Air Force F-35s grounded over an internal debris issue should be up and running again soon, with a few likely ready to fly before the end of this month.
The F-35 Lightning II Joint Program Office on Thursday said modifications to four of the aircraft began Oct. 7, "and the work takes about three weeks to complete."
The service on Sept. 16 ordered a temporary stand-down of 13 out of 104 F-35s in the fleet "due to the discovery of peeling and crumbling insulation in avionics cooling lines inside the fuel tanks," according to a statement at the time. Two additional aircraft, belonging to Norway and stationed at Luke Air Force Base, Arizona, were also affected.
"Rapid progress is being made in fixing 15 operational F-35A aircraft needing modifications to repair non-compliant Polyalphaolefin (PAO) coolant tubes," Joe DellaVedova, spokesman for the F-35 Joint Program Office, said in an email.
"All 15 aircraft are expected to fly again by the end of the year," he said. "At the same time, modification work is progressing on 42 production aircraft in assembly. Lockheed Martin expects to start delivering these aircraft in December. These first deliveries include jets from Israel and Japan, these nation's first deliveries."
Officials describe the Joint Strike Fighter program a global initiative, with more than eight partner countries acquiring the plane.
On Wednesday, the Norwegian ministry said it expects its two affected aircraft in the air by the end of November.
DellaVedova said engineering teams from the Joint Program Office and the aircraft's manufacturer, Lockheed Martin Corp., quickly developed solutions to fix all F-35As affected by the non-conforming coolant tubes.
"This was not a technical or design issue; it was a supply chain manufacturing quality issue," he said. "The debris came from the non-compliant PAO tubes."
Gen. Herbert "Hawk" Carlisle, commander of Air Combat Command, took aim at the aircraft's critics during the Air Force Association's annual Air, Space & Cyber conference when he said there are people "who will make comments, but will never actually have to do anything."
This "is not a design problem … it's not a developmental problem," Carlisle told reporters at the time. "It is a subcontractor that failed to perform to standards."
He said the flaw "is very contained."
Neither Carlisle nor Lt. Gen. Christopher Bogdan, executive officer for the Joint Program Office, would comment last month on which contractor supplied the coolant lines, but Bogdan said the service will use the same company going forward.
