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What is up with the F-35? Part II

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  • Compared to the most advanced supercar manufacturers (Mcclaren/Ferrari/Lamborgini) how far ahead is the technology used in the construction of the F35's body?

    Ignoring stealth etc are we talking 10 years til the car builders get it or 20 or is pretty much on par?

    Comment


    • Originally posted by Gun Boat View Post
      Compared to the most advanced supercar manufacturers (Mcclaren/Ferrari/Lamborgini) how far ahead is the technology used in the construction of the F35's body?

      Ignoring stealth etc are we talking 10 years til the car builders get it or 20 or is pretty much on par?
      I can only give an answer on hearsay.

      I have heard that what former aircraft engineers particularly like about working in formula 1 is that new ideas are implemented very quickly, without a lengthy approval process.

      I wouldn't be too surprised if the car manufacturers would be ahead on some technologies.

      Comment


      • Originally posted by FJV View Post
        I can only give an answer on hearsay.

        I have heard that what former aircraft engineers particularly like about working in formula 1 is that new ideas are implemented very quickly, without a lengthy approval process.

        I wouldn't be too surprised if the car manufacturers would be ahead on some technologies.
        It's probably like building an f1 car but with 10x the complexity and 10X the testing and evaluation. Another way of thinking about it is that each wing is about similar build complexity as an f1 car.

        Comment


        • Originally posted by Gun Boat View Post
          Compared to the most advanced supercar manufacturers (Mcclaren/Ferrari/Lamborgini) how far ahead is the technology used in the construction of the F35's body?

          Ignoring stealth etc are we talking 10 years til the car builders get it or 20 or is pretty much on par?
          I think the biggest difference in trying new things with aircraft is the penalty for failure.

          Testing a new material or manufacturing technique in a prototype car is relatively safe. If something goes wrong, the car rolls (or skids) to a stop and you investigate to figure out why it didn't work as expected.

          If the new material or technique fails on a fighter, there is a pretty good chance you lose the pilot as well as the prototype. Not to mention the difficulty in determining what exactly went wrong after the fighter smacks into the ground and leaves you a pile of smoking metal to sift through.
          Last edited by SteveDaPirate; 12 Mar 15,, 15:54.

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          • The F35s and other US platforms may get an engine upgrade in the 2020s that will give them 25% more range with more engine thrust:



            The ADVENT program was recently completed successfully. The follow up ADET program will begin in 2016.

            GE Details Sixth-Generation Adaptive Fighter Engine Plan | Defense content from Aviation Week

            U.S. military planners have now broadly accepted that the only way to meet the advanced performance needs of “sixth-generation” combat aircraft, barring changes to the laws of physics, will be the adoption of variable-cycle, or adaptive engine, technology.

            The future fighter will be required to not only fly farther than today’s aircraft, but will also need more speed and power when engaging the enemy. But from a propulsion perspective, up until now these objectives have been mutually exclusive. Longer range and subsonic loiter require lower fuel burn and good cruise efficiency, while higher thrust for supersonic dash demands larger cores and much higher operating temperatures, neither of which is good for fuel burn or stealth.

            To solve this conundrum and combine both capabilities in one propulsion system, engine makers are working under the U.S. Air Force Research Laboratory’s (AFRL) Adaptive Engine Technology Development (AETD) program to test technology for a new generation of engines that can be reconfigured in flight. Although AETD is set to end with a flight-weight core demonstration in 2016, the Air Force is planning a follow-on initiative called the Adaptive Engine Transfer Program (AETP). This will pave the way for an adaptive, 45,000-lb.-thrust-class combat powerplant for sixth-generation combat aircraft as well as the possible reengining of the Lockheed Martin F-35 in the 2020s.
            Adaptable engines use an array of variable geometry devices to dynamically alter the fan pressure ratio and overall bypass ratio—the two key factors influencing specific fuel consumption and thrust. Fan pressure ratio is changed by using an adaptive, multistage fan. This increases the fan pressure ratio to fighter-engine performance levels during takeoff and acceleration, and in cruise lowers it to airliner-like levels for improved fuel efficiency.

