GE XA100 and P&W XA101 AETP engines

GeorgeA

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GE and P&W are developing 45K-class three-stream AETP demonstrators for F-35 retrofit, PCA/F-X, and F/A-XX. Official designations are XA100 for GE and XA101 for Pratt. Note the introduction of a new designator, A, to go along with J for turbojet and F for turbofan.

http://aviationweek.com/aviation-week-space-technology/sixth-gen-xa100-and-xa101-fighter-engine-studies-ramp

Sixth-Gen XA100 And XA101 Fighter-Engine Studies Ramp Up
Guy Norris | Aviation Week & Space Technology

May 9, 2017
The age of the adaptive cycle engine as a new class of combat aircraft propulsive system in its own right is edging closer to reality with detailed design now underway of the first three-stream demonstration units under the U.S. Air Force’s Adaptive Engine Transition Program (AETP).
AETP will mature three-stream engine technology for the future U.S. Navy F/A-XX and the Air Force’s F-X sixth-generation fighters. Targeted initially at the 45,000-lb.-thrust class, the engine is also baselined to fit within the existing confines of the F-35A engine bay, making it a contender to replace the Joint Strike Fighter’s current Pratt & Whitney F135 from the mid-2020s onward......

To underline the importance of this step toward a new generation of engine technology, the Air Force has broken with tradition by designating the two AETP demonstrators as the XA100 and XA101. Instead of following on from the F for “fan” or “turbofan” series, which most recently saw the F135/136s developed for the F-35, the new naming convention of “A” for adaptability is a milestone on a par with the designation “J” for the turbojet series in the 1940s. The XA100 is being developed by GE, and the XA101 by Pratt.

The company[GE] is progressing through the final phases of the AETD program by conducting component evaluations and running or evaluating data from three rig tests of a compressor, core engine and adaptive fan module. The compressor test, which was run at Wright-Patterson AFB, Ohio, was completed in September. “We have completed the analysis, and the data is flowing into AETP,” says McCormick. Work on the fan rig is ongoing in the same compressor research facility at Wright-Patterson. “That’s nearly complete, and we expect to finish sometime [in May],” he adds.

The third, and final, large-scale rig test is the core engine, also expected to wrap up late in May or early in June. “It is a pretty challenging program because it is very complex. With an adaptive cycle engine with the three streams and heat exchangers, when you run the core you have to simulate the rest of the engine. It is actually more complicated to run than a full-up engine test because we must adapt the facility to simulate the inputs from the rest of the engine,” McCormick explains.

Although the overall pace of testing has been slower than hoped, McCormick says: “We are still making great progress and have over 30 hr. of tests on the core.”....

As part of earlier AETD tests, GE ran an F414 with flaps and seals made from an oxide/oxide ceramic CMC similar to parts now used in the production version of the Passport business jet engine. An F414 was also fitted with second-stage low-pressure turbine blades made from another form of CMC. PMCs, which are composed of short or continuous fibers bound in an organic polymer matrix, are also well-known in the industry, and air splitters made from the PMC-based PMR-15 are widely used in engines. “The difference is where we are applying them, and using them in more complex parts,” says McCormick.

Although GE declines to provide a comprehensive AETP schedule, it is believed the detailed design review is slated for late 2017, followed by release of drawings for building a full engine. “We are actually starting into the supply-chain process now of getting hardware defined, so there is definitely an engagement,” says McCormick. The company is expected to build three test engines starting in 2019, with ground runs due later that year and set to run through 2020. The first engine will test the basic mechanical design of the engine, the second will assess performance and operability, and the third will assess durability...

Pratt, which has so far described very little of its AETP plan, was expected to have begun running an adaptive three-stream fan with an F135 earlier this year under the final phase of AETD.

PHOTO: Festooned with test wiring, GE’s Advanced Engine Technology Development program core demonstrator is close to completing evaluation in the company’s A1 test cell. Credit: GE
 

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PCA with two 45k class engines, 90k total thrust, gives me the warm and fuzzies ;D
 
To quote from the article,

"There is still no decision as to where this suite of technology will go with respect to a platform. But it is designed to fit in the F-35, and we have integration work going on with Lockheed Martin. However, no solid decisions have yet been made on where this will go into the fleet, and we need to mature the technology to the point where that decision will be easier to make."

