(Bloomberg) -- Aviation regulators in the U.S. are expanding the inspections that were ordered in October for part of the structure that helps attach the wings on Boeing Co. 737 NG aircraft.
The Federal Aviation Administration said in a notice to be posted Wednesday in the Federal Register that the areas to be inspected are being expanded to more fasteners.
Four planes examined in the original order were found to have cracking outside the initial inspection area, the agency said in the order. The inspections had to be expanded “to adequately address the unsafe condition,” it said.
Boeing said the additional inspections were already underway. “We regret the impact to our customers and have a repair plan in place to address any findings,” it said in a statement.
Of about 1,200 airplanes subject to the initial inspections, less than 5%, were found to have cracks, the Chicago-based planemaker said. The four planes in which the secondary issue was discovered include three that were in service and one that was undergoing maintenance.
Airlines have 60 days to conduct the new inspections on planes with at least 30,000 total flights, Boeing said in its statement. Planes with 22,600 to 30,000 flights must be inspected before they conduct another 1,000 flights.
In the original order in October, before expanding the areas that must be examined for cracks, the FAA said airlines had to inspect planes with more than 30,000 flights within seven days. The inspection regime was the same for planes with 22,600 to 30,000 flights. The part under scrutiny is known as a pickle fork.
Southwest Airlines Co. has begun the new inspections and will meet the agency’s timeline with no anticipated impact on service, said Brandy King, a spokeswoman. The carrier previously found three aircraft with cracking that were taken out of service and await repairs. The airline voluntarily is inspecting all of the 737 NG aircraft in its fleet.
American Airlines Group Inc. has begun inspecting the 737-800s in its fleet, the lone model it operates subject to the order, and hasn’t found any cracks so far, said Ross Feinstein, a spokesman for the Fort Worth, Texas-based carrier. All of American’s 737-800s have less than 30,000 cycles, so it wasn’t required to perform the inspections immediately.
Delta Air Lines Inc. hasn’t found any cracks in inspections of its fleet, said Morgan Durrant, a spokesman for the carrier. Delta doesn’t expect the checks to affect its operations, Durrant said.
The plane’s latest version, known as the 737 Max, isn’t affected. Those airplanes are grounded worldwide following a pair of fatal crashes, in Indonesia and Ethiopia.
An FAA order only applies to U.S. carriers, but regulators in other nations typically follow the agency’s lead on such issues.
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