            To alter bypass ratio, variable-cycle engines add a third airflow stream outside of both the standard bypass duct and core. The third stream provides an extra source of airflow that, depending on the phase of the mission, can be adapted to provide either additional mass flow for increased propulsive efficiency and lower fuel burn, or to provide additional core flow for higher thrust and cooling air for the hot section of the engine, as well as to cool fuel, which provides a heat sink for aircraft systems. During cruise, the third stream can also swallow excess air damming up around the inlet, improving flow holding and reducing spillage drag.
            The Advent turbofan test was “extremely successful,” but also revealed some unexpected and highly relevant information. “One of the things we found with adaptive engines is that modeling techniques for understanding the performance of adaptive cycles is well-tuned, but modeling adaptive three-stream engines is a little different. Some of it we got right and some of it [we have to reexamine]. The turbofan engine has been an extremely valuable tool for us,” notes McCormick.

            Advent broke ground for the subsequent AETD effort, for which GE and Pratt were selected over Rolls in 2012. The program is aimed at technology for a new combat-aircraft engine with 25% lower thrust-specific fuel consumption, but 5% more military power and 10% higher maximum thrust than Pratt’s F135. AETD therefore goes beyond Advent in terms of efficiency and power, and unlike the smaller cores used in the initial effort, which were aimed at B-2 bomber-type power ranges, is based around a larger core.
            One of the greatest areas of advance, which GE believes to be a major trump card in the sixth-generation engine contest, is the extensive application of lightweight, heat-resistant ceramic matrix composite (CMC) materials. “The F136 had one part made of CMCs, the third-stage nozzle. Now CMCs [are] all the way back through the hot section from the combustor to the low-pressure turbine, including rotating parts,” says McCormick. The pioneering application of CMCs on a rotating stage was successfully tested on an F414 in late 2014 (see sidebar).
            Last edited by citanon; 30 Mar 15,, 17:10.

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            • Didn't GE already do this with their F-120, the engine that ended up losing to P&W's F-119 for the Raptor contract? IIRC, the Air Force didn't like the fact that it was an emerging technology, and elected to stay with the tried & proven low-bypass ratio turbofan technology of the PWF-119; there were already enough ground-breaking technologies on the F-22 at the time (the '90's), they didn't want to add an engine to the (long) list.
              "There is never enough time to do or say all the things that we would wish. The thing is to try to do as much as you can in the time that you have. Remember Scrooge, time is short, and suddenly, you're not there any more." -Ghost of Christmas Present, Scrooge

              Comment


              • Why the Marine Corps Is Rushing to Deploy an Imperfect Combat Aircraft

                By Sandra I. Erwin


                Why the Marine Corps Is Rushing to Deploy an Imperfect Combat Aircraft - Blog

                The biggest story this year so far in the F-35 joint strike fighter world is not the soaring cost of the aircraft — a problem that appears to have been contained, according to the program manager — but the determination of the Marine Corps to put the aircraft into service even though its mission software is unfinished and cracks surfaced in one of its main bulkheads.

                None of these issues is serious enough to deter the Marine Corps from declaring the F-35B — the short-takeoff vertical landing version of the joint strike fighter — ready for combat use. Marines insist that they would much rather take an incomplete F-35B than continue to fly their antiquated fighters.

                The F-35B would eventually replace all AV-8B Harriers, F/A-18 Hornets and the EA-6B Prowlers. One of the shortfalls in the new airplane is that its mission software, called Block 2B, is still not able to perform “sensor fusion” functions that allow pilots to identify targets and share the data across a network of multiple F-35s. Fusion is one of the attributes that distinguish “fifth generation” fighters like the F-35 from older models developed during the Cold War.