It's designed to fit into the space for an F135, but the timetable for maturing the technology is such that it won't be production ready until the mid-2020s, making it either a retrofit option, or better geared for 6th gen fighter applications.
 
The question is whether the intake requirements for the XA100/101 engines are so different from the F135 that retrofitting them will drive major structural, aero, and stealth changes. If the differences are, for example, close to what was needed to accommodate the F110 in aircraft originally designed for the F100, the retrofit is a more likely scenario.
 
bobbymike said:
PCA with two 45k class engines, 90k total thrust, gives me the warm and fuzzies ;D

A giant YF23 look alike pushed day 90k thrust.... Northrop .... please, for the love of all that's holy, make this happen!
 
George Allegrezza said:
The question is whether the intake requirements for the XA100/101 engines are so different from the F135 that retrofitting them will drive major structural, aero, and stealth changes. If the differences are, for example, close to what was needed to accommodate the F110 in aircraft originally designed for the F100, the retrofit is a more likely scenario.

IIRC, the AETP program was specified to fit in F135 space, no? Or has there been news about the intake requirements for AETP? Assuming B-21 is using dry version of F135 it would be a bummer if AETP is not a direct fit for the two latest airframes.

I'd imagine that PW is itching to integrate whatever they've learned into block upgrades of F135 production to get a jump on GE.
 
NeilChapman said:
IIRC, the AETP program was specified to fit in F135 space, no? Or has there been news about the intake requirements for AETP?

There's internal fit, and then all the details like CG, inlets, nozzles, fuel cooling circuits, and any impact on the OML. Plus, of course, the spawn of Satan that we know as software upgrades.

I'd imagine that PW is itching to integrate whatever they've learned into block upgrades of F135 production to get a jump on GE.

Certainly true for some major components. P&W has previously laid out F135 upgrades that will yield 5-8% better SFC, and perhaps some of the AETP-derived upgrades could add more to that, maybe as MLU-type retrofits to existing engines.
 
P&W plan to incorporate XA101 technology into growth versions of the F135:

Pratt Forges Ahead With F-35 Engine Upgrade Plans, Eyes Next Gen
Jun 5, 2017 Lara Seligman and Guy Norris | Aviation Week & Space Technology

Pratt & Whitney reached a new milestone in its road map for upgrading the F135 turbofan that powers the Joint Strike Fighter, and is looking to leverage that success to help secure the next generation of fighter propulsion.

The engine maker recently completed key tests of a proposed core upgrade package for the F135, confirming the potential for substantial fuel savings and higher thrust as soon as 2020. Crucially, the improved performance would come at a reasonable price to the U.S. government; the upgraded powerplant is “cost-neutral” from a procurement perspective, says Matthew Bromberg, president of Pratt & Whitney Military Engines.

But the F-35 is planned to fly far beyond 2020—until 2070, if recent Pentagon estimates prove correct. The fighter will need an engine that can keep pace with technological advancements for the next five decades. For now, as prime contractor on the F-35 powerplant, Pratt has a foothold in current and near-term U.S. fighter propulsion. But as threats and technologies evolve, that may change.

PATH AHEAD FOR F-35 ENGINE
Pratt and Whitney’s GO 1.0 upgrade promises 6-10% more thrust and 4-6% fuel-burn reduction

Upgrade package would be “cost neutral”

GO 2.0 would incorporate additional adaptive engine technology in development through AETD/AETP

Adaptive architecture seen as “umbrella” for future fighter propulsion

Both Pratt and General Electric are working under the U.S. Air Force-led Adaptive Engine Technology Demonstration (AETD), as well as the follow-on Adaptive Engine Transition Program (AETP), to test technology for a new generation of fighter engines. Under AETP, Pratt and GE are developing demonstrators—Pratt’s XA101 and GE’s competing XA100—to pave the way for an adaptive, 45,000-lb.-thrust-class combat powerplant, as well as the possible reengining of the JSF.

Hoping to stave off competition from GE and other engine makers, Pratt has framed its F135 upgrade effort as the first step in a long-term plan for fighter propulsion based on adaptive engine technology. That not only refers to the three-stream adaptive cycle that industry is developing, but also adaptive controls, an adaptive sustainment system and eventually perhaps an adaptive core that can handle unique operating pressure ratios, Bromberg says.

Pratt’s F135 modernization plan is envisioned as a seamless bridge to a next-generation fighter engine—the initial core upgrade package, or Growth Option (GO) 1.0, is just the first step.

