Boeing is facing a fresh investigation over another 737 Max flaw after a plane’s rudder got stuck during landing

Boeing is facing an investigation into a 737 Max 8 incident that took place last month.

A United Airlines plane was flying from the Bahamas to Newark, New Jersey on February 6. It was delivered to the carrier a year earlier. All 161 people on board were uninjured.

In its preliminary report released Thursday, the National Transportation Safety Board said the jet experienced “stuck” rudder pedals.

The rudder pedals let pilots control the plane’s yaw, meaning which direction the nose is pointing. When landing, they help keep the aircraft on the runway’s centerline.

In a post-incident statement, the flight’s captain said the rudder pedals didn’t move in response to the “normal” application of pressure, per the NTSB’s report. Instead, the pedals were stuck in the neutral position.

It occurred during landing rollout, the phase after touchdown but before the plane slows to taxiing speed.

While on the taxiway, the captain asked the first officer to check his rudder pedals and he reported the same problem, per the report.

The pedals then began operating normally again, the captain said. The Boeing 737 Max was removed from service for maintenance and troubleshooting.

Three days later, United Airlines was able to duplicate the malfunction during a test flight on the same plane. As a result, the NTSB was called in to figure out what the problem was.

The investigation is still ongoing, with participants including United, Boeing, the Federal Aviation Administration, and Collins Aerospace — which built the rudder control system.

Boeing said it is the only report of this issue it has received with its 737 Max fleet. The rudder pedal system is the same one used in the previous generation, the 737 NG. Boeing said it knows two similar occurrences on that model, both in 2019. The issue was solved by replacing the component, it added.

“We appreciate the NTSB’s work on this preliminary report and will continue to fully support their investigation,” Boeing said in a statement shared with Business Insider.

“With coordination with United, the issue was successfully resolved with the replacement of three parts and the airplane returned to service last month,” it added.

Boeing has been under renewed scrutiny since January’s Alaska Airlines blowout, involving a 737 Max 9.

The NTSB’s preliminary report said the plane left Boeing’s factory without key bolts in place.