U.S. aviation safety officials have asked Boeing Co (BA.N) to provide new analysis and documentation showing that numerous 737 MAX subsystems will not be affected by electrical grounding problems, first noted in three areas of the aircraft in April, said two people familiar with the matter to Reuters.
Further analysis introduces new uncertainty about when Boeing̵
Electricity problems stopped almost a quarter of the 737 MAX’s fleet.
US airlines have said they expect Boeing to release service bulletins as early as this week, which will allow them to repair and return the aircraft to service soon, but the latest issue is likely to shift that deadline back.
“We continue to work closely with the FAA and our customers to address the ground problem in the affected 737s,” said a Boeing spokesman.
Asked about the status of the planes, an FAA spokesman said that “we continue to work with Boeing.”
Airlines withdrew dozens of 737 MAX aircraft early last month after Boeing warned of an electrical grounding problem related to production in a backup power management unit located in the cockpit of some recently built aircraft.
Then the problem, which stopped the delivery of new aircraft, was found in two other places in the cockpit, including the luggage rack, where the affected control unit is located, and the dashboard facing the pilots.
The problem is the latest issue of the 737 MAX, which was based for almost two years, starting in 2019 after two fatal crashes.
The slogan of questions on a relatively clear electrical issue illustrates the tighter regulatory stance facing America’s largest exporter as it tries to emerge from the 737 MAX crisis and the overlapping coronavirus pandemic.
Late last week, Boeing unveiled service bulletins advising airlines on how to fix grounding problems or electrical paths designed to maintain safety in the event of a power surge, the two said.
The FAA approved service bulletins, but then, in ongoing discussions with Boeing, asked for further analysis on whether other jet subsystems would be affected by the grounding problem, one source said. The FAA will review Boeing’s analysis and any necessary revisions to service newsletters before they can be sent to airlines.
Boeing has proposed adding a connecting strip or cable for workers to screw on two different surfaces, creating a ground path, two people said.
Boeing had originally told airlines that repairs could take hours or days on a plane.
The problem with electrical grounding came after Boeing changed its production method as it worked to speed up jet production, a third person said. A fourth person said the change improved the process of drilling holes.
The FAA issued a new airworthiness directive last week, requiring an amendment before planes resumed flights, saying the problem affected 109 planes in operation worldwide. Sources claim that this affects more than 300 aircraft in Boeing’s inventory.
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