“As each upgrade becomes available, we will look at taking the elements of that architecture suite and inserting that into the motors as available,” says Bromberg. “Adaptive architecture is the umbrella for the future of fighter engine propulsion, and Growth Option 1.0 will be the first incarnation of upgrading the JSF.”

GO 1.0 represents the first phase in a two-stage improvement road map scenario for the F-35 engine first unveiled in 2015 and promising 6-10% more thrust and a 4-6% fuel-burn reduction (AW&ST April 13-26, 2015, p. 26). It builds on a suite of core technologies evaluated since 2013 under the U.S. Navy-sponsored Fuel Burn Reduction (FBR) program. It also incorporates design improvements developed by Pratt under earlier technology programs including the Air Force-supported component and engine structural assessment research, known as Caesar, which focused on the F135’s predecessor, the F-22’s F119 engine.

Evaluation of the package, which is focused on the high-pressure compressor, turbine and combustor stages, was done using testbed engine FX701-01 at Test Site A3 at Pratt’s West Palm Beach, Florida, facility. Although not a program of record for the F-35, Pratt says risk-reduction work performed on the test rig has proved GO 1.0 can be executed as a low-cost means of improving the aircraft’s range and acceleration.

“We feel very confident that we could launch a program, complete the testing and EMD [engineering, manufacturing and design], and have a production change or retrofit available by 2020,” explains Bromberg. If given “the green light” to begin work on a formal improvement package this year, Bromberg says the development would align with the JSF’s planned Block 4.2 upgrade.

Pratt believes GO 1.0 is attractive to the F-35 community, primarily due to affordability. After the “relatively short” EMD program, the U.S. government would have to swap out the old engine for the new, upgraded system across the fleet, but that could be accomplished on an attrition basis during scheduled depot maintenance.

“We could cut it into production and we could cut it into depot retrofits . . . if you did it on an attrition basis when you are replacing hardware anyway, the cost of the hardware is roughly the same,” Bromberg points out. If the government decides to force a retrofit, it must pay for the core module, but that would be “the incremental cost.”

A key advantage of GO 1.0 is that it fits into the existing sustainment structure for the F-35, including the troubled Autonomic Logistics Information System (ALIS) that provides the maintenance backbone of the fleet. Lockheed Martin has encountered challenges integrating the Pratt engine into the latest ALIS iteration, 2.0.2, and just started delivering the new system to the fleet in April.

“It’s just a drop in part number change and suite of health management tools that will go right into ALIS, so [there are] no changes to ALIS” aside from updating part changes and the new health-monitoring algorithms, says Bromberg. “If you go to a new core it’s an entirely new engine. It requires an entirely new instance of ALIS or a complete upgrade.”

In addition, GO 1.0 is “variant common,” so it can be dropped into any of the three U.S. JSF variants or partner aircraft, Bromberg says.

The second phase of Pratt’s F135 road map, GO 2.0, would incorporate additional adaptive engine technology features in development through Air Force and Navy-supported initiatives, primarily including AETD and AETP. Both Pratt’s XA101 and GE’s XA100 are initially sized for potential application on the F-35.

GO 2.0, which also could include elements of the Navy’s variable cycle advanced technology program, would introduce more radical changes including adaptive features in the low-pressure compressor and turbine. Pratt has said the second upgrade phase has the potential to generate a thrust improvement of up to 15% and as much as a 20% reduction in fuel burn. It could be developed in the next “4-8 years” depending on the timing of the first upgrade and the continuing development of the AETP, Bromberg says.

Similarly Pratt also sees potential for elements of GO 1.0 to pave the way for elements of XA101.

“The primary purpose of the FBR is to test the core, the geometry and the coatings. We feel good about it and it reduces the risk of Growth Option 1.0. But definitely some of the technologies in that core are directly applicable in terms of growth materials and aerodynamic geometry, and that will go into XA101,” Bromberg explains.

Meanwhile, Pratt has started tests of a three-stream fan mounted on an F135 under AETD and is poised to begin evaluation of an all-new core to prove the technology at the heart of its future adaptive engine. The core run is “in front of us, and is further risk reduction for the XA101 program,” says Bromberg. The three-stream fan test engine also is configured with a specially modified augmenter and exhaust system to handle the adaptive-cycle flow demands.

At its core, Pratt’s overall strategy is to provide options for whatever path the Air Force chooses.

