Lets suppose the F-35 gets all the upgrades!

* It gets a new engine from the Adaptive Engine Tranistion Program.
* It gets Block 4 software, and then a bug-free very good Block 5.
* The radar gets updated to whatever is best 10 years from now.
* New missiles are developed. all sized to fit in the F-35 weapons bay.
* It gets a large spare parts inventory, and a system that can do engine overhauls in a timely manner.

If Congress invests like this, how much better can the F-35 be?
Would such an fighter be competative against whatever China will have in 10 years?

Is there any reason to think it wouldn't be?

My opinion is that the F-35 will only get upgrades that reduce cost.

The USAF will soon have the 6th generation fighter to offer high performance. The F-35 will move down the ranks to become the medium capability fighter. The F-35 is needed to make up the numbers so operating and purchase costs will be the priority. If the F-35 gets newer tech and the costs go up then it opens the door for Boeing with a fighter version of the T-7 to do homeland defense and ANG work.

In terms of export customers, if they stop fitting newer technology then the current technology in the F-35 will no longer be that sensitive in 10 years time. It will be able to expand its export potential to riskier customers. All current F-16, F-15, Eurofighter, Typhoon and Gripen customers should be able to operate the F-35 in 2040. We will no doubt see second hand F-35 offered to smaller nations just like the F-16.

The US Navy I doubt will want the adaptive engine either. Firstly it won't fit the F-35B and the US Navy with their Super Hornets went with the Enhanced Durability Engine offered by GE instead of increased thrust. The US Navy needs long range strike power and combined with the MQ-25 it gets that with the F-35C. They will probably also have loyal wingman drones paired up with the F-35C.

RJMAZ wrote:

My opinion is that the F-35 will only get upgrades that reduce cost.

The USAF will soon have the 6th generation fighter to offer high performance. The F-35 will move down the ranks to become the medium capability fighter. The F-35 is needed to make up the numbers so operating and purchase costs will be the priority. If the F-35 gets newer tech and the costs go up then it opens the door for Boeing with a fighter version of the T-7 to do homeland defense and ANG work.

In terms of export customers, if they stop fitting newer technology then the current technology in the F-35 will no longer be that sensitive in 10 years time. It will be able to expand its export potential to riskier customers. All current F-16, F-15, Eurofighter, Typhoon and Gripen customers should be able to operate the F-35 in 2040. We will no doubt see second hand F-35 offered to smaller nations just like the F-16.

The US Navy I doubt will want the adaptive engine either. Firstly it won't fit the F-35B and the US Navy with their Super Hornets went with the Enhanced Durability Engine offered by GE instead of increased thrust. The US Navy needs long range strike power and combined with the MQ-25 it gets that with the F-35C. They will probably also have loyal wingman drones paired up with the F-35C.

Are there upgrades whos primary purpose is to reduce cost? I’m not aware of any relatively modern at the time fighters that were upgraded for that purpose.

Avatar2go wrote:

Is there any reason to think it wouldn't be?

No one knows what China will have in 10 years. But when my guess some brand new fighter is in the works.

kitplane01 wrote:

Are there upgrades whos primary purpose is to reduce cost? I’m not aware of any relatively modern at the time fighters that were upgraded for that purpose.

The obvious upgrade is to the structural strength of the aircraft. The F-16 and F-15's produced today can fly for thousands of hours longer than the original models. This dramatically reduces the lifecycle cost.

The service life of an aircraft plays a big part in determining how many aircraft should be initially purchased. It is not always about a fixed number of frames but how many frames are needed to last say 30 years. The resale value on the second hand market will also be significantly improved.

Parts that are wearing out prematurely can also have upgraded parts developed. This is very common for most fighter aircraft.

Another upgrade is engine durability. I could list dozens of fighters that have received an improved engine that gave significant maintenance cost reductions. Thrust improvements in many cases were negligible.

Computer systems have also been swapped out for newer units which are nearly always cheaper. The F-35 has already had its computer systems upgraded from what was flown in the aircraft 10 years ago. These computers were fitted for cost saving not for greater processing power. A $500 computer today roughly has similar performance of a $50,000 computer from 10 years ago. So I expect newer and significantly cheaper computer systems to be fitted.

Stealth coatings have also been developed that are cheaper and have lower maintenance. This is entirely driven by cost not performance.

kitplane01 wrote:

Avatar2go wrote:

Is there any reason to think it wouldn't be?

No one knows what China will have in 10 years. But when my guess some brand new fighter is in the works.