                The Marine Corps intends to start flying the F-35B in combat duties some time in July, a milestone called “initial operational capability,” or IOC. This move has been criticized by Pentagon weapon testers who frown on military programs that rush to meet self-imposed deadlines. The Defense Department’s Director of Operational Test and Evaluation J. Michael Gilmore cautioned in his 2014 annual report that the F-35B mission software will be delivered with "troubling capability shortfalls."

                The full-blown F-35 mission software would not come until 2017, but the Marine Corps is looking at this in perspective: A less-than-optimum F-35B is still far more desirable than what they have now.
                “The Block 2B software configuration that the Marine Corps will IOC with brings an immediate increase in combat capability compared to legacy aircraft,” said Marine Corps spokesman Maj. Paul Greenberg. “Most of the deficiencies we track are deficiencies when compared to the F-35's full combat capability in 2017.”

                What matters, he said, is whether the aircraft can meet the basic needs of Marines at war, he said. In its current state, the F-35B can launch missiles, engage other aircraft in dogfights and drop bombs. “At IOC the F-35 will be able to target in real time, talk to forward air controllers over the radio and data-link, put weapons on target and do all of that in contested environments and in bad weather,” Greenberg said. The electronic attack features of the current F-35B, he added, represent a “transformation in electronic warfare spectrum management, and this is not possible with legacy aircraft.”

                The officer who oversees the F-35 program on behalf of the Marine Corps, Navy and Air Force said he is not bothered by the Marines’ decision to declare IOC much earlier than the other services. The Air Force is aiming for 2016 IOC and the Navy is eyeing 2019.

                “It's their call, and I support them on this,” said Air Force Lt. Gen. Christopher Bogdan, the program executive officer.

                Bogdan said the Block 2B software development was finished in February — four months after its original October 2014 deadline — but there are still glitches to be fixed over the course of this year. The next version, Block 3i for the Air Force, is scheduled for completion in 2016, and the one the Navy is waiting for, Block 3F, would be ready in 2018. F-35 prime contractor Lockheed Martin stands to lose $300 million in incentive fees if those deadlines aren’t met.

                The software that will be delivered to the Marines in June is “good enough for IOC” and the Marines understand its limitations, Bogdan said March 24 during a meeting with reporters.

                Software in general “always has been the number-one technical issue on this program. And always will be,” Bogdan said. The highly computerized aircraft runs on eight million lines of code. Much of that software manages the basic functions of the aircraft, such as flight controls, valves, fuel systems and radars. That software is working as intended, or the airplane would be unsafe to fly. The issues are with the so-called “fusion engine” that was designed to create a unified picture of the potential threats in the airspace so multiple F-35s can fight as a single information network.

                The fusion engine combines the input from the F-35 sensors — radar, electro-optical targeting system and distributed aperture system — to create a single track on the location of enemy targets in the air and on the ground. The data then is shared across the network. The software today cannot display accurate data to more than two aircraft at a time. “Fusion is by far the most complicated and, in my mind, worrisome element of this program,” Bogdan said.

                When four F-35s flew during a test exercise in recent months, the fusion engine created a confusing and inaccurate picture. Instead of identifying an air-defense missile battery on the ground, the software would “see” double or misread the location. “What we found is that when you have more than one F-35 looking at the same threat, they don't all see it the same,” Bogdan said. “When there's a slight difference, the fusion model can't decide if it's one or more threats.”
                The fusion algorithms have to be tweaked, and that could take months. “This is not something you can test in a lab,” Bogdan said.

                Marines are not losing sleep over this, at least not for now. They have come up with “workarounds” so they can use the F-35B in close-air support and air-to-air combat missions. “There are ways in which, with the software we have, pilots can work around those problems,” Bogdan said. One option is to only use certain sensors and turn off others. Targeting data would have to be acquired individually by each pilot instead of sharing it across the network. Pilot workload would increase.

                Bogdan insisted that the glitches will be fixed, but he would back the Marines if they chose to delay IOC between now and July. “The aircraft will be able to do everything the Marine Corps needs it to do for IOC, it just require pilots to do workarounds.”

