(NewsNation) — Boeing was notified of yet another potential issue in some of its 737 jet fuselages last Thursday.
Boeing Commercial Airplanes CEO Stan Deal said in a letter to Boeing staff seen Monday that a worker at its supplier discovered misdrilled holes in fuselages. Spirit AeroSystems, based in Wichita, Kansas, makes a large part of the fuselages on Boeing Max jets.
“While this potential condition is not an immediate safety issue and all 737s can continue operating safely, we currently believe we will have to perform rework on about 50 undelivered planes,” Deal said in the letter to employees shared with the media.
The problem was discovered by an employee of the supplier of the fuselages who notified his manager that two holes might have not been drilled according to specifications, Deal said.
Deal also announced the company will spend several days in the Renton factory to focus on the quality of production and to ensure undelivered planes are scanned for any non-conformities.
Both Boeing and Spirit AeroSystems are facing intense scrutiny over the quality of their work after an Alaska Airlines 737 Max 9 was forced to make an emergency landing on Jan. 5 when a panel called a door plug blew out of the side of the plane shortly after takeoff from Portland, Oregon.
The National Transportation Safety Board is investigating the accident, while the Federal Aviation Administration investigates whether Boeing and its suppliers followed quality-control procedures.
“We’re currently in a program of stepped-up oversight of the Boeing Renton factory, the 737 MAX line, we’re doing a nose to tail wingtip to wingtip inspection. And as we get findings out of that inspection, we anticipate that that will drive our reimagined oversight,” Jodi Baker, deputy associate administrator for aviation safety at the FAA, said in a press conference.
Baker says the FAA will conduct audits of its certification systems, in addition to increased surveillance of Boeing’s manufacturing systems.
Alaska Airlines and United Airlines, the only other U.S. airline flying the Max 9, reported finding loose hardware in door plugs of other planes they inspected after the accident. The FAA grounded all Max 9s in the U.S. the day after the blowout. Two weeks later, the agency approved the inspection and maintenance process to return the planes to flying.
Alaska Airlines and United Airlines have begun returning some to service.
The Associated Press contributed to this report.