F-35 - News and Discussions | Page 14 | World Defense

F-35 - News and Discussions

Khafee

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Lockheed expects slowed production due to COVID-19, F-35 to be hit hardest
By Christen McCurdy
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The first F-35A Lightning II assigned to the 354th Fighter Wing lands at Eielson Air Force Base, Alaska on Tuesday. Photo by Zade Vadnais/U.S. Air Force

UPI) -- Lockheed Martin expects lower sales and slower deliveries for some of its programs in in the coming months -- particularly the F-35.

In an earnings call, Marillyn Hewson, Lockheed's chairman, president and CEO, said the company has reduced its 2020 sales expectations due to disruptions caused by the COVID-19 pandemic.

Ken Possenriede, Lockheed's chief financial officer, said the F-35 program has been the hardest hit by the pandemic due to problems with the supply chain, with workforce disruption and shipping constraints among the issues.

Lockheed Martin is the world's largest defense contractor, supplying aircraft including the F-35, the C-130J, the C-5 and missiles and fire control programs for the Pentagon and allied militaries around the world.

The company said in a press release ahead of the call that it "is beginning to experience some issues in each of its business areas related to COVID-19, primarily in access to some locations and delays of supplier deliveries."

Officials added that the company expects that expectations for sales, earnings and cash flows could be impaired.

Lockheed reported $64 billion in net sales and $672 million in operating profit in the first quarter of 2020, versus $56 billion in net sales and $585 million operating profit in the first quarter of 2019.

According to Lockheed, that increase was primarily due to higher net sales of F-35s, which the contractor manufactures for the Air Force, Marine Corps and Navy, as well as several foreign militaries.

On Tuesday, Eielson Air Force Base in Fairbanks, Alaska, received its first two F-35A Lightning II fighter aircraft from Lockheed, with 52 more scheduled for delivery by the end of 2021.

Net sales for the F-35 program were up $695 million, and operating profit for the program increased by $80 million -- about the amount of money it costs to produce one F-35.

On Monday, Department of Defense officials said they anticipate a three-month delay across the Major Defense Acquisition program due to the pandemic, with undersecretary of defense acquisitions Ellen Lord saying aviation was "the most highly impacted" sector in defense contracting so far.
 

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The Pentagon will have to live with limits on F-35’s supersonic flights

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The first F-35C Lightning II sortie takes off from the U.S. Navy F-35 Strike Fighter Squadron VFA 101 at Eglin Air Force Base, Fla. A design issues means the Navy's and Marine Corps' F-35 versions will have some limits on supersonic flights. (Samuel King Jr./U.S. Air Force)

WASHINGTON — An issue that risks damage to the F-35’s tail section if the aircraft needs to maintain supersonic speeds is not worth fixing and will instead be addressed by changing the operating parameters, the F-35 Joint Program Office told Defense News in a statement Friday.

The deficiency, first reported by Defense News in 2019, means that at extremely high altitudes, the U.S. Navy’s and Marine Corps’ versions of the F-35 jet can only fly at supersonic speeds for short bursts of time before there is a risk of structural damage and loss of stealth capability.

The problem may make it impossible for the Navy’s F-35C to conduct supersonic intercepts.

“This issue was closed on December 17, 2019 with no further actions and concurrence from the U.S. services,” the F-35 JPO statement read. “The [deficiency report] was closed under the category of ‘no plan to correct,’ which is used by the F-35 team when the operator value provided by a complete fix does not justify the estimated cost of that fix.

“In this case, the solution would require a lengthy development and flight testing of a material coating that can tolerate the flight environment for unlimited time while satisfying the weight and other requirements of a control surface. Instead, the issue is being addressed procedurally by imposing a time limit on high-speed flight.”

The carrier-launched "C" variant and the short-takeoff-and-vertical-landing "B" version will both be able to carry out all their missions without correcting the deficiency, the JPO said.

The potential damage from sustained high speeds would influence not only the F-35’s airframe and the low-observable coating that keeps it stealthy, but also the myriad antennas located on the back of the plane that are currently vulnerable to damage, according to documents exclusively obtained by Defense News

The JPO had classified the issues for the "B" and "C" models as separate category 1 deficiencies, indicating in one document that the problem presents a challenge to accomplishing one of the key missions of the fighter jet. In this scale, category 1 represents the most serious type of deficiency.

While it may seem dire that an aircraft procured for flying at supersonic speeds will be unable to do so for extended periods, the F-35 may not need to do it that often.

For the F-35, as opposed to the F-22 where supersonic flight is baked into its tactics, the ability to fly supersonic is more of a “break glass in case of emergency” feature, said Bryan Clark, an analyst with the Hudson Institute and a retired naval officer.

“Supersonic flight is not a big feature of the F-35,” Clark said. “It’s capable of it, but when you talk to F-35 pilots, they’ll say they’d fly supersonic in such limited times and cases that — while having the ability is nice because you never know when you are going to need to run away from something very fast — it’s just not a main feature for their tactics.”

In fact, going supersonic obviates the main advantages of the F-35, Clark said. “It sort of defeats all the main advantages of the F-35,” he explained. “It takes you out of stealthiness, it burns gas like crazy so you lose the range benefits of a single engine and larger fuel tank. When you go into afterburner, you are heating up the outside of your aircraft.”

