Boeing has issued a recommendation to operators of its 737 Max airplanes to inspect for a loose bolt in the rudder control system. This advisory comes after an unnamed airline discovered a bolt with a missing nut during routine maintenance of a 737. Additionally, Boeing found a similar issue in an undelivered 737 Max, where a nut was not properly tightened.
In a statement, Boeing confirmed that the issue identified on the particular airplane has been resolved. However, as a precautionary measure, the company is advising all operators of 737 Max airplanes to conduct inspections and report any findings. Boeing has informed the Federal Aviation Administration (FAA) and its customers and pledged to keep them updated on the progress.
To date, there have been no in-service incidents caused by this bolt issue. The FAA has stated that it will remain in contact with Boeing and airlines as the inspections are carried out. Each inspection is estimated to take approximately two hours.
The FAA also noted that it would consider additional actions based on any further discovery of loose or missing hardware.
This advisory is part of ongoing quality-control issues that have affected the 737 Max. Most notably, the aircraft was grounded globally for 20 months starting in spring 2019 after two crashes that killed a total of 346 people. These crashes were linked to a faulty sensor that transmitted incorrect information to the planes' automated flight-control system, leading to nosedives.
In another incident, Boeing delayed Max deliveries in April last year after discovering that parts supplier Spirit AeroSystems used a nonstandard manufacturing process on fittings near the rear of several 737 Max planes. Deliveries resumed in May.
