Four U.S. airlines announced Friday that they are grounding almost 70 of their 737 Max jets after Boeing disclosed a potential electrical problem affecting the planes.
The problem could affect a backup power control unit on jets used by 16 Boeing customers and stems from a manufacturing problem, according to the company and the Federal Aviation Administration. Boeing said the new problem isn't connected to issues implicated in two deadly crashes involving the Max in recent years.
Southwest Airlines said it was pulling 30 of its 58 Max planes from service, while American Airlines said it would ground 17 of its 41 planes. United Airlines is pulling 16 of its 30 Max planes and Alaska Airlines will ground all four in its fleet. It wasn't clear Friday how many jets worldwide were affected.
The new problem surfaced as airlines have returned the Max to the skies after a pair of deadly crashes killed 346 people in 2018 and 2019, leading to the jets being grounded worldwide for almost two years. On Friday, American operators again were left to ensure the public that the planes were safe.
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Boeing said it would work with customers to help them with fixes, but it's not clear how long that might take.
The FAA said in a statement that Boeing alerted it to the problem late Thursday.
The agency cleared the Max to fly again in November, ordering safety fixes to address design flaws that contributed to the crashes. American Airlines became the first operator in the United States to return the jet to its fleet in late December.
American said in a statement Friday that only the planes it received after the Max was returned to service were affected.
"As we shared when we returned the 737 Max to commercial service, the safety of our customers and team members comes above all else," American said. "It's with this unequivocal standard that we rigorously maintain and monitor all our aircraft -- including the Boeing 737 Max -- to ensure every plane in the air is safe."
United said in a statement it is working with Boeing to determine when the planes could return to its fleet but said it had no estimate of a timeline.
"We have been in touch with the FAA and Boeing and will continue to work closely with them to determine any additional steps that are needed to ensure these aircraft meet our rigorous safety standards and can return to service," United said.
SOUTHWEST RESPONDS
Southwest said it had not experienced operational problems with the planes and was only using the Max in a limited capacity, with up to 15 of the planes scheduled to fly each day.
"Southwest anticipates minimal disruption to our operation, and we appreciate the understanding of our customers and employees as safety is always the uncompromising priority at Southwest Airlines," the airline said in a statement.
Boeing said the new electrical problem is unrelated to a new software system that was singled out after the crashes or to a separate wiring design problem.
"The recommendation [to ground flights] is being made to allow for verification that a sufficient ground path exists for a component of the electrical power system," Boeing said in a statement.
Appearing at a White House briefing Friday, Transportation Secretary Pete Buttigieg said officials need full confidence in the safety of the grounded aircraft before they return to the air.
The latest problem is a blow for Boeing at a time when it appeared to be recovering, securing new Max orders as airlines prepared for a rebound from the coronavirus pandemic. In late March, Southwest -- which flies only 737s -- agreed to order 100 more of the jets, putting to rest speculation that it might opt for an Airbus plane to expand its fleet.
The new disclosure follows other allegations of manufacturing and quality problems with the plane, including congressional testimony in 2019 by a former Boeing manager that he repeatedly warned company executives about production problems at the Max plant in Washington, calling it a "factory in chaos."
PREVIOUS PROBLEMS
Earlier production lapses have led the FAA to take action against Boeing.
In January 2020, the FAA said it was proposing a $5.4 million fine against the company, accusing it of saying that defective wing parts for 178 Maxes were safe to use. The agency had previously proposed a $3.9 million fine in connection with the same alleged problem on older generation 737s. The cases remain open, the FAA said.
In August, the FAA accused Boeing managers at a South Carolina plant that makes 787s of pressuring safety inspectors to rush their work. The company agreed to pay $6.6 million to resolve that case and other allegations that it didn't live up to a settlement designed to improve its safety culture.
The deadly crashes, in Indonesia and Ethiopia, led to a temporary halt to the production line while Boeing and the FAA worked to approve safety fixes for the planes. The design of the software implicated in the crashes, called the maneuvering characteristics augmentation system, was overhauled and pilots were required to receive new training.
The crashes left the reputations of Boeing and the FAA battered. In December, Congress rewrote aviation safety laws in an effort to stiffen the regulator's oversight of the company.