Boeing (BA) is facing yet another problem with its 737 Max planes after reporting an electrical fault on a specific group of jets.
The company said that the “production issue” does not affect its entire fleet and told 16 operators that the jets should not be flown until it is addressed.
It is working alongside the Federal Aviation Administration (FAA) on the issue, and confirmed it was not related to the flight-control system that grounded its planes previously.
“The recommendation is being made to allow for verification that a sufficient ground path exists for a component of the electrical power system,” Boeing said.
“We are also informing our customers of specific tail numbers affected and we will provide direction on appropriate corrective actions.”
Airlines including Southwest, American and United said they had taken more than 60 planes out of service following the notice from Boeing. The issue is believed to affect about 90 planes globally, according to Bloomberg.
A Boeing spokeswoman said it was unclear how long it would take to solve the problem: “It could take a matter of hours or a few days.”
The global fleet of in-service 737 Max is currently a total of 176 aircraft, according to Cirium fleets data. Those jets are operated by 22 airlines, most based in North and South America, but with some based in Europe, Cirium shows.
It comes just months after the jets were cleared to return to the skies.
The aircraft was grounded worldwide for 20 months following two fatal crashes in Indonesia and Ethiopia that killed 346 people.
Lion Air flight JT610 crashed off Indonesia in October 2018. Five months later, Ethiopian Airlines flight ET302 crashed minutes after take-off from Addis Ababa.
However, US safety regulators cleared the plane to fly again in North America and Brazil in November last year.
The FAA said existing planes would need to be modified before going back into service, with changes to their design, while pilots would need retraining. It said the design changes it had required had "eliminated what caused these particular accidents.”
Investigators believe the accidents were triggered by the failure of a single sensor, specifically the MCAS software, as well as the regulatory oversight failures of the FAA, and the lack of training provided to pilots.
The plane also received the green light in Europe after the head of Europe's aviation safety agency, EASA, gave final clearance to resume flying at the start of this year.
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