That creates all kinds of signatures that can be detected by an adversary, Clark said.

What if?
But a retired naval aviator told Defense News last year that the limitations on the afterburner could prove deadly in close-combat scenarios.

The concept of operations for the F-35 is to kill an enemy aircraft before it can detect the fighter jet, but relying on long-range kills is a perspective that, for historical and cultural reasons, naval aviation distrusts. In the Vietnam War, when air warfare began heavily relying on missiles and moved away from the forward gun, it caused a spike in air-to-air combat deaths.

The lesson naval aviation took away was to prevent the latest and greatest technology from offsetting the learning of fundamentals, and it was the impetus behind the formation of Top Gun 50 years ago, a naval strike fighter course for training and tactics development.

“The solution is: ‘Hey, we’ll just limit the afterburner to less than a minute at a time,’ ” a retired naval aviator said when told of the issue. “Which, with what the aircraft is supposed to do and be capable of, that’s a pretty significant limitation.”

Primarily it would be an issue if the aircraft had to maneuver at high speeds to avoid a missile or survive a dogfight.



The issue is compounded for the Navy, which must operate forward for months at a time, because any significant issues with coatings or the structure of aircraft would require a depot-level repair. And so a damaged aircraft would remain damaged until its host ship returns to home port, reducing the combat effectiveness of the air wing.

“We might have to be operating at sea for eight months, so if you damage something on week one, guess what? It’s damaged for the rest of the deployment,” the aviator said. “And it affects your ability to evade detection by the enemy — you just degraded that asset permanently until you can get it somewhere where it can be fixed, at great expense and time.”

Other deficiencies

Three other category 1 deficiencies have also been officially designated as “closed," meaning they have either been fixed or the performance of the aircraft is being accepted as is, the JPO reported.

The so-called green glow deficiency has been closed out as of last July. Green glow refers to a green light emitted by the helmet-mounted display’s LED lights. That glow obstructs a pilot’s view of an aircraft carrier’s deck lights during landing operations at sea in very low light, such as that experienced at night.

The issue was closed “as a result of incorporating an improved Organic Light-Emitting Diode (OLED) Helmet Mounted Display (HMD),” the JPO told Defense News.

“The Generation III F-35 OLED Helmet Display Unit (HDU) significantly reduced the ‘green glow’ experienced by pilots during night operations. The F-35 JPO has taken delivery of the first order of F-35 OLED HDUs to support the U.S. Navy (USN) and U.S. Marine Corps (USMC), and a second order of OLED HDUs has been placed,” the office’s statement read.

An issue created when the F-35A and F-35B blow a tire, which can result in a severed hydraulic line, will remain uncorrected, the JPO statement said, but it has not come up again since the program switched tires.

“The DR [deficiency report] was closed under the category of ‘no plan to correct’ based on the fact that the landing gear system design meets all F-35 safety standards,” the statement read. “Issues related to premature bursting of tires were resolved by tire design changes during early F-35 development and no instances of dual hydraulic system loss caused by a tire burst have ever been observed on an F-35.”

And an issue that forced the F-35 to land in cold weather because of battery trouble has been fixed, the JPO said. The issue was caused by extreme cold entering the plane when the doors to the jet’s nose landing gear were open, setting off alarm bells, according to “for official use only” documents exclusively obtained by Defense News.

The cold would enter the plane and overwhelm the battery heater blanket, which is installed to keep a 28-volt battery running at peak condition. The battery would not shut down, but because of the cold, the blanket could not heat the battery as quickly as intended, triggering warning lights in the cockpit that the battery was going to fail.

A software upgrade fixed the problem, the JPO said.

“This issue was resolved on July 22, 2019 due to improvements in the battery charger’s firmware,” the statement read. “The firmware changes were developed by the battery charger supplier, and integrated and tested by Lockheed Martin and the F-35 Lightning II Joint Program Office.”
 

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The Pentagon has cut the number of serious F-35 technical flaws in half
By: Valerie Insinna
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WASHINGTON — The U.S. Defense Department is slowly but surely whittling down the number of F-35 technical problems, with the fighter jet program’s most serious issues decreasing from 13 to seven over the past year.

In June 2019, Defense News published an investigation delving into the details of 13 previously unreported category 1 deficiencies — the designation given to major flaws that impact safety or mission effectiveness.

Following the report, five of those 13 category 1 problems have been “closed,” meaning they were eliminated or sufficiently corrected. Five were downgraded to a lower level of deficiency after actions were taken to help mitigate negative effects, and three issues remain open and unsolved, according to the F-35 program executive office.

Four additional CAT 1 problems have also since been added to the list, raising the total CAT 1 deficiencies to seven. The program office declined to provide additional details about those issues for classification reasons, but stated that software updates should allow all of them to be closed by the end of 2020.

“The F-35 Lightning II Joint Program Office is keenly aware of these existing F-35-related category 1 deficiencies and is focused on developing and implementing solutions for these issues as quickly as possible,” the program office said in response to questions from Defense News. “F-35 operator safety is the F-35 JPO’s highest priority.”

In a statement to Defense News, F-35 manufacturer Lockheed Martin confirmed the number of open category 1 deficiencies. However, the company declined to provide further information about the path to fix current issues or how earlier issues had been ameliorated.

