Alaska Airlines and United Airlines reported that loose bolts and hardware were found when the carriers conducted inspections of their respective Boeing 737-9 MAX fleets.
In a statement released January 8, 2024, Alaska Airlines said maintenance technicians reported “loose hardware” visible on some aircraft.
“All aircraft will be thoroughly inspected in accordance with detailed instructions provided by the FAA in consultation with Boeing. Any findings will be fully addressed in a matter that satisfies our safety standards and FAA compliance,” Alaska Airlines said.
The carrier also said that none of its B737-9 MAX aircraft will be returned to service until all of the formal inspections have been completed.
Meanwhile, aviation industry publication Air Current reported that United Airlines found loose bolts “and other parts” on B737-9 MAX plug doors during inspection of Boeing jets in its fleet.
A person familiar with the findings told Air Current that the discrepant bolts and parts were found on at least five aircraft. The publication also noted there was “little consistency” in the locations of the errant part across all five of the aircraft.
In one report seen by Air Current, the airline found that bolts used to attach the lower hinge door were not fully seated, and the washers on the bolts could spin.
On another aircraft, loose bolts were found on the upper forward guide fitting on the plug and another on the forward glide roller attached to the fuselage on the door frame.
“Since we began preliminary inspections on Saturday, we have found instances that appear to relate to installation issues in the door plug. For example, bolts that needed additional tightening. These findings will be remedied by our Tech Ops team to safely return the aircraft to service,” United said in a statement seen by several media outlets.
The US Federal Aviation Administration (FAA) said that the Boeing 737-9 MAX aircraft will remain grounded until operators complete enhanced inspections which include both left and right cabin door exit plugs, door components, and fasteners.
The FAA added that operators must also complete corrective action requirements based on findings from the inspections prior to bringing any aircraft back into service.