Boeing issued a maintenance recommendation to 16 unnamed commercial airlines advising them to address a potential electrical issue in a specific group of 737 MAX jets. It did not indicate the total number of aircraft involved in the matter. “The recommendation is being made to allow for verification that a sufficient ground path exists for a component of the electrical power system,” it said.
Southwest Airlines, American Airlines, and United Airlines – three of the largest 737 MAX operators – each indicated it had removed aircraft from service.
A “ground path” refers to an aircraft’s electrical circuits and their reliability or safety within the larger aircraft operation and flight-control systems. Boeing described the current problem as “a production issue.”
Boeing confirmed that the present electrical issue did not relate to the flight-control system, the primary cause of the two crashes that led to the 737 MAX program grounding from March 2019 to December 2020. However, a wiring defect was among the issues identified for correction by Boeing and approved by the U.S. Federal Aviation Administration during the 19-month investigation that followed two crashes of the Boeing 737 MAX, from March 2019 to December 2020.
Boeing indicated that it is working with FAA on the current matter.
It also noted that the customers have been informed of specific aircraft that are affected and is instructing the carriers of appropriate corrective actions. Boeing did not indicate how long an aircraft may be out of service as the corrections are implemented.
Southwest Airlines said the new issue affects 30 of 58 737 MAX jets it now operates, and said those aircraft will be replaced by others, anticipating "minimal disruption to our operation".
American Airlines temporarily removed 17 of its 41 737 MAX planes from its service, according to a memo to employees.
United Airlines grounded 16 of its 30 737 MAX jets.
Since the FAA lifted the grounding order in December, air-safety authorities in Canada, the European Union, and Brazil have also approved the 737 MAX for operation. Some of the carriers affected by the new order may not be operating the aircraft at present.