                With just three months to go before IOC, there are other unresolved issues that Marines hope will be handled on time.

                One is simply having enough production-quality airplanes to equip the first Marine Corps operational squadron MFA-121 based in Yuma, Arizona. To date, only two of the required 10 aircraft have been equipped for combat. The Marine Corps currently owns a total of 32 F-35Bs but most are test aircraft so they would not be suitable for combat.

                Training also is a concern. Pilots need time to train in simulators that must have the same software as IOC airplanes. The simulators are expected to receive upgraded software over the next six weeks, Bogdan said. “We think we'll be ok.” Another requirement for IOC planes is to have files uploaded to its computers containing important data about global threats. The “mission data files” are in the works at Air Force Air Combat Command, in Langley, Virginia. “They'll get there in July, but it's really tight,” said Bogdan.

                Marines also will need to rush their aircraft technicians through training on the F-35 maintenance system, known as ALIS, or autonomic logistics information system. The system is not yet mature and it has to be shrunk in size to make it more transportable. “We squeezed racks into a two-man deployable ALIS,” Bogdan said. “The software had to be modified.” Maintainers have to start training 90 days in advance of IOC, and ALIS will miss that deadline by about a month. To make up the time, Marine maintainers at Yuma will spend several weeks at Lockheed Martin’s facility in Orlando, Florida, where there is a prototype ALIS system for them to train.

                “We know how to do ALIS. It's just going to take us a lot longer than we thought,” Bogdan said.

                On aircraft reliability — a measure of how long airplanes fly before they need repairs — the Marine Corps B model is the worst of the three. “The A and C models today are very close to where they're supposed to be,” Bogdan said. “We still got some work to do on the B model.”

                A potentially troubling flaw in the F-35B is in the structure, although Bogdan believes it is manageable. “I'm worried about bulkhead cracks on the B model,” he said. Based on test results, cracks develop after 4,000 to 5,000 hours of flight. The airplanes the Marines would fly this year only have a few hundred hours on them, so they would not be at risk, Bodgan said. The fact that cracks were found is not necessarily bad news, he added. “If you didn't have cracks, you didn't set up your test right. You want to know where the airplanes will break first.”

                The Marine version has problems stemming from a major redesign of the airframe started in 2005 after it was determined the airplane was 3,000 pounds overweight. Five titanium bulkheads — including the major load-bearing structure in the center of the fuselage — were replaced with lighter aluminum components. “Some of that, unfortunately, is coming back to bite us now,” Bogdan said. “What we thought was a good engineering judgment back then, now we have issues.” There will be modifications to the airplane to address this problem, and the entire fleet eventually will have to be retrofitted.

                Another hiccup in the F-35B have been the tires. An aircraft that takes off from short runways and lands vertically requires tires with enough bounce but also must be sufficiently rugged to maintain their form in 170 mph takeoffs. “We have been working hard to find the right balance between float and durability for vertical takeoff,” Bogdan said. “Our fourth tire is now in test. It appears to be working better than any of the others.” Tire manufacturer Dunlop has had difficulties producing the correct specs, he added, “But we’re moving in the right direction.”

                Amid these technical setbacks, the Marines can at least breathe a sigh of relief that the cost of the F-35B is finally coming down. Between production lots 6 and 8 over the past two years, Bogdan said, the price of the B model has slipped from $145 million to $134 million. In its unofficial “wish list” sent to Congress, the Marine Corps requested $1 billion for six additional F-35Bs. The budget request for fiscal year 2016 includes funding for nine aircraft.

                Marine officials recently have somewhat softened their stance on a July IOC, suggesting that it is not a hard deadline.

                “We won't declare IOC unless we meet all of our targets,” Lt. Gen. Jon Davis, deputy commandant of the Marine Corps for aviation told the Senate Armed Services Committee March 25.