True, but historically China has copied existing designs, and the copies have not had the same capabilities as the originals. When 6th gen fighters appear, no doubt they will copy those too. That doesn't mean the F-35 will not remain a potent adversary.

Even the F-15 and F-16 are still quite formidable aircraft, it's just that they are highly visible to modern radars, at a distance that puts them in missile range before their own weapons are within range. The F-35 won't have that same issue. It may become less stealthy over time, but it will still have good survivability.

The Chinese have an advantage in that they can crank out assets in greater numbers, if they choose. Quantity has it's own quality. But I don't think it's likely they will emerge with a new technology that the West doesn't have, or can't answer. Or that will greatly diminish the effectiveness of the F-35.

kitplane01 wrote:

Are there upgrades whos primary purpose is to reduce cost? I’m not aware of any relatively modern at the time fighters that were upgraded for that purpose.

A perfect example is the F-16 block 60 and F-16 block 70. They downgraded the radar in the block 70 because it was significantly cheaper. Both radars are from the same manufacturer too.

The APG-80 that is fitted to the UAE Block 60 F-16's was state of the art at the time. The APG-83 is used in the block 70 and it has a smaller radar diameter with much cheaper off the shelf components with a lower detection range.

This cheaper APG-83 radar allows the block 70 to hit a lower price point so Bahrain, Slovakia and Taiwan are purchasing brand new aircraft.



The APG-83 is so small that it can also be offered on the F/A-50.

It is highly like there will be never and cheaper AESA TR modules in 10 years time. The F-35 will probably get a radar that is a fraction of the cost of the current radar. Cost would be the primary concern.

That's not the full story on the F-16 radar, though. The APG-80 was an export model on the Block 60 for the UAE. It could not be backfitted to earlier US blocks because of the lack of cooling capacity on those aircraft. Export Block 60 had enhanced cooling to support APG-80.

It was supportable on the Block 70 as well, but the USAF decided on the APG-83, which has both less cooling requirements and variable power modes. This allows it to be backfitted to Block 20 and above, while having almost the same performance in the Block 70 as the APG-80.

Most importantly, the APG-83 is a huge capability increase for all the F-16 aircraft that will receive it. That was the motivation for the upgrade. The cost is lower because costs routinely decline for electronics over time, but it was not done for that reason, it was done for the performance enhancement.

Avatar2go wrote:

That's not the full story on the F-16 radar, though. The APG-80 was an export model on the Block 60 for the UAE. It could not be backfitted to earlier US blocks because of the lack of cooling capacity on those aircraft. Export Block 60 had enhanced cooling to support APG-80.

We aren't talking about back fitting. The F-16V block 70 aircraft for Bahrain, Slovakia and Taiwan are new builds. So they could easily have the same cooling as the block 60 UAE jets and fit the bigger APG-80 radar.

They do not want the APG-80 due to the huge cost. This is the perfect example where brand new aircraft are getting a smaller and inferior radar because of reduced cost. I agree that the APG-83 is still better than a 40 year old radar but that was not the question.

The question was "Are there upgrades whos primary purpose is to reduce cost?"

The APG-83 is 100% about reducing cost and making block 70 aircraft cheaper than block 60.

Also the APG-63(V)4 on newer Eagles got the back end processor from the Super Hornet to save money. It still has the same transmitter as the V3 radar.

I believe I said that. Also that the performance of the APG -83 is similar to the APG-80 on the Block 70 because of the availability of cooling and power. That is the limitation, not the radar itself.

RJMAZ wrote:

This is the perfect example where brand new aircraft are getting a smaller and inferior radar because of reduced cost.

But is the APG-83 really inferior?
Might it have a superior receiver, better signal processing abilities and /or better ECCM capabilities?
Transmit power isn't everything.

Avatar2go wrote:

That's not the full story on the F-16 radar, though. The APG-80 was an export model on the Block 60 for the UAE. It could not be backfitted to earlier US blocks because of the lack of cooling capacity on those aircraft. Export Block 60 had enhanced cooling to support APG-80.

It was supportable on the Block 70 as well, but the USAF decided on the APG-83, which has both less cooling requirements and variable power modes. This allows it to be backfitted to Block 20 and above, while having almost the same performance in the Block 70 as the APG-80.

Most importantly, the APG-83 is a huge capability increase for all the F-16 aircraft that will receive it. That was the motivation for the upgrade. The cost is lower because costs routinely decline for electronics over time, but it was not done for that reason, it was done for the performance enhancement.

