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October 16, 2018 | International, Aerospace

Most F-35s return to flight operations after fuel tube problem

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WASHINGTON — After a fuel tube problem sidelined all operational F-35 aircraft last week, more than 80 percent of jets have been cleared to return to flight, the F-35 joint program office stated Monday.

In a Oct. 15 statement, the JPO confirmed that the U.S. services and international partners have completed inspections of their F-35 inventories for faulty fuel tubes. The aircraft that are not impacted by the bad tubes — which are a component in Pratt & Whitney's F135 engine — are back in flying status.

“The F-35 Joint Program Office continues to work closely with the military services to prioritize fuel tube replacements using the current spares inventory,” the JPO said. “Pratt & Whitney is rapidly procuring more parts to minimize the overall repair timeline for the remaining jets. Current inventory will restore about half of the impacted jets to flight operations, and the remaining aircraft are expected to be cleared for flight over the coming weeks.”

Last week, all U.S. and international F-35s were momentarily grounded to allow for an enterprise-wide fuel tube inspection. The review began as a result of an investigation into a Sept. 28 Marine Corps' F-35B crash near Marine Corps Air Station Beaufort in South Carolina — the first F-35 crash in the jet's history.

It is still unclear exactly how the defective fuel tubes impact the jet's performance or how serious a safety threat they pose during flight operations. Joe DellaVedova, a spokesman for the JPO, declined to discuss the specific problems that led the program office to call for a fleetwide inspection, saying that details could not be released until the Marine Corps completes its accident investigation.

Also still up in the air is whether the Pentagon or Pratt & Whitney will be stuck paying the tab for retrofitting the fleet.

Spokesmen from the U.S. Air Force, Marine Corps and Navy declined to lay out exactly how many of their aircraft had been impacted by the faulty fuel tubes. However, as Lockheed Martin delivered its 300th F-35 in June, 20 percent of the operational F-35 fleet can be estimated to be about 60 aircraft across the U.S. and international operators.

The JPO called the fuel tube problem an “isolated incident” that would not impact F-35 deliveries. A total of 91 F-35s are planned to be delivered to the U.S. military and foreign customers this year.

“The primary goal following any mishap is the prevention of future incidents,” the office said. “We will take every measure to ensure safe operations while we deliver, sustain and modernize the F-35 for the warfighter and our defense partners.”

The problem with the defective fuel tubes is the latest in a string of recent supply chain issues that have plagued F-35 prime contractor Lockheed Martin and engine manufacturer Pratt & Whitney, and comes as Defense Secretary Jim Mattis sent a memo directing the Air Force, Marine Corps and Navy to boost the F-35′s mission capable rate to 80 percent.

The Pentagon halted F-35 deliveries in March amid disagreements over whether the department or Lockheed should foot the bill for retrofitting part of the fleet that had not received corrosion-preventing primer in certain fastener holes. Deliveries resumed in May once the parties hammered out an agreement — although it was never revealed to the public exactly how the expenses would be paid off.

In 2016, certain F-35As were grounded after it was found that coolant lines inside the jets' fuel tanks were rimmed with faulty insulation, which was prone to disintegrating.

https://www.defensenews.com/air/2018/10/15/most-f-35s-return-to-flight-operations-after-fuel-tube-problem