                The F-35B with the current software provides “tremendous capability that we don't have today,” Davis insisted. “I have no fusion in the airplanes I operate today.” The pilots who fly it today “love the F-35B and they wouldn't go back to their original platforms.”

                On the software, Davis said he would withhold judgment for now. If the squadron is not ready to declare IOC, he said, the Marine Corps will respect that. “The decision to declare IOC will be event-based and conditions-based, based on us achieving what we have to do to deliver a combat capability to our Marines,” he said. “If conditions are met, I will make a recommendation to [Commandant] General Dunford that we declare our IOC.”

                Comment


                • Originally posted by Stitch View Post
                  Didn't GE already do this with their F-120, the engine that ended up losing to P&W's F-119 for the Raptor contract? IIRC, the Air Force didn't like the fact that it was an emerging technology, and elected to stay with the tried & proven low-bypass ratio turbofan technology of the PWF-119; there were already enough ground-breaking technologies on the F-22 at the time (the '90's), they didn't want to add an engine to the (long) list.
                  That's interesting, I didn't know that. Apparently the recent ADVENT program demonstration was very successful though. They had a running engine working within predictions on the ground.

                  Comment


                  • F-35 Tested Against F-16 In Basic Fighter Maneuvers | Defense content from Aviation Week

                    F-35 Flies Against F-16 In Basic Fighter Maneuvers
                    Apr 2, 2015 Guy Norris and Amy Butler Aviation Week & Space Technology

                    The F-35 Joint Strike Fighter has been flown in air-to-air combat maneuvers against F-16s for the first time and, based on the results of these and earlier flight-envelope evaluations, test pilots say the aircraft can be cleared for greater agility as a growth option.

                    Although the F-35 is designed primarily for attack rather than air combat, U.S. Air Force and Lockheed Martin test pilots say the availability of potential margin for additional maneuverability is a testament to the aircraft’s recently proven overall handling qualities and basic flying performance. “The door is open to provide a little more maneuverability,” says Lockheed Martin F-35 site lead test pilot David “Doc” Nelson.

                    The operational maneuvers were flown by Nelson in AF-2, the primary Flight Sciences loads and flutter evaluation aircraft, and one of nine F-35s used by the Edwards AFB-based 412th Test Wing for developmental testing (DT). The F-35 Integrated Test Force at Edwards has six F-35As, two F-35Bs and a single F-35C dedicated to DT work, as well as a further set of aircraft allotted to the Joint Operational Test Team. Work is underway as part of efforts to clear the final system development and demonstration (SDD) maneuvering envelopes on the way to initial operational capability (IOC). The U.S. Marine Corps F-35B IOC is targeted for later this year, the Air Force’s F-35A in 2016, and the U.S. Navy’s F-35C in 2019.

                    “When we did the first dogfight in January, they said, ‘you have no limits,’” says Nelson. “It was loads monitoring, so they could tell if we ever broke something. It was a confidence builder for the rest of the fleet because there is no real difference structurally between AF-2 and the rest of the airplanes.” AF-2 was the first F-35 to be flown to 9g+ and -3g, and to roll at design-load factor. The aircraft, which was also the first Joint Strike Fighter to be intentionally flown in significant airframe buffet at all angles of attack, was calibrated for inflight loads measurements prior to ferrying to Edwards in 2010.

                    The operational maneuver tests were conducted to see “how it would look like against an F-16 in the airspace,” says Col. Rod “Trash” Cregier, F-35 program director. “It was an early look at any control laws that may need to be tweaked to enable it to fly better in future. You can definitely tweak it—that’s the option.”

                    “Pilots really like maneuverability, and the fact that the aircraft recovers so well from a departure allows us to say [to the designers of the flight control system laws], ‘you don’t have to clamp down so tight,’” says Nelson. Departure resistance was proven during high angle-of-attack (AOA) testing, which began in late 2012 with the aircraft pushing the nose to its production AOA limit of 50 deg. Subsequent AOA testing has pushed the aircraft beyond both the positive and negative maximum command limits, including intentionally putting the aircraft out of control in several configurations ranging from “clean” wings to tests with open weapons-bay doors. Testing eventually pushed the F-35 to a maximum of 110 deg. AOA.

