Boeing Commercial Airplanes has instructed 737 MAX jet operators to inspect all aircraft for a possible defect in the rudder control system after a non-U.S. carrier reported a loose bolt during routine maintenance. That detail was reported by the U.S. Federal Aviation Administration, which added: “The company (Boeing) discovered an additional undelivered aircraft with a nut that was not properly tightened.”
“The issue identified on the particular airplane has been remedied,” according to a Boeing a statement. “Out of an abundance of caution, we are recommending operators inspect their 737 MAX airplanes and inform us of any findings.”
The inspections will take about two hours to completed on each jet, according to Boeing, and all new 737 MAX jets will be checked before delivery.
There has been no information on the cause of the loose bolt, but the matter represents a new detail in a series of problems for Boeing’s manufacturing supply chain in recent months.
While Boeing has largely recovered from the disruption to the 737 MAX program resulting from the 20-month shutdown to identify and repair the cause of two fatal accidents in 2018 and 2019, it has reportedly struggled to increase the production rate for the twin-engine, narrow-body jets. That hurdle is important to Boeing’s overall performance, as commercial aircraft demand is increasing due to fleet modernization and expansion programs.
The 737 MAX is Boeing’s top-selling model, with more than 1,300 of the aircraft in service and about 4,500 more on order or awaiting delivery.