“We are actively addressing the deficiencies and expect all to be downgraded or closed this year,” the company said.

While the overall reduction in deficiencies is a promising trend, it is also important to track how problems are solved and how quickly fixes are pushed to the rest of the fleet, said Dan Grazier, an analyst with the independent watchdog group Project on Government Oversight.

“I’m not surprised that they are continuing to find issues. This is why we are supposed to be testing weapon systems before we buy a whole bunch of them. I am a little surprised that we are finding CAT 1 deficiencies at this point during operational testing,” Grazier said.

“I think that speaks to the level of complexity with this program that it’s taken us this long to get to this point, and even after all the testing that has been done and the time and money that has gone into this that we’re still finding category 1 issues," he added. "It shows that the program wasn’t born in the right place. It was way too ambitious from the very beginning.”

Aside from four classified problems, there remain three open category 1 deficiencies in need of a fix. There are myriad reasons for that, the program office stated.

“Reasons for delayed issue closure vary according to the complexity of the solution and the availability of test assets needed to verify the solution,” the JPO said. “The U.S. services fund the F-35 program to address a prioritized set of DRs [deficiency reports], while at the same time, develop new capabilities. It is likely that some low-priority DRs will never be resolved because of their minor impact on F-35 fleet operations does not justify the cost of resolution."

The F-35 program office provided some details on the path forward for resolving these technical flaws, but noted that many details regarding those plans remain classified:

Spikes in the F-35 cockpit’s cabin pressure have been known to cause barotrauma, or extreme ear and sinus pain.
This problem was documented when two Air Force pilots, flying older versions of the F-35A conventional-takeoff-and-landing model, experienced ear and sinus pain that they described as “excruciating, causing loss of in-flight situational awareness, with effects lasting for months,” according to documents obtained by Defense News. The physiological event is known by the medical term barotrauma.

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Spikes in the F-35 cockpit’s cabin pressure have been known to cause extreme ear and sinus pain. (Senior Airman Danielle Charmichael/U.S. Air Force)

The F-35 Joint Program Office believes barotrauma in the jet is caused when sensors on the outer mold line of the aircraft detect “rapidly changing static pressures” that, in turn, drive very quick changes of the cockpit pressure regulator valve.

Lockheed Martin has tested a fix that proved to be successful in a laboratory setting, Lockheed program head Greg Ulmer said last year.

But flight testing of that improvement has not occurred, slowing the pace of a solution. The F-35 program office now says flight testing of a new cockpit pressure regulation system is planned for mid-2020. If all goes well, the deficiency should be completely eliminated in 2021.

On nights with little starlight, the night vision camera sometimes displays green striations that make it difficult for all F-35 variants to see the horizon or to land on ships.

On nights where there is little ambient light, horizontal green lines sometimes appear on the night vision camera feed, obscuring the horizon and making landing on a ship more dangerous.


The problem is different than the notorious “green glow” issue, caused when the F-35 helmet-mounted display’s LED lights produce a greenish luminescence that inhibits a pilot’s ability to land on an aircraft carrier on nights with very little light.

At one point, both Lockheed and the government’s program office believed both problems could be solved by the F-35 Generation III helmet that the U.S. military began fielding last year.
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The F-35 Gen III helmet features six external cameras as well as built-in night vision. (R. Nial Bradshaw/U.S. Air Force)

Although the program office no longer considers the “green glow” problem a deficiency, it appears that the new helmet did not completely solve the night vision camera issue. The program office told Defense News that it intends to develop software improvements and test them in flight later this year, but the deficiency will not be considered “closed” until at least 2021.

The sea search mode of the F-35’s radar only illuminates a small slice of the sea’s surface.
Unlike the other problems, which are the result of the contractor not meeting technical specifications or the jet not working as planned, this deficiency is on the books even though the jet’s Northrop Grumman-made AN/APG-81 active electronically scanned array radar fulfills its requirements.

Currently, the radar can only illuminate what is directly in front of it when in sea search mode. That performance is not good enough for the Navy, which wants to be able to search a wider area than is currently possible.

Although this problem can be fixed with software modifications and an upgrade to the radar’s processing power, it will continue to be on the books for some time. According to the program office, “[the] U.S. services agreed to plan for an improved radar mode, which will require the Technology Refresh-1 avionics update, for software release in [calendar year] 2024.”

‘A line in the sand’
Although Defense Department and military leaders have criticized the F-35 program for high operations and sustainment costs, the operational community has rallied around the performance of the jet, praising its advanced computing capability that allows the aircraft to mesh together data from different sensors and provide a more complete picture of enemy threats.

Brig. Gen. David Abba, who leads the Air Force’s F-35 integration office, said in March that he was comfortable with the path forward to correct open deficiencies, downplaying the impact of those issues on daily operations.

“Is it important to hold folks’ feet to the fire and make sure that we’re delivering on the capabilities that we need? Yes,” he said. But, he added, it’s also difficult to balance the need to meet a stated technical requirement against the reality of a fielded technology that may already be performing well in daily operations.

“That’s the crux of the acquisition and the delivery problem that we have,” Abba said. “When we say ‘I need this to work exactly like this,’ I’m drawing a line in the sand. If I’m a half degree on one side of that line versus the other, is it really that different? That’s where the art comes in.”

