The possible electrical problem that caused airlines to take dozens of 737 MAX aircraft out of service last week affects more areas of the plane’s flight deck than were previously known, Boeing Co. said Friday.
The aerospace giant said last week that it had told 16 MAX operators to inspect their planes to find a possible electrical problem that was identified during the assembly of a plane in Seattle. The manufacturing problem, which Boeing now says affects components at some locations, will have to be addressed on approximately 90 aircraft in airline fleets, as well as on many undelivered aircraft.
Airlines have been eager to put their MAX aircraft back into service as they prepare for a busy summer, but airlines have said they have been able to manage without the aircraft by replacing other aircraft. Still, the newly discovered flaw threatens to undermine the efforts of airlines and Boeing to restore passenger confidence on the plane. This challenge comes when the aircraft manufacturer is also working to solve quality problems that have plagued some of its other commercial and military aircraft.
The problem reported last week involved the electrical grounding path of the standby power unit in some of the aircraft’s electronic systems. A change in the way this unit was installed during production in early 2019 could have disrupted this dirt road; in some circumstances, this could affect the operation of the security power supply, Boeing, the Federal Aviation Administration and airlines said last week.
The same production changes also affected the ground clearance of the aircraft’s main instrument panel and the frame that houses the standby power unit, Boeing found during its recent assessments. These areas also need to be inspected and modified, Boeing said.