By JENNIFER H. SVAN | STARS AND STRIPES Published: August 22, 2019

KAISERSLAUTERN, Germany — The Air Force has completed inspections of more than a quarter of its fleet of C-130 Hercules transports, which were pulled from flying operations after the discovery of signs of cracking on the wing joints.

Of 113 aircraft inspected, all but one have been cleared to return to operational duty, Air Mobility Command said Wednesday.

Ten other aircraft singled out for inspection were already undergoing depot maintenance and will be inspected on schedule, officials said.

“This process has been swift, deliberate and effective,” Col. Jed McCray, AMC associate director of logistics, engineering and force protection, said in a statement. “Of the 113 C-130s inspected, only one has been found to have a rainbow fitting crack, and that aircraft will require depot-level maintenance to repair it and bring it back into service. All others have been returned to duty without issue.”

The upper and lower rainbow fittings connect the outer wings with the center wing box, which sits over the fuselage on a C-130.

AMC Commander Gen. Maryanne Miller ordered on Aug. 7 the temporary grounding of 123 C-130 H- and J-model C-130s, a move that affected more than a quarter of the 450 C-130 aircraft in Air Force inventory.

The suspension came after maintainers discovered cracks on the lower center wing joint on an Air National Guard C-130H model at Robins Air Force Base, Ga., during depot maintenance.

Miller’s order applied to C-130s in the fleet that had yet to receive an extended service life center wing box and had logged more than 15,000 flight hours.

Each inspection for cracks took about eight hours. AMC said if cracking was identified, the plane would either be flown to depot or a depot team would be brought to the aircraft locations, depending on the severity of the findings.

The statement did not say where the aircraft found to have cracks was based and where it would be repaired.

The grounding did not affect the Hercules’ support to overseas contingency operations, AMC said.

At Ramstein Air Base, Germany, where the 37th Airlift Squadron provides airlift support to military missions across Europe and Africa, only one of its C-130Js was pulled for an inspection; it was immediately returned to service after no cracks were found.

The Air Force over a decade ago began replacing center wing boxes on all C-130 models except the C-130J — the newest model in the fleet — after center wing boxes began showing cracks earlier than expected.

The four-turboprop Hercules has been the workhorse of the wars in Afghanistan and Iraq, regularly ferrying troops and flying weapons, ammunition, food, medicine and other supplies to isolated outposts.