“We’ve got to kind of get over ourselves a little bit and acknowledge that we never field perfect weapon systems,” he continued. “I don’t want to diminish the fact that it’s critical that we get after open DRs, but every weapon system in the United States Air Force — and frankly around the planet — has open deficiencies. What matters is the severity of those deficiencies and ensuring that we have a robust process between government and industry to triage those and deal with them appropriately.”
 

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Lockheed Boasts Fixing Most, But Not All, of F-35’s Key Flaws Five Years After Jet's Introduction
11.05.2020

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Although it’s been touted for its advanced stealth capabilities, the F-35 programme has been attacked by everyone from US defence analysts to President Trump over its staggering $1.5 trillion+ lifetime price tag, single engine design and seemingly never-ending series of glitches and design flaws.

Lockheed Martin has boasted the successful elimination of critical bugs that could endanger pilots’ lives and about nine tenths of the other serious flaws threatening the planes’ mission capable status, Bloomberg has reported.
Jon Ludwigson, top F-35 analyst at the Government Accountability Office, the US government watchdog which found some 111 ‘Category 1’ issues (i.e. those that can injure or kill pilots or otherwise jeopardize the plane’s security) in 2018, told the business outlet that the Pentagon’s F-35 programme office has “done a good job at working” with the military “to really prioritize what needs to get fixed versus what would be just a helpful thing to the pilot – getting to the actual things they need to get at.”
Ludwigson also promised that the military and Lockheed “have procedures in place to work around” the issues that remain.
Eight ‘Category 1B’ bugs, designated as those that could present a “critical impact on mission readiness,” remain, with five expected to be fixed by Christmas. These issues include ear-damaging cabin pressure problems, obscured night-vision issues and a glitch which limits the plane’s capability to carry out search at sea operations using its radar. The latter issue isn’t expected to be resolved until 2024.
The F-35 is also said to still have 860 ‘less serious’ bugs, 85 percent of them said to be software-related, with the issues classified as yet to be fixed or verified as fixed. That number has actually grown from 855 in the GAO’s January 2018 report.
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The first F-35A Lightning II assigned to the 354th Fighter Wing lands at Eielson Air Force Base, Alaska, April 21, 2020. A total of 54 F-35As will be stationed at Eielson AFB by the end of 2021, which will make Alaska the most concentrated state for combat-coded fifth-generation aircraft

The F-35 programme has been on thin ice amid US officials’ search for wasteful Pentagon spending, with 100+ ‘Category 1’ flaws and hundreds of less serious flaws discovered in 2018, years after the planes began to be introduced into the services in 2015. In 2019, the GAO reported that just over a quarter of the F-35s already delivered were actually fully mission capable, citing lack of spare parts, breakdowns and unexpected problems, such as sensitivity to lightning strikes.

The latest fixes come ahead of plans by the Pentagon to determine next year whether the F-35 should continue to ramp up production to the potential 3,200 planes expected in total. To date, only about 520 of the planes have been delivered, and these will need to be refitted to fix the glitches and design flaws, a proposition that will require billions more in spending.

With an estimated lifetime price tag of a staggering $1.5+ trillion, the F-35 is easily the most expensive weapons project in history, and among the most controversial. Many of the plane’s design issues stem from the Pentagon’s attempts to create a one-size-fits-all fighter platform to replace its fourth-generation fighter designs. The US plans to buy over 2,600 F-35s for the Air Force, Navy and Marine Corps. Multiple US allies have also ordered the plane, including the UK, Australia, Israel, Italy, the Netherlands, Norway, South Korea and Japan. Turkey was unceremoniously booted out of the programme last year amid the spat over Ankara’s purchase of a Russian-made air defence system.
 

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Lockheed Marietta Team Delivers 500th F-35 Center Wing
May 13, 2020
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The Marietta F-35 Team marked a milestone on April 28, as the 500th Center Wing, or CW, was shipped to the F-35 Final Assembly line in Fort Worth, Texas. The Marietta F-35 team delivered its first CW in September 2011. The milestone CW will be incorporated into CF-55, an F-35C aircraft that will be delivered to the U.S. Navy at NAS Lemoore, California, in 2021.

The CW is a major structural component and represents nearly one third of the aircraft’s fuselage. The aircraft’s wings are attached to the CW during final assembly. Nearly all of the aircraft’s F135 engine case is enclosed in the CWA.

The Marietta team builds CWs for all three F-35 variants, the Conventional Takeoff and Landing (CTOL) F-35A, the Short Takeoff/Vertical Landing (STOVL) F-35B, and the Carrier Variant (CV) F-35C.

“What this team has accomplished since assembly began a decade ago and now reaching 500 Center Wings delivered is phenomenal,” said Caleb Hendrick, the Marietta F-35 program director. “The hallmarks of this team have been innovation, flexibility, spirit, and results – all aligned around the expectations of our customers. This team should be proud of the way it works together to support the Warfighters. I want to thank everyone for the job they have done and continue to do.”

Production has ramped up from five Center Wings delivered in 2011, to 21 in 2012 (the first full year of production), to 112 CWs in 2019. The Marietta team is currently scheduled to deliver more than 120 CWs in 2021.