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    Valerie Insinna WASHINGTON — In 2022, the U.S. Air Force will take delivery of the F-15EX, a new and improved version of the nearly 40-year-old F-15E Strike Eagle. But for all of the modern advances of the new jet, only 9 percent of women in the Air Force currently meet the body-size standards for piloting the legacy F-15 and possibly also the new EX variant, potentially blocking highly qualified pilots from flying a platform that will be in operation for decades to come. Like the vast majority of the Air Force's aircraft and aircrew equipment, the F-15 was designed to meet the anthropometric specifications of a male pilot in 1967. But in an Aug. 4 memo, the Air Force mandated that future weapons programs use current body size data that reflects the central 95 percent of the U.S. recruitment population — a move meant to make pilot and aircrew jobs more accessible to women and people of color. Air Force acquisition executive Will Roper, who signed off on the changes, said there is a strategic imperative for opening the door to a more diverse pool of pilots and aircrew. During a war with a near-peer, technologically advanced nation like China, the U.S. military will have to contend with a well-trained, highly educated force that might outnumber its own, he said. By fielding weapon systems that can only be used by a smaller portion of the U.S. population, the Air Force could be shutting out some of its most promising potential pilots or aircrew. “The human factor is a delineator and it likely will be against an adversary like China, where I believe we will have a greater propensity to trust the operator in the seat, to delegate more, to empower more and take greater risk in that delegation,” Roper told Defense News in an exclusive Aug. 6 interview. “All well and good when you're a country that's going to face a country with a population that's four times your own by the end of this decade,” he said. “But if we begin with a recruitment population that we've artificially halved because of how we design our cockpits and workstations, we've just doubled our work, and now we make every operator in the seat have to be eight times better than the counterpart they will face in a nation like China.” The new guidance directs the Air Force Lifecycle Management Center to conduct a study that will solidify a more inclusive anthropometric standard that would include 95 percent of the U.S. population eligible for recruitment in the U.S. Air Force. But until that wraps up, all new-start Air Force programs must be designed with cockpits, aircrew operating stations and aircrew equipment that accommodates eight anthropometric data sets. These eight cases use measurement data from the Centers for Disease Control and represent a range of body types including individuals who are short in stature, have short limbs or have a long torso. AFLCMC's Airman's Accommodations Laboratory will also run a three-year study that will develop separate anthropometric standards for career enlisted aviators, who perform specialized jobs onboard military aircraft including flight engineers, flight attendants and loadmasters. Currently, career enlisted aviators also must meet the 1967 anthropometric standards. ‘A hidden barrier' The legacy design parameters — which stem from a 1967 survey of male pilots and measure everything from a pilot's standing height, eye height while sitting, and reach — have effectively barred 44 percent of women from being able to fly aircraft unless they receive a waiver, with women of color disproportionately affected, the Air Force stated. Even after a waiver is granted, the pilot will remain disqualified from certain platforms regardless of his or her aptitude. Then, when future requirements are defined for new platforms or equipment, the systems are usually designed to meet the existing pool of pilots, creating a self-perpetuating problem. “It is a hidden barrier with multiple layers,” said Lt. Col. Jessica Ruttenber, an Air Force mobility planner and a leader of the Women's Initiative Team that advocated for the change in anthropometric standards. “People are trying to do the right thing, but the barriers are baked into legacy policy. And without even knowing it, they're kind of cut and pasting the same standard.” Ruttenber said the new guidance addresses the root of the problem by establishing new design specifications — ensuring platforms are engineered to accommodate a wide range of body sizes from the start of the development process, rather than papering over the problem with waivers after the fact. “[For] the next inter-theater airlift that is going to replace the C-130 or C-17, we can't get the anthropometric data wrong or women are still going to be eliminated 30 years from now. The C-130 and C-17 still eliminate one out of three women from flying it,” she said. For more than a year, the Women's Initiative Group worked with Chief Master Sgt. Chris Dawson, the career field manager for the Air National Guard's career enlisted aviators, on trying to garner funding for an anthropometric study for CEAs. “There were so many communities we had to coordinate with that we realized really quickly that this has to come from the top down or we're not going to be as successful,” Ruttenber said. After meeting with Roper, the Women's Initiative group was granted $4 million for the study. Ruttenber, a KC-135 pilot, remembers being pulled out of her first pilot training class in 2005 because her physical examination indicated that she didn't meet the standing height requirement of 5-foot-4 by a fraction of an inch. She then sought a waiver that would allow her to fly. “The process was different back then. I had to drive from base to base and get measured in each cockpit in an attempt to get an exception to policy. I went to Charleston and I got measured in a C-17, and then I went to Little Rock and got measured in a C-130,” she said. “I got measured in the KC-135 and so on and so on and so on.” Since then, the Air Force has made the process to obtain a waiver less arduous, and it recently removed the initial height requirement — although some platforms still require pilots to meet the 5-foot-4 standard. Newer aircraft such as the F-35 joint strike fighter and the T-7 trainer currently under development will also accommodate a wider height and weight range. However, Ruttenber pointed out that the specifications for legacy aircraft will remain a hurdle for the progression of female pilots. “Even if the F-35 is 97 percent accommodating for women, I still can't get there because the T-38,” which is used for fighter pilot training, “has a 41 percent accommodation envelope for women,” she said. Roper said he is working with defense contractors to see whether there can be modifications made to legacy platforms — or upgraded versions like the F-15EX — that will accommodate operators with a wider range of body sizes. But whether those changes are ultimately made will depend on if they are technically feasible and funding is available for design changes. At the time of the Aug. 6 interview, Roper had already spoken to some defense industry executives — including those from Lockheed Martin — about the new guidance and planned similar phone calls with Boeing and Northrop Grumman officials over the coming days. The reaction from industry so far has been “very positive” but “very surprised” that such bias still exists, he said. However, Roper acknowledged that more work has yet to be done. “Changing the policy is one thing. Changing the platforms is another. And that's going to require cost to do. My next job, aside from designing future systems differently — which we'll do — is to find options to bring systems into greater compliance with the new policy and then to advocate tooth and nail for the funding needed to do it,” he said. “The litmus test for the Air Force long term has got to be balancing accommodation with the technology for future platforms.” https://www.airforcetimes.com/news/your-air-force/2020/08/19/to-get-more-female-pilots-the-air-force-is-changing-the-way-it-designs-weapons/

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