aerobd.news : The U.S. military’s most sophisticated fighter aircraft fleet was temporarily suspended from operations beginning Thursday as the Defense Department worked to determine which of their platforms had a suspect part that could have caused the aircraft’s first-ever crash in September. The Pentagon’s F-35 joint program office announced Oct. 11 that flight operations would halt for all U.S. and international F-35 Joint Strike Fighters to conduct a fleet-wide inspection of an engine fuel tube.The grounding follows a Sept. 28 accident in which an F-35B crashed near Beaufort, South Carolina. The B variant is the Marine Corps vertical takeoff and landing version of the aircraft. Inspections are expected to be completed within the next two days, according to a statement issued Thursday morning. If “suspect” fuel tubes are installed, the part will be removed and replaced. If the tubes are deemed acceptable, those aircraft will return to flight status.

An investigation is ongoing to determine the circumstances of the F-35B accident in South Carolina, but the new inspection was driven from initial data, the joint program office said, adding, “The aircraft mishap board is continuing its work and the U.S. Marine Corps will provide additional information when it becomes available.” Pratt & Whitney, a subsidiary of United Technologies [UTX] that builds the F-35’s F135 engine, is actively working with the JPO to address the issue, said Glen Roberts, spokesman for the company’s military engine sector. He did not provide further comment on the issue with the suspect part, citing the ongoing crash investigation. By Thursday afternoon, many F-35 aircraft were already ready to fly again. A spokesman for the aircraft’s prime contractor Lockheed Martin [LMT] said the F-35s at the company’s facility in Forth Worth, Texas, were inspected and back on flight-ready status.

Several F-35A aircraft based at Luke Air Force Base, Arizona, were discovered Thursday to contain the suspect part, said Sean Clements, chief of media operations for the 56th Fighter Wing stationed there. “We do have some aircraft down that require further action,” he told Defense Daily. The number of affected aircraft cannot be released, but two aircraft have been inspected and deemed “good-to-go” to perform at the Fort Worth Air Alliance Show to be held Oct. 13-14, he said. Luke AFB conducts F-35 and fighter pilot and maintainer training for U.S.and international partners, to include Australia, Turkey, Italy, Norway, Singapore and South Korea. Seventy-five aircraft are based there, 22 of which are international platforms, Clements added. International partners for the F-35 include the United Kingdom, Turkey, Australia, Canada, Denmark, Italy and the Netherlands. Israel, Japan and South Korea have committed to the aircraft via foreign military sales.

The United Kingdom also confirmed via Twitter on Thursday that it had temporarily paused operations for its F-35 fleet, but continues to perform flight trials for the F-35B aircraft aboard the HMS Queen Elizabeth. The Marine Corps commandant on Wednesday touted the progress of the service’s joint strike fighter variant. Speaking to reporters at a breakfast event in Washington, D.C., Gen. Robert Neller said the aircraft’s readiness has been “surprisingly good, to the point where I’m corresponding with the commanding officer out there like ‘how are you doing this?’” Neller emphasized that the Marines’ maintenance crews have put in extra effort to get the F-35B prepared to deal with harsh environments in the Middle East. The aircraft recently made its combat debut in Afghanistan, just one day before the accident in South Carolina. Neller would not comment on any operational details.

Despite the dramatic grounding of more than 320 jets in one day, Pentagon and program sources said this issue should not be as time-consuming as the 2016 suspension of 13 F-35A aircraft due to issues with the cooling lines inside fuel tanks (Defense Daily, Sept. 20, 2016). The F-35 customers are investigating each aircraft to identify which possess the suspect fuel tube, and in the case that the part is detected, replacement should take place in a couple of days at most, said a source close to the program.

But the flight operations suspension comes just days after reports emerged that Defense Secretary Jim Mattis issued a memo ordering each service to increase mission-capable rates for several fighter aircraft to 80 percent by the end of fiscal year 2019. Defense News, who first reported on the memo, noted that Mattis targeted the Air Force’s F-16 Fighting Falcon and F-22 Raptor fleets, the Navy’s F/A-18 Super Hornet aircraft and the collective F-35 fleets. Neller noted that in FY’17, “we had a horrible year in aviation readiness.” “I would attribute that to the fact that we’re flying a lot more than we were, but we’re still struggling with getting to the readiness level that we want,” he said. He added that the Marine Corps would work to meet Mattis’ goal for fighter readiness. “He’s told us we’ve got a year. I know where we are right now, and he said here’s where I want to be in a year,” he said. “The good news is, we’ve got a budget.”

source : Defense Daily