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The 500th F-35 center wing on the production line at Lockheed Martin’s plant in Marietta, Georgia.

The time span between Center Wing deliveries has dropped from one CW about every 11 manufacturing days in the initial years of the program to one CW every 1.8 manufacturing days in 2020.

But in addition to reaching rate production, the team has saved an estimated $80 million from projected costs at the inception of the program to now. The innovations in the Marietta assembly line were designed to save millions over the life of the F-35 program. But, in just 500 units, the Marietta team has outpaced even those optimistic estimates that come close to the cost of an entire F-35 aircraft.

A key measurement is hours per unit—the amount of time required to build a Center Wing. The HPU to build CWs for an F-35A CTOL aircraft has improved from roughly 17,000 hours to about 5,000 HPU, beating the original targeted projections significantly.

The Marietta Team has also made reductions in HPU for the more complex F-35B STOVL and F-35C CV aircraft at nearly the same rate as for the F-35A CWs. The HPU for the F-35B CWs has been reduced from approximately 14,000 hours to 5,300 hours. The HPU for the F-35C aircraft has been reduced from roughly 16,000 hours to about 6,000 hours.

Approximately 450 people work directly on the F-35 program in Marietta. In addition to assembling the CWAs on a state-of-the art production line, technicians also apply specialized stealth coatings to the aircraft’s horizontal and vertical tail assemblies. The tails are shipped to Fort Worth and attached to the aircraft there. The Marietta team also coats spare and repaired doors, panels and covers for the F-35.
 

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Poland has signed a contract wotrh $4.6 billion under which the country will acquire 32 F-35A Lightnin II fighter jets from the USA. Speaking the the official signing ceremony on 31 Jan., Polish Defense Minister Mariusz Blaszczak siad that the acquisition will enable the Polish military to a thechnological leap. With signing the F-35 official the Polish AF is entering a new phase of its development.
 

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Poland has signed a contract wotrh $4.6 billion under which the country will acquire 32 F-35A Lightnin II fighter jets from the USA. Speaking the the official signing ceremony on 31 Jan., Polish Defense Minister Mariusz Blaszczak siad that the acquisition will enable the Polish military to a thechnological leap. With signing the F-35 official the Polish AF is entering a new phase of its development.
Any links?
 

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The inside story of two supersonic flights that changed how America operates the F-35

WASHINGTON — The F-35 pilot who flew the two infamous supersonic missions that inflicted damage to the jet’s stealth coating and tail wants to set the record straight.
When pilots conduct supersonic intercepts or find themselves needing to race away from an enemy during combat, they will be able to take the F-35 to its furthest limits of speed and altitude — most likely without any permanent damage to the aircraft, he told Defense News in an exclusive interview.
Last June, Defense News revealed that the Pentagon had instituted time limits on the number of seconds the F-35B short-takeoff-and-landing variant and the F-35C carrier variant could spend at supersonic speeds.

Those limits were imposed after two separate tests in 2011 where the "B" model incurred “bubbling [and] blistering” of its stealth coating and the "C" model suffered “thermal damage” to the tailboom and horizontal tail, according to documents exclusively obtained by Defense News.
But those limitations must be placed in context, said Billie Flynn, the Lockheed Martin test pilot who flew both of those missions during F-35 developmental testing at Naval Air Station Patuxent River in Maryland.

According to the documents, both incidents took place during flutter tests where the B and C models were flying at speeds of 1.3 Mach and 1.4 Mach. However, that damage didn’t occur in a vacuum, Flynn said. It materialized after F-35B and F-35C test articles flew repeated supersonic runs that pushed to the plane’s maximum of 1.6 Mach, making it the result of cumulative pressures on the aircraft.
“I was flying out at 700 knots in the C model up and down the East Coast of the state of Maryland and Delaware — that’s where we fly at Pax River — and then out over the ocean, firing missiles at almost 1.6 Mach as we cleared out the weapons for the airplane. That’s extreme speed, and that’s repeated flights in those environments,” said Flynn, who has flown more than 800 hours in all three F-35 variants.
“Make a run at 700 knots, make another run at 700 knots, go to an aerial refueling tanker, get fuel for myself … and then race out again and again and again. Repeat this cycle for four- and five-hour missions,” he added.
Similarly, the flights for the B model involved aggressive maneuvering at the edge of the aircraft’s flight envelope for hours at a time.

“Nobody is going to do [that] tactically,” he said. “There’s not a combat scenario where that is going to happen.”


Instead, Flynn offered the possibility that the degradation was only visible to engineers monitoring the internal impacts to the F-35B and F-35C test planes, which are specially equipped to measure imperceptible damage to the jet’s structure and give insight into how forces such as gravity and heat will affect it over time.
“I don’t know if I really ever saw much after a flight. I just knew that our engineers had told us about [the problem],” he said. “So an engineer whose specialty is structures would see that it would be hotter than they predicted, which would lead them to tell us: ‘If this airplane is going to last 40 years long, then we have to manage this exposure.’ ”
An operational context
When Defense News first reported on the F-35’s limits on supersonic speeds in 2019, they were classified by the Pentagon as two separate category 1 deficiencies, representing the most serious type of technical issue.