                    [ATTACH=CONFIG]39560[/ATTACH]
                    High angle-of-attack testing included intentional departures with weapons bay doors open. Credit: U.S. Air Force

                    An “aggressive and unique” approach has been taken to the high AOA, or “high alpha” testing, says Nelson. “Normally, test programs will inch up on max alpha, and on the F-22 it took us 3-4 months to get to max alpha. On this jet, we did it in four days. We put a spin chute on the back, which is normal for this sort of program, and then we put the airplane out of control and took our hands off the controls to see if it came back. We actually tweaked the flight control system with an onboard flight test aid to allow it to go out of control, because it wouldn’t by itself. Then we drove the center of gravity back and made it the worst-case configuration on the outside with weapons bay doors and put the aircraft in a spin.” The aircraft has been put into spins with yaw rates up to 60 deg./sec., equal to a complete turn every 6 sec. “That’s pretty good. But we paddled off the flight-test aid and it recovered instantly,” he says.

                    Pilots also tested the ability of the F-35 to recover from a deep-stall in which it was pushed beyond the maximum AoA command limit by activating a manual pitch limiter (MPL) override similar to the alpha limiter in the F-16. “It’s not something an operational pilot would do, but the angle of attack went back and, with the center of gravity way back aft, it would not pitch over, but it would pitch up. So it got stuck at 60 or 70 deg. alpha, and it was as happy as could be. There was no pitching moment to worry about, and as soon as I let go of the MPL, it would come out,” Nelson says.

                    Following consistent recoveries, the test team opted to remove the spin chute for the rest of the test program. “The airplane, with no spin chute, had demonstrated the ability to recover from the worst-case departure, so we felt very confident, and that has been proven over months of high alpha testing,” says Nelson. “It also satisfied those at the Joint Program Office who said spin chute on the back is not production-representative and produces aerodynamic qualities that are not right.” Although there are additional test points ahead where the spin chute is scheduled to be reattached for departure resistance with various weapons loads, the test team is considering running through the points without it.

                    [ATTACH=CONFIG]39561[/ATTACH]
                    Following good recoveries from earlier high-alpha testing, F-35 evaluators are considering doing away with the spin chute for upcoming evaluations with asymmetric loads. The chute is pictured here during initial high angle-of-attack work. Credit: U.S. Air Force

                    With the full flight envelope now opened to an altitude of 50,000 ft., speeds of Mach 1.6/700 KCAS and loads of 9g, test pilots also say improvements to the flight control system have rendered the transonic roll-off (TRO) issue tactically irrelevant. Highlighted as a “program concern” in the Defense Department’s Director of Operational Test and Evaluation (DOT&E) 2014 report, initial flight tests showed that all three F-35 variants experienced some form of wing drop in high-speed turns associated with asymmetrical movements of shock waves. However, TRO “has evolved into a non-factor,” says Nelson, who likens the effect to a momentary “tug” on one shoulder harness. “You have to pull high-g to even find it.” The roll-off phenomena exhibits itself as “less than 10 deg./sec. for a fraction of a second. We have been looking for a task it affects and we can’t find one.”
                    Attached Files
                    Last edited by citanon; 04 Apr 15,, 02:37.

                    Comment


                    • I remember a while back we discussed concepts for future air combat and I posited that future manned aircraft would act as shepherd for networked UCAVs that did the sensing, and shooting. Looks like DARPA is actually trying out variations on this idea:



                      The crucial issue driving these designs is the need for human intervention to provide shoot/no shoot decisions and tactical plans in real time. Future UCAVs may be able to execute increasingly complicated automated tasks, but they will not match human intelligence on complex tasks like tactical planning and decision making. On the other hand, in a future combat environment where an advanced adversary is engaging in advanced EW, cyber warfare and targeting all nodes of friendly communication networks, it may be very difficult to ensure reliable real time, high bandwidth communications with UCAVs engaged in combat.