“We have this umbrella strategy of adaptive architecture and we will start proving out the technologies one by one,” Bromberg says. “We are trying to provide options to spiral them in at relatively low-risk, low-cost programs.”

PHOTO:pratt & Whitney is proposing an initial upgrade package for the F-35 engine that promises fuel reductions of up to 6% and as much as 10% higher thrust as soon as 2020. Evaluation of the package, which is focused on the high-pressure compressor, turbine and combustor stages, has been undertaken using testbed engine FX701-01 at Test Site A3 at Pratt’s West Palm Beach, Florida, facility. Credit: Pratt & Whitney
 

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AETP may be splitting into two programs: F135 replacement and classified 6th-gen development.

https://www.flightglobal.com/news/articles/usaf-starts-work-on-defining-adaptive-engine-for-fut-450053/
 
George Allegrezza said:
AETP may be splitting into two programs: F135 replacement and classified 6th-gen development.

https://www.flightglobal.com/news/articles/usaf-starts-work-on-defining-adaptive-engine-for-fut-450053/

That seems like it could be a good sign. Perhaps PCA planning is far enough along that a divergence of the technology has been required.
 
https://www.nextbigfuture.com/2018/09/drones-hypersonic-weapons-lasers-and-engines-for-next-generation.html?utm_source=dlvr.it&utm_medium=facebook

The sixth generation fighters and upgrades to older fighters over the next 10-20 years will involve better engines for more range and speed, hypersonic weapons, combat lasers, unmanned flight and drones.

Hypersonic missiles (mach 5 or faster) are already being introduced by Russia and China. The US is developing combat laser pods which will be added to fighter jets. Unmanned flight is being used for various planes. Large drones are being deployed to help with refueling existing military planes. Future large drones will fight alongside future fighter planes.

It will be another 10 years after that for hypersonic drones and hypersonic planes that will define the seventh generation of fighters.
 
I don't have the source, but there is a related news.

"Lawmakers push USAF for adaptive engine transition plan, propose $270M cut"

The Senate Appropriations Committee is proposing a $270 million cut to the Air Force's Adaptive Engine Transition Program and are calling on the service to deliver details on plans to transition the new engine technology into major programs like the F-35. The committee approved its version of fiscal year 2020 defense spending legislation this week. In a report accompanying the bill, lawmakers noted concern that no programs have formally mapped a plan to incorporate adaptive engine technology -- a major...
 

"...Senate appropriators have threatened to reduce the fiscal 2020 budget for the Adaptive Engine Transition Program (AETP) by nearly one-third. The $270 million cut would be “pretty devastating,” says David Tweedie, general manager of GE’s advanced combat engine program. The Air Force’s requested $878 million budget for AETP calls for running the ground-test rigs next year for the rival engine prototypes: GE’s XA100 and Pratt & Whitney’s XA101. ... "



"... The Air Force’s ability to respond in public to the Senate’s concerns are limited by the secrecy restriction on NGAD concepts, says Gen. David Goldfein, the Air Force chief of staff. But he suggests more testing for the adaptive engine is required beyond the ground-rig tests funded by the AETP program. ..."



"... GE’s Tweedie describes the XA100 as an easy reengine candidate for the F-35. “That is absolutely the most near-term opportunity to transition to a platform,” he says. “There’s a little bit of transition from a prototype to a true product.”

Pratt is developing the XA101 for the same purpose but offers a more pessimistic perspective on the possible complications arising from an F-35 reengining program.

Matthew Bromberg, president of Pratt & Whitney Military Engines, says the XA101 is only designed for insertion in the F-35A. It would take more airframe development work to adapt the engine for the carrier-based F-35C, and it is impossible to integrate with the rotating nozzle of the short-takeoff-and-vertical-landing F-35B, he says. These factors raise many questions. ... "
 
How about reveal plans to fit one on one of the F-35 test birds and conduct a flight test plan over the next 2-3 years? I mean, surely it cannot be as hard as producing a completely new fighter every five years...
 
No, engines are harder and take longer.

Exactly! Hence the sarcasm. Given the support these programs have had from Congress over the last few years it would be better for the AF to begin thinking of further testing and integration starting immediately after the FY20 activities concludes. A roadmap to flight test it over the FYDP should work with Congress and should get them the required funding.
 