The Defense Department considers the issue “closed” as of December 2019 despite no plan to correct the problem. The F-35 Joint Program Office explained that “the operator value provided by a complete fix does not justify the estimated cost of that fix.”
Still, the documents obtained by Defense News stated that F-35C supersonic intercept missions may be impossible. Simulator testing showed that restricting supersonic flight at full afterburner to a maximum of 50 seconds could prevent the C model from reaching the 1.44 Mach endpoint for weapon launches, according to the F-35 integrated test team at Patuxent River.
To cut down the risk of damage to the jet, the Pentagon imposed time limits on how long F-35B and F-35C pilots can spend at supersonic speeds in full afterburner. An F-35C can only fly at Mach 1.3 in afterburner for 50 cumulative seconds, meaning that a pilot cannot clock 50 seconds at that speed, slow down for a couple seconds and then speed back up. The F-35B can fly for 80 cumulative seconds at Mach 1.2 or for 40 seconds at Mach 1.3 without risking damage.
The time requirements reset after the pilot operates at military power — an engine power setting that allows for less speed and thrust than afterburner — for a duration of three minutes.
By abiding by those time restrictions, the U.S. military ensures the F-35 lasts the entirety of its planned service life and that the fleet isn’t overly taxed during normal training and operations, Flynn said.

But in wartime, Flynn said, pilots will do whatever is needed “to survive and to be effective” — even if that means disregarding time restrictions and pushing the plane to its maximum performance.

Supersonic flight is not a major feature baked into F-35 tactics, the capability would likely only be used in cases when it is absolutely necessary to intercept another aircraft or in emergency situations, said Bryan Clark, an analyst with the Hudson Institute and a retired naval officer.
“It’s capable of it,” he told Defense News in April, “but when you talk to F-35 pilots, they’ll say they’d fly supersonic in such limited times and cases that — while having the ability is nice because you never know when you are going to need to run away from something very fast — it’s just not a main feature for their tactics.”
In fact, flying at supersonic speeds could minimize one of its greatest features — stealth — particularly if the jet were to do it for a long time, Clark said.
“It takes you out of stealthiness, it burns gas like crazy, so you lose the range benefits of a single engine and larger fuel tank. When you go into afterburner, you are heating up the outside of your aircraft,” he explained.
The stealthy F-35 is supposed to be able to penetrate into contested areas and destroy foes without detection, but naval aviation has little experience with low-observable aircraft and has a historical distrust of relying on long-range kills. When told about the deficiencies last year, one retired naval aviator expressed concern about the ability of F-35 pilots to move safely out of a contested area.
“The solution is: ‘Hey, we’ll just limit the afterburner to less than a minute at a time,’ ” the naval aviator told Defense News. “Which, with what the aircraft is supposed to do and be capable of, that’s a pretty significant limitation.”
But fifth-generation jets like the F-35 shouldn’t be playing by fourth-generation rules, said Flynn. In other words, the F-35 doesn’t have to rely on supersonic speed to penetrate a contested area the way most legacy jets do.
“Let’s get away from the legacy mindset. We’re an aircraft that operates with impunity. We’re an aircraft that is [a low-observable] platform that operates different than every legacy platform," he said.
“The notion that you have to stay away from someone, or you have to run someone down [because] they see you, is the wrong context for a fifth-generation fighter but is entirely the issue for a legacy [F-14] Tomcat, [F/A-18] Hornet, [F-16] Viper, [Eurofighter] Typhoon.”
David B. Larter contributed to this report.
 

mtime7

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the story I posted right above has got me thinking, the F-35A (the Air Force version) doesn't seem to have this problem and they ok'ed for as much afterburner as they want, did the test pilot of the A model just not flog the plane as hard, cause this guy sounds like he was really giving the B and C model hell.
 

Aadi

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The Pentagon will have to live with limits on F-35’s supersonic flights

View attachment 12360
The first F-35C Lightning II sortie takes off from the U.S. Navy F-35 Strike Fighter Squadron VFA 101 at Eglin Air Force Base, Fla. A design issues means the Navy's and Marine Corps' F-35 versions will have some limits on supersonic flights. (Samuel King Jr./U.S. Air Force)

WASHINGTON — An issue that risks damage to the F-35’s tail section if the aircraft needs to maintain supersonic speeds is not worth fixing and will instead be addressed by changing the operating parameters, the F-35 Joint Program Office told Defense News in a statement Friday.

The deficiency, first reported by Defense News in 2019, means that at extremely high altitudes, the U.S. Navy’s and Marine Corps’ versions of the F-35 jet can only fly at supersonic speeds for short bursts of time before there is a risk of structural damage and loss of stealth capability.

The problem may make it impossible for the Navy’s F-35C to conduct supersonic intercepts.

“This issue was closed on December 17, 2019 with no further actions and concurrence from the U.S. services,” the F-35 JPO statement read. “The [deficiency report] was closed under the category of ‘no plan to correct,’ which is used by the F-35 team when the operator value provided by a complete fix does not justify the estimated cost of that fix.

“In this case, the solution would require a lengthy development and flight testing of a material coating that can tolerate the flight environment for unlimited time while satisfying the weight and other requirements of a control surface. Instead, the issue is being addressed procedurally by imposing a time limit on high-speed flight.”