Correct, and this is the reason why UAE F-16's have the most powerful variant of the F-110 engine; they need the extra engine power for the additional cooling and power requirements for the radar and all of the additional systems added to the jet requires.

To fit the AN/APG-80 to an older F-16 version, it would require significant modifications to the aircraft's electrical and cooling systems, plus an upgraded engine in order to effectively power and cool the radar. AN/APG-83 does not require such modifications to the aircraft.

ThePointblank wrote:

To fit the AN/APG-80 to an older F-16 version, it would require significant modifications

Again we aren't talking about back fitting. That is irrelevant to the discussion.

Brand new block 60 F-16's were coming off the production line with the more powerful APG-80 radar with all of the required modifications built into the design. The new build block 70 received a less powerful radar when the production line was already producing new F-16's with the required cooling systems for the more powerful APG-80 radar.

It would have been easier for Lockheed to just continue to offer and produce block 60 F-16's for new builds with the APG-80 as the production line is already set up. The cheaper APG-83 could then have been kept for back fitting to older F-16's only. But Lockheed decided it would be much better to fit a much cheaper radar to new build aircraft as well to allow the F-16 to be more competitive.

Avatar2go wrote:

kitplane01 wrote:

Avatar2go wrote:

Is there any reason to think it wouldn't be?

No one knows what China will have in 10 years. But when my guess some brand new fighter is in the works.

True, but historically China has copied existing designs, and the copies have not had the same capabilities as the originals. When 6th gen fighters appear, no doubt they will copy those too. That doesn't mean the F-35 will not remain a potent adversary.

No one thinks the J-10 or the J-20 are a copy of anything ... and most people believe both are potent fighters. What you wrote was more true in the past than now.

Avatar2go wrote:

Even the F-15 and F-16 are still quite formidable aircraft, it's just that they are highly visible to modern radars, at a distance that puts them in missile range before their own weapons are within range. The F-35 won't have that same issue. It may become less stealthy over time, but it will still have good survivability.

What you wrote about the F-15/F-16 is kind of like "they are good except they're gonna get shot down".

What does "less stealthy but good surviviability" even mean? It sure doesn't mean "successfully runs from missiles" or "can take a missile hit and keep flying".

RJMAZ wrote:

ThePointblank wrote:

To fit the AN/APG-80 to an older F-16 version, it would require significant modifications

Again we aren't talking about back fitting. That is irrelevant to the discussion.

Brand new block 60 F-16's were coming off the production line with the more powerful APG-80 radar with all of the required modifications built into the design. The new build block 70 received a less powerful radar when the production line was already producing new F-16's with the required cooling systems for the more powerful APG-80 radar.

It would have been easier for Lockheed to just continue to offer and produce block 60 F-16's for new builds with the APG-80 as the production line is already set up. The cheaper APG-83 could then have been kept for back fitting to older F-16's only. But Lockheed decided it would be much better to fit a much cheaper radar to new build aircraft as well to allow the F-16 to be more competitive.

The Block 60 was a limited production run before production resumed of the regular Block 50/52+, and adjusting for inflation, costs as much as a F-35 does right now.

If you cannot afford a F-35 but still want a modern fighter jet, the F-16 Block 60 would not be the way to go. The fact that there has been only one customer of this version of the F-16 says what the market is saying; they want a cheaper F-16 variant, and they want the ability to upgrade their existing aircraft to the same standard easily.

kitplane01 wrote:

What you wrote about the F-15/F-16 is kind of like "they are good except they're gonna get shot down".

What does "less stealthy but good surviviability" even mean? It sure doesn't mean "successfully runs from missiles" or "can take a missile hit and keep flying".

Low observability messes with the entire kill chain.

In order to successfully kill a target, you must:
- Identify a target;
- Fix the target's location;
- Track the target's movements;
- Target the target with a weapon;
- Engage the target with a weapon, and;
- Assess the results of the attack to see if any follow up is required

This is known by the acronym F2T2EA. You break or interfere with any of the above, you stop the opponent from making a kill. Low observability messes with all aspects of the kill chain, by significantly reducing the chances of success for all aspects of the kill chain.
- If you can't identify a target, you can't engage the target;
- If you can't figure out a target's location, you are just shooting blindly;
- If you can't track the target's movements, you are just shooting blindly at where the target was;
- If you can't aim a weapon at the target, you can't shoot;
- If you don't know the results of your engagement, you don't know if you killed the target

kitplane01 wrote:

What does "less stealthy but good surviviability" even mean? It sure doesn't mean "successfully runs from missiles" or "can take a missile hit and keep flying".