It's also funny that PW brand the X101 as incompatible with the folding nozzle of the Bee. I don't see why a co-axial design would not be possible (2 stream at nozzle level) with what info we have so far.
It will be interesting to follow what's the position of GE on that.
 
Think the problem has to do more with how and where the pull off the air for the roll posts. How would you keep the streams separate at the rear nozzle as it articulates or would you need to?
 
Raytheon Technologies is working to take the heat off a new generation of fighters

The solutions the company is developing will have applications for a range of platforms, including the U.S. Air Force and U.S. Navy’s future fighter programs, the U.S. Army’s Future Vertical Lift program, battlefield air mobility, and the F-35 and F-22 modernization programs.

“We want to find the most efficient way to integrate between propulsion, electric power generation and thermal management,” said Bill Dolan, vice president of engineering and technology at Collins Aerospace’s Power & Controls unit. “Current systems cannot support the increased heat loads that future enhancements will require without detracting from desired aircraft performance, so we are actively exploring new architectures, new packaging and new methods of integration.”

“As we look to the future, power and thermal management system capacity will be a key enabler for next-generation fighter aircraft as well as for capability growth of existing aircraft,” said Dave Stagney, senior director for Pratt & Whitney’s GATORWORKS organization. “Pulling additional power from our engines under existing approaches has a significant negative impact on engine life and maintenance costs. Our integrated approach – leveraging advanced systems architectures but also state-of-the-art digital engine controls – not only results in lower fuel burn and lifecycle costs, but also less weight, better packaging and higher overall aircraft performance.”

 

Some figures mentioned here are interesting. For the F-35A, 30% increase in range and 18% reduction in acceleration time parameter. The modulation of the third stream will be interesting; will it be something that’s commanded by the pilot, or automatically incorporated in the engine control system?
 
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GE-sponsored story about the XA100, so obviously there’s an agenda here, but the benefits they are touting from the new architecture are quite substantial. Also, I find it interesting that GE continues to state that the XA100 is compatible with both the F-35A and F-35C. If this is the case and GE/LM didn’t make a massive oversight, then this can be quite a powerful argument for the XA100.

The nerd side of me hopes that an AETP engine will be adopted especially considering the projected service life of the aircraft, but realistically, to borrow a phrase from P&W’s Matthew Bromberg, the engine will have to “buy its way in” to the program.
 
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Also, I find it interesting that GE continues to state that the XA100 is compatible with both the F-35A and F-35C. If this is the case and GE/LM didn’t make a massive oversight, then this can be quite a powerful argument for the XA100.
That's not a real achievement as they're basically the same engine. Now if the GE engine were compatible with the F-35B that would be something.
 
Both the adaptive engines are designed for similar requirements so both should fit the F-35C. That said, it has been revealed that to do so, the tailhook needs to be moved. That wouldn't be different from one engine to the other. They are both virtually designed around the same specs.

Congress's insistence on a completely new competitively acquired new engine will offer a fairly significant capability but at a cost that will likely severely limit what other enhancements are funded particularly in a future block 5. We are basically back to square one in terms of depot capacity, investments and sustainment and if we go forward with two engines (keep the F-135 on the B and C) then that means doubling these investments.
 

December 15, 2021

EVENDALE, Ohio – GE has concluded phase 1 testing on its second XA100 adaptive cycle engine as part of the U.S. Air Force’s Adaptive Engine Transition Program (AETP). Phase 1 testing took place at GE’s Evendale, Ohio, altitude test facility and enabled GE to continue gathering high-quality performance data validating the engine’s transformational propulsion capability. Phase 2 tests will begin at the U.S. Air Force’s advanced testing facilities at Arnold Engineering Development Complex (AEDC) in the first quarter of 2022.

“Phase 1 testing allowed us to further characterize the operation of the engine and puts us in a great position to begin Phase 2 testing at AEDC,” said David Tweedie, GE Edison Works’ general manager for Advanced Combat Engines. “We continue to burn down risk with full-scale engine testing, which is why the XA100 is the lowest risk, most capable, and fastest approach to keep the F-35 a preeminent fighter platform for the long term.”

GE’s XA100 became the world’s first ever flight-weight, three-stream adaptive cycle engine in December 2020 before initiating tests on its second engine in August 2021. GE’s engine is uniquely designed to fit both the F-35A and F-35C without any structural modifications to either airframe, enabling better aircraft range, acceleration, and cooling power to accommodate next-generation mission systems.
 

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