The carrier-launched "C" variant and the short-takeoff-and-vertical-landing "B" version will both be able to carry out all their missions without correcting the deficiency, the JPO said.

The potential damage from sustained high speeds would influence not only the F-35’s airframe and the low-observable coating that keeps it stealthy, but also the myriad antennas located on the back of the plane that are currently vulnerable to damage, according to documents exclusively obtained by Defense News

The JPO had classified the issues for the "B" and "C" models as separate category 1 deficiencies, indicating in one document that the problem presents a challenge to accomplishing one of the key missions of the fighter jet. In this scale, category 1 represents the most serious type of deficiency.

While it may seem dire that an aircraft procured for flying at supersonic speeds will be unable to do so for extended periods, the F-35 may not need to do it that often.

For the F-35, as opposed to the F-22 where supersonic flight is baked into its tactics, the ability to fly supersonic is more of a “break glass in case of emergency” feature, said Bryan Clark, an analyst with the Hudson Institute and a retired naval officer.

“Supersonic flight is not a big feature of the F-35,” Clark said. “It’s capable of it, but when you talk to F-35 pilots, they’ll say they’d fly supersonic in such limited times and cases that — while having the ability is nice because you never know when you are going to need to run away from something very fast — it’s just not a main feature for their tactics.”

In fact, going supersonic obviates the main advantages of the F-35, Clark said. “It sort of defeats all the main advantages of the F-35,” he explained. “It takes you out of stealthiness, it burns gas like crazy so you lose the range benefits of a single engine and larger fuel tank. When you go into afterburner, you are heating up the outside of your aircraft.”

That creates all kinds of signatures that can be detected by an adversary, Clark said.

What if?
But a retired naval aviator told Defense News last year that the limitations on the afterburner could prove deadly in close-combat scenarios.

The concept of operations for the F-35 is to kill an enemy aircraft before it can detect the fighter jet, but relying on long-range kills is a perspective that, for historical and cultural reasons, naval aviation distrusts. In the Vietnam War, when air warfare began heavily relying on missiles and moved away from the forward gun, it caused a spike in air-to-air combat deaths.

The lesson naval aviation took away was to prevent the latest and greatest technology from offsetting the learning of fundamentals, and it was the impetus behind the formation of Top Gun 50 years ago, a naval strike fighter course for training and tactics development.

“The solution is: ‘Hey, we’ll just limit the afterburner to less than a minute at a time,’ ” a retired naval aviator said when told of the issue. “Which, with what the aircraft is supposed to do and be capable of, that’s a pretty significant limitation.”

Primarily it would be an issue if the aircraft had to maneuver at high speeds to avoid a missile or survive a dogfight.



The issue is compounded for the Navy, which must operate forward for months at a time, because any significant issues with coatings or the structure of aircraft would require a depot-level repair. And so a damaged aircraft would remain damaged until its host ship returns to home port, reducing the combat effectiveness of the air wing.

“We might have to be operating at sea for eight months, so if you damage something on week one, guess what? It’s damaged for the rest of the deployment,” the aviator said. “And it affects your ability to evade detection by the enemy — you just degraded that asset permanently until you can get it somewhere where it can be fixed, at great expense and time.”

Other deficiencies

Three other category 1 deficiencies have also been officially designated as “closed," meaning they have either been fixed or the performance of the aircraft is being accepted as is, the JPO reported.

The so-called green glow deficiency has been closed out as of last July. Green glow refers to a green light emitted by the helmet-mounted display’s LED lights. That glow obstructs a pilot’s view of an aircraft carrier’s deck lights during landing operations at sea in very low light, such as that experienced at night.

The issue was closed “as a result of incorporating an improved Organic Light-Emitting Diode (OLED) Helmet Mounted Display (HMD),” the JPO told Defense News.

“The Generation III F-35 OLED Helmet Display Unit (HDU) significantly reduced the ‘green glow’ experienced by pilots during night operations. The F-35 JPO has taken delivery of the first order of F-35 OLED HDUs to support the U.S. Navy (USN) and U.S. Marine Corps (USMC), and a second order of OLED HDUs has been placed,” the office’s statement read.

An issue created when the F-35A and F-35B blow a tire, which can result in a severed hydraulic line, will remain uncorrected, the JPO statement said, but it has not come up again since the program switched tires.

“The DR [deficiency report] was closed under the category of ‘no plan to correct’ based on the fact that the landing gear system design meets all F-35 safety standards,” the statement read. “Issues related to premature bursting of tires were resolved by tire design changes during early F-35 development and no instances of dual hydraulic system loss caused by a tire burst have ever been observed on an F-35.”

And an issue that forced the F-35 to land in cold weather because of battery trouble has been fixed, the JPO said. The issue was caused by extreme cold entering the plane when the doors to the jet’s nose landing gear were open, setting off alarm bells, according to “for official use only” documents exclusively obtained by Defense News.

The cold would enter the plane and overwhelm the battery heater blanket, which is installed to keep a 28-volt battery running at peak condition. The battery would not shut down, but because of the cold, the blanket could not heat the battery as quickly as intended, triggering warning lights in the cockpit that the battery was going to fail.

A software upgrade fixed the problem, the JPO said.

