A new possible problem with Boeing's 737 Max airplanes has several airlines once again pulling dozens of the troubled jets out of service.
Boeing said in a statement that it has "recommended to 16 customers that they address a potential electrical issue in a specific group of 737 MAX airplanes prior to further operations."
"We are working closely with the U.S. Federal Aviation Administration on this production issue. We are also informing our customers of specific tail numbers affected and we will provide direction on appropriate corrective actions," Boeing said.
The company said the issue is not related to the flight control software system that has been blamed in two crashes that killed 346 people. The 737 Max had only returned to commercial U.S. service in late December after the jets were grounded for some 20 months following crashes in Indonesia and Ethiopia.
The new problem is one that "could affect the operation of a backup power control unit" in newly manufactured 737 Max jets, according to the FAA. The problem apparently resulted from changes in the production process at Boeing.
In a statement, the FAA said it "recommends operators of some 737 MAX airplanes temporarily remove them from service to address a potential electrical issue. The FAA will ensure the issue is addressed. Passengers should contact airlines about possible flight delays and cancellations."
This development is the latest in a series of manufacturing flaws discovered at Boeing factories that have affected production of not just the Max, but the 787 Dreamliner and the KC-46 aerial refueling tanker.
In a statement, American Airlines says Boeing notified the airline Thursday night about "a potential production issue with a component in the electrical power system on 17 of our most recently delivered Boeing 737 MAX aircraft. At Boeing's direction, we have temporarily removed these 17 aircraft from service in order to complete necessary inspections and make any changes recommended or required by Boeing or the Federal Aviation Administration (FAA)."
American still has 24 737 Max jets in service that are not affected by the possible problem.
Southwest Airlines said it was removing from its schedule the 30 planes affected by Boeing's directive, pending further review and guidance. The carrier said it expected "very minimal operational disruption" due to the grounding of the planes.
United Airlines said it is removing 16 of the planes from its schedule and is "working to swap out aircraft to minimize the impact to our customers."
The Max is the latest iteration of Boeing's workhorse 737. Before the deadly crashes and subsequent grounding, it had been one of the most popular and profitable commercial jets the airplane manufacturer ever made. Since the Maneuvering Characteristics Augmentation System problems have been resolved and regulators worldwide allowed the plane to return to service, several airlines have increased future orders for the 737 Max, including Southwest and American.