AFMC orders all C-130s inspected, Dyess already completed

  • Published
  • By Capt. Bob Everdeen
  • Air Force Materiel Command Public Affairs
WRIGHT-PATTERSON AIR FORCE BASE, Ohio --  An immediate action time compliance technical order was issued by Air Force Materiel Command officials here March 4 to inspect all C-130 Hercules aircraft due to potential cracking of wing-joint barrel nuts. All 33 of Dyess C-130s were inspected within 12 hours.

The time compliance technical order was ordered after a C-130H undergoing routine scheduled maintenance at Warner Robins Air Logistics Center, Ga., was found with five of its upper 13 barrel nuts cracked.

The C-130 outer wing is attached to the center wing with 28 bolts and barrel nuts -- 13 upper and 15 lower -- on each side of the aircraft. The lower wing barrel nuts are not affected.

Within the first three days after the time compliance technical order was issued, more than two-thirds of the Air Force fleet of nearly 600 aircraft had been inspected, and more than 40 percent returned to flight. Priority shipments of replacement barrel nuts are going to C-130 units at forward-deployed locations, and those with special operations and aeromedical missions.

Dyess C-130 mechanics discovered some of the planes needed barrel nuts replaced.

"Fortunately, this was an easy inspection and repair for our maintenance pros. We had great weather over the weekend, so our maintenance team sprang into action and restored the aircraft whether they were on the flightline or in a hangar for other scheduled maintenance," said Col. Bernard Mater, 317th Airlift Group commander. "They quickly visually determined whether each nut was serviceable, and if it wasn't, it was just the simple matter to take off the old nut and correctly tighten the new one. While any maintenance specialist could inspect the nuts, just a few additional specialized personnel were required to complete the inspection requirements. For example, Quality Assurance personnel inspected the repairs and verified that the proper amount of torque was applied. While the repair time and number of personnel for each airplane differs based on the number of needed replacement nuts, the superior efforts our maintenance team did not allow this inspection or needed repairs to affect our flight schedule."

The cause of the cracks appears to be hydrogen embrittlement, a process by which various metals, particularly high-strength steel, become brittle and crack after being exposed to hydrogen.

"I am really proud of our superb maintenance team. While these kinds of maintenance actions are rare, they took the task in stride so the Fightin' 3-1-7 could fly this week's planned flight operations," Col. Mater said.