Washington(CNN) For the second time in two months, the US Air Force has stopped accepting deliveries of new Boeing KC-46 tanker and refueling aircraft after debris was again found in some of the planes coming off the production line.
"We actually stopped again the acceptance of the KC-46s because of foreign object debris that we found in some closed compartments," Air Force Secretary Heather Wilson told Congress Tuesday.
"We've got corrective action in place, including (inspections) in some of those closed compartments to make sure that the production line is being run the way that it needs to be run," she said.
The issue remains a quality control failure and "unrelated to design or engineering specifications," according to Ann Stefanek, an Air Force spokeswoman.
CNN reported last month that the Air Force first halted deliveries on February 20 after trash and industrial tools — known as foreign object debris, or FOD — were found on board some planes after production was completed.
Deliveries resumed several days later after Boeing agreed to an additional inspections plan.
But "this week our inspectors identified additional foreign object debris and areas where Boeing did not meet quality standards," Stefanek said.
A Boeing spokesperson called resolving the issue "a company and program priority."
"Boeing is committed to delivering FOD-free aircraft to the Air Force. Although we've made improvements to date, we can do better," company spokesperson Charles Ramey told CNN.
"We are currently conducting additional company and customer inspections of the jets and have implemented preventative action plans. We have also incorporated additional training, more rigorous clean-as-you-go practices and FOD awareness days across the company to stress the importance and urgency of this issue. Safety and quality are our highest priority," he added.
The Air Force and Boeing are meeting to approve additional corrective action plans before aircraft acceptance can resume, according to Stefanek.