The U.S. Federal Aviation Administration has approved a "thorough inspection and maintenance process" for the 171 grounded Boeing Max 737-9 aircraft, the agency announced Wednesday. Upon successful completion of the process, which is expected to take about 12 hours per plane, the aircraft will be allowed to return to service.
The aircraft have been grounded since Jan. 6 after a Jan. 5 incident in which a door plug flew off during an Alaska Airlines flight from Portland. Ore., to Ontario, Calif.
"The exhaustive, enhanced review our team completed after several weeks of information gathering gives me and the FAA confidence to proceed to the inspection and maintenance phase," FAA administrator Mike Whitaker said in a statement.
Alaska Airlines on Jan. 26 plans to resume flying the first of its 65 Max-9 planes, the carrier announced Wednesday, "with more planes added every day as inspections are completed and each aircraft is deemed airworthy." The carrier expects all inspections of the grounded aircraft to be completed over the next week.
United Airlines expects to resume flying its 79 grounded Boeing Max. 737-9 planes on Jan. 28, according to an internal memo from United EVP and chief operations officer Toby Enqvist. "We will only return each Max 9 aircraft to service once this thorough inspection process is complete," he said. "We are preparing aircraft to return to scheduled service beginning on Sunday."
Copa Airlines also is following the inspection process for its 21 grounded aircraft and will gradually reinstate flights that had been canceled, beginning today, it announced Thursday. It expects to return to a full schedule on Jan. 28.
Whitaker also added that though the Max-9 inspections have been approved, "this won't be back to business as usual for Boeing," he said. "We will not agree to any request from Boeing for an expansion in production or approve additional production lines for the 737 Max until we are satisfied that the quality control issues uncovered during this process are resolved."
The agency has increased its oversight activities of new Boeing Max 737 aircraft and is launching an investigation into Boeing's compliance with manufacturing requirements.