                      Thus, you need to put the human controller in a combat aircraft within line of sight of the UCAVs where they can use low probability of intercept and jamming resistant narrow beam communications to send massive amounts of data gathered by their sensors for evaluation and processing by the human operator and the more powerful computers aboard his plane.

                      DARPA seems to be taking this concept to the max by conveying the UCAVs to the engagement area using large cargo aircraft, thus minimizing size, weight, and endurance requirements, and the "smarts" each expendable UAV needs, and thereby its cost. A very nice concept, and I think we'll see more of this in the future.

                      We may also see a comeback for two seater aircraft and the WSO.
                      Last edited by citanon; 07 Apr 15,, 01:00.

                      Comment


                      • In concept, this is not very different from the EC-121/E-3 and F-4/F-15 relationship for the past 50 years.

                        Comment


                        • Originally posted by citanon View Post
                          That's interesting, I didn't know that. Apparently the recent ADVENT program demonstration was very successful though. They had a running engine working within predictions on the ground.
                          I know the F-120 was tested on the YF-22 PAV-1, and it was reliable, but I guess the technology hadn't matured enough to justify the added risk of such an advanced engine. Also, the variable-cycle capability of the engine apparently added an additional layer of complexity to the engine and the flight software, which would've complicated the development process of the F-22.

                          The good news is the engine was further developed (just like the F-119) as an alternative powerplant for the F-35, although the Air Force ended up not funding the project, and GE has since discontinued development of the engine (although I'm sure many of it's advanced features ended up in the ADVENT engine).

                          Here's a good article on the ADVENT engine, which acknowledges it's heredity from the F-120, the main difference being the use of advanced materials in the ADVENT engine, such as ceramic matrix composites:

                          The Superjet: Building the Ultimate Flying Machine - GE Reports
                          "There is never enough time to do or say all the things that we would wish. The thing is to try to do as much as you can in the time that you have. Remember Scrooge, time is short, and suddenly, you're not there any more." -Ghost of Christmas Present, Scrooge

                          Comment


                          • Pratt & Whitney Developing Future Upgrade Options For F135 Engine | InsideDefense.com