“This issue was resolved on July 22, 2019 due to improvements in the battery charger’s firmware,” the statement read. “The firmware changes were developed by the battery charger supplier, and integrated and tested by Lockheed Martin and the F-35 Lightning II Joint Program Office.”
what a beautiful machine
 

Khafee

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the story I posted right above has got me thinking, the F-35A (the Air Force version) doesn't seem to have this problem and they ok'ed for as much afterburner as they want, did the test pilot of the A model just not flog the plane as hard, cause this guy sounds like he was really giving the B and C model hell.
I was thinking the same thing. Why no issues with the "A" model? To me it seems what you said, above in red.
 

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is a multipurpose single-seat fighter of 5th generation, single-engine, with trapezoidal wing with stealth characteristics, used by the Italian air force in recent years has some scary features a perfect machine for any type of stealth mission, very very nice ;)
 

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P&W Outlines New Plan for F-35 Engine Upgrades
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Pratt & Whitney has changed its proposed upgrade path for the F135 engine powering the F-35 Lightning II stealth fighter. It is now offering two stages of improvements over a four-year period, compared with the three-stage, 10-year plan ending with a completely new engine that it revealed a year ago. The stages are labeled Growth Option 1.0 and 2.0 and include greater thrust, lower fuel burn, and better thermal management.

Matthew Bromberg, president of P&W Military Engines, told AIN that since last year, P&W has combined the informally labeled “Growth 1A” thrust-increase option for the F-35B STOVL version within the overall Growth Option 1.0 package. This package offers 10 percent more thrust than the F135’s current nominal 40,000 pounds and 5 percent better fuel burn. But for the F-35B, P&W is working with Rolls-Royce to also provide a 5 percent increase in vertical thrust during the hover.

P&W previously described Growth Option 2.0 as an all-new production engine that would result from its adaptive-cycle research and development under the U.S. Air Force Research Laboratory Advanced Engine Transition Program (AETP). Both General Electric and P&W are working on engineering, manufacturing, and development (EMD) contracts from the Pentagon for the AETP, which could power a sixth-generation fighter aircraft.

However, Bromberg said that Growth Option 2.0 for the F135 could now provide the F-35 with “a significant increase in power and thermal management capability” within four years, rather than being a completely new engine design, which might not be available until a decade hence.

P&W is offering the new optional package as a result of the perceived need for an improved power and thermal management system (PTMS) to accompany the upgrades to the F-35 that Lockheed Martin is proposing. Lockheed Martin describes these as a continuous capability development and delivery (C2D2) strategy, but some are also known as the Block 4 upgrade. The upgrade program is scheduled to begin next year but is still under negotiation by the F-35 Joint Program Office.


The Growth Option 2.0 upgrades will result from P&W’s adaptive-cycle R&D effort focusing on third-airstream capability, adaptive-cycle controls, and new materials, with the company planning to “take the technologies as they mature and insert them into existing engines,” said Bromberg. “It’s a whole suite of technologies; we will look at everything. We’re leveraging the bleed systems, the integration system, and the control system.” In addition to the adaptive-cycle fan’s third airstream, P&W is also “looking at adaptive elements in the controls, the components, and the core,” he said.
The result will be a Growth Option 2.0 development strategy that will offer “low-risk EMD” and which “does not add to the four-year Growth Option 1.0 EMD program at all,” said Bromberg. “We are just adding the PTMS requirements into [the] Growth Option 1.0 [development timeline] to meet all the C2D2 requirements.” In fact, he added, once launched, the Growth Option 2.0 EMD program will be even less than four years if customers “look only at sub-options.”
Describing the Growth Option 2.0 upgrades as “a menu of options under the adaptive umbrella,” he confirmed P&W will tailor the package to each customer’s requirements for particular PTMS enhancements. Bromberg said the company will make all the optional Growth Option 2.0 upgrades available to international customers for the F-35, as well as to the aircraft’s U.S. operators.
 

mtime7

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Not sure if anyone is interested, but in the new Defense Bill it says that Turkey's F-35's are going to the US Air Force. There is apparently 5 in storage
 

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Not sure if anyone is interested, but in the new Defense Bill it says that Turkey's F-35's are going to the US Air Force. There is apparently 5 in storage
US Air Force to keep six F-35 jets sold to Turkey

To play off of the famous line from the “Soup Nazi” of Seinfeld fame, “No F-35 for you.”

NATO’s arguably worst partner state has been denied the F-35 by the United States, and the move comes as both expensive and advantageous for US aerospace mogul Lockheed Martin.

Six multirole aircraft were earmarked for Turkey, but the Eurasian nation’s purchase of Russian S-400 missile systems effectively made sure that the aircraft would never make it to their final destination.

According to Ekathimerini, the US Senate Armed Services Committee said on Thursday it had authorized $9.1 billion to obtain the F-35s alongside an existing order.

It is unknown which branch the Turkish F-35s will go to, though it is likely that they will be brought into the US Air Force’s inventory due to them lacking the more Navy and Marine Corps-friendly features.

The ninety-five F-35s already being procured will actually exceed the United States’ desired (budgetary) number by fourteen, and the six that were supposed to go to Turkey will likely require some exchanges in avionics and other “export” features to bring the aircraft up to spec.
 

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