navigate the situation, the captain utilized the nose wheel steering tiller to keep the airplane near the runway centerline while slowing down to a safe taxi speed. The issue with the rudder pedals was also reported by the first officer during a high-speed turnoff. Interestingly, shortly after, the rudder pedals began to function normally again.

Fortunately, the aircraft, which was carrying 155 passengers and 6 crew members, was able to park safely, and no injuries were reported. Following the incident, the flight crew immediately notified United Airlines maintenance, and the plane was subsequently taken out of service for maintenance and troubleshooting.

The NTSB's review of the flight's data recorder confirmed the pilot's account of the incident. The data showed that the rudder surface position remained near its neutral position despite increasing force inputs to the rudder pedals during the landing and rollout. However, around 30 seconds after touchdown, the rudder pedals and rudder surface began moving as commanded and continued to operate normally for the remainder of the taxi.

On February 9th, three days after the incident, United Airlines conducted a test flight on the same plane at Newark and was able to replicate the reported rudder system malfunction. This prompted the involvement of the Federal Aviation Administration (FAA), Boeing, and Collins Aerospace in an incident investigation.

During a post-incident inspection of the rudder control system, no obvious malfunctions were found. However, when certain rudder system components were removed, United conducted a second test flight and noted that the rudder control system operated normally.

Boeing released a statement, mentioning that they worked closely with United Airlines to resolve the rudder response issue by replacing three parts. The airplane returned to service last month after the successful resolution. Boeing stated that this was the only reported incident of this nature within the 737 MAX fleet. They also mentioned two similar occurrences with the 737 NG model in 2019, which were resolved with component replacements.

United Airlines expressed their commitment to work with Boeing, the NTSB, and the FAA to determine the next steps regarding the affected aircraft. The airline clarified that the specific parts related to the rudder pedal issue were associated with a landing feature that was not selected by United and were present on only nine aircraft that were originally built for other airlines. These parts have since been replaced.

This incident adds to the ongoing scrutiny faced by Boeing's Max program. In January, a Boeing-made Alaska Airlines plane experienced a door panel blowout midair over Portland, Oregon, due to the absence of installed bolts. As a result, the FAA temporarily grounded all Boeing 737 Max 9 airplanes operating in the U.S. and increased oversight of Boeing's aircraft production.

More recently, on the 22nd of February, a Boeing 737-900 plane operated by United Airlines made an emergency landing in Florida after flames were observed shooting out of an engine. The exact cause of this incident is still under investigation.