                            F135 engine manufacturer Pratt & Whitney is working to leverage technologies developed through separate Air Force and Navy programs to reduce fuel burn and increase the performance of the Joint Strike Fighter engine, and could begin to transition those capabilities into block upgrades as soon as 2018. In separate interviews conducted during an April 2 media day, Pratt's President of Military Engines Bennett Croswell and Director of Advanced Programs and Technology Jimmy Kenyon told Inside the Air Force the company could begin incorporating block enhancements to F135 production engines as soon as 2020. The F-35 does not currently have a requirement for increased fuel burn or thrust, and the joint program office has not initiated a follow-on development program with Pratt. However, the company is involved in several other advanced engine development programs through the Air Force and the Navy that could have implications for the future performance upgrades. The first, the Navy Fuel Burn program, was initiated in 2012, and according to Kenyon the company is on contract through the Navy's requirements organization -- the Office of the Chief of Naval Operations -- through 2016 to develop enhancements to the F135 to improve fuel burn by about 5 to 7 percent. The goal is that any changes would introduce minimal disruption to the program, particularly as the JPO and Pratt prepare to ramp up engine production over the next few years. "Our Navy sponsor has taken a pretty strong stance on trying to make sure that it's retrofittable, it's common to all the variants, it's something you could actually go out there and reasonably, affordably effect," Kenyon said. Pratt will conduct a rig test this year, and an engine test and technology demonstration next year. Kenyon noted that right now, the effort is not officially a part of the F135 program, but he and Croswell said the company is in discussion with the JPO about incorporating it into the program's block upgrade plan. "To get it into the F135, there needs to be a requirement for it," Kenyon said. "So we're working on the cost-effectiveness of it. What are the life-cycle cost savings from reducing your fuel burn? What is the mission-effectiveness that you might get from the additional range or endurance you get out of the fuel burn improvement? What else can you do with those technologies?" Croswell noted that the company is looking at improving the F135's thrust by up to 20 percent and its fuel burn by up to 15 percent through this Navy program and through two other Air Force technology development efforts: Advanced Engine Technology Development and Advanced Engine Transition Program. The service requested $246 million for the two programs in its fiscal year 2016 budget request. Since 2011 Pratt has been involved with AETD, a program managed by the Air Force Research Laboratory that is aimed at maturing adaptive engine technologies to develop a more fuel-efficient future jet engine. Through AETD, Pratt and General Electric have conducted a number of technology demonstrations and are gearing up for a design review in late April. "One of the goals of AETD is to develop an engine design, notionally a production engine or an engine that looks like a product that could eventually come out and then do a full design review on that engine and understand what the engine would look like, what the engine capabilities are, how mature the technology in the engine is and what are the risks associated with continuing the development beyond that," Kenyon said. He continued: "We're really going through a pretty rigorous design review so that you understand very deeply what's in that engine. And that's a design review that we hold with the customer so that the customer can gain a lot of confidence in our design and in the viability of that design moving forward." After the design review, there are some additional smaller demonstrations as well as two major demonstrations next year, Kenyon said. The work Pratt and GE have performed on AETD will carry forward into AETP, which is a technology transition effort meant to move AETD technologies forward into a program of record for a next-generation jet engine. The service has said it will likely issue contracts to Pratt and GE as they are the only two companies that have moved through the entire AETP program. Kenyon said the service has indicated that the companies' AETD design will be the design that carries forward into AETP. Although the engines aren't being designed toward a particular, known platform, both companies have designed their engine to fit into an F-35, though the program is not intended as an F135 follow-on or alternative engine development effort. Kenyon said that when AETD began, conversations about next-generation needs and technologies were relatively immature. As those conversations have evolved over the last year or two, the service has started to talk about making sure these engine technologies are adaptable to a variety of applications. "That discussion on making sure we're able to go to different applications has become, I think, more and more focused," he said. "It's become more and more prominent, and I think more and more a part of what they want to do." In terms of considering the implications of these Air Force and Navy technology programs for future F135 block upgrades, Croswell said that Pratt is simply trying to provide the JPO with options to save on sustainment and maintenance costs while also improving the engine's performance over time. "What we're trying to do is provide options," he said. "Do they want more durability? Do they want better fuel burn? Do they want more thrust? We're going to put options on the table."
                            Sustainment Goals Along with looking at enhancements to improve the performance of the F135, Pratt has set goals for reducing sustainment costs by 30 percent by developing an enhanced engine program similar to what it established for the F100 engine, which powers the F-15 and F-16. The package, Croswell said, focuses on extending the life of the engine and performing enhanced repairs rather than installing new parts. The company is currently simulating the engine's lifetime performance by running it above its specified life in order to determine which parts may need design changes in order to last. "We'll just continue to run the engine and determine what parts don't have that life, and then we'll make design changes so that we bring the whole engine along to a higher life capability," Croswell said. The work that's happening now in the System Development Demonstration phase, which ends next year, will move into a Component Improvement Program, which will then shape the engine enhancement package, Croswell said, noting that the company is about five or six years away from knowing what that package will look like. -- Courtney Albon

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                            • I just came across this canadian tv show on the F 35. What do wabbits think of it?
                              I do understand that most of Mr Sprey's comments have been dismissed by you in earlier pages and threads, but the rest of it especially on the mind boggling expense was pretty bad.

                              Last edited by bolo121; 25 Jul 15,, 08:11.
                              For Gallifrey! For Victory! For the end of time itself!!

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                              • Engines are actually more complicated to design than the aircraft itself. ADVENT is pretty much amazing solution though.

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