LO isn't an on/off thing. It primarily reduces the range at which an opponent can recognize and engage you. Flying directly over a SAM site should still be avoided but you can maybe come safely within 10 or 20 miles of a radar. If that range is increased to 30 or 40 miles with future radars, you still keep a lot more operational freedom compared to traditional aircraft.

Stealth can also help avoid missiles if you manage to break the tracking radar's lock after launch. Sure, most modern missiles feature an active homing system but that usually has a lot less range than the ground-based radar.

ThePointblank wrote:

The Block 60 was a limited production run before production resumed of the regular Block 50/52+, and adjusting for inflation, costs as much as a F-35 does right now.

If you cannot afford a F-35 but still want a modern fighter jet, the F-16 Block 60 would not be the way to go. The fact that there has been only one customer of this version of the F-16 says what the market is saying; they want a cheaper F-16 variant, and they want the ability to upgrade their existing aircraft to the same standard easily.

Yes that agrees with what I've been saying all along. We should go back to the original question.

kitplane01 wrote:

Are there upgrades whos primary purpose is to reduce cost? I’m not aware of any relatively modern at the time fighters that were upgraded for that purpose.

The F-16 block 70 is an upgrade where the primary purpose was to reduce cost. As the market was saying they wanted a cheaper F-16 variant compared to the block 60.

The market will want a cheaper variant of the F-35 in 20 years time for the low end market. That is why in my first post I said that the F-35 will not get significant capability improvements. The only goal moving forward will be to reduce cost. If the significantly cheaper parts give a tiny capability improvement that will simply be a convenient side effect.

kitplane01 wrote:

No one thinks the J-10 or the J-20 are a copy of anything ... and most people believe both are potent fighters. What you wrote was more true in the past than now

The J-10 is a rough copy of the Saab Viggen. The J-20 is more original but copies many elements of the F-22, adapting them to the J-10 canard design.

What you wrote about the F-15/F-16 is kind of like "they are good except they're gonna get shot down".

USAF doctrine would employ 5th gen fighters to address adversary air superiority & defense assets. After which the 4th gen fighters can operate effectively, even against air-to-air threats.

What does "less stealthy but good surviviability" even mean? It sure doesn't mean "successfully runs from missiles" or "can take a missile hit and keep flying".

It means that the stealth of any aircraft is degraded over time, by changes in adversary capabilities and tactics. The F-117 was extremely difficult to detect when introduced, and thus had no defensive capabilities, but that changed with time.

Aircraft like the F-22 and F-35 will also be degraded over time, but they compensate with other abilities and tactics. They aren't one-trick ponies, they will still be formidable opponents.

While there are competing upgraded engine projects for the F-35, I still see the only real answer as being an upgraded F-135 that has enhanced durability, a modest SFC reduction of, at best, 10%, and perhaps a very slight thrust bump. Going with any other engine that's even being considered excludes the -B due to the lift fan. Excluding the -B and ruining the core commonality significantly hampers the running costs of the program which is already slated to be astronomical as is. The only possible situation where I see the -A having a different engine from the -B and -C (as the Navy won't want to have two separate engine pools) is if the -A somehow gains the ability to use the same engine as another large program, such as a 6th Gen fighter platform, or, maybe the B-21 is using an improved F-135 variant that it can share without forcing other F-35s onto the same platform.

Avatar2go wrote:

The J-10 is a rough copy of the Saab Viggen. The J-20 is more original but copies many elements of the F-22, adapting them to the J-10 canard design.

In what way is the J-10 a copy of the Viggen. They look nothing alike.

Nor does it look like the Gripen, for that matter, except for having a deltawing and canards. And that’s a quite common layout anyway.

petertenthije wrote:

Avatar2go wrote:

The J-10 is a rough copy of the Saab Viggen. The J-20 is more original but copies many elements of the F-22, adapting them to the J-10 canard design.

In what way is the J-10 a copy of the Viggen. They look nothing alike.

Nor does it look like the Gripen, for that matter, except for having a deltawing and canards. And that’s a quite common layout anyway.

Have to disagree. The J-10 development began right after the Viggen became established as a high performance fighter, that pioneered the canard-delta design. It also contains elements of the IAI Lavi, which was another derivative of the Viggen design. There are reports that the Chinese privately acknowledged the Lavi influence to the Israelis.

That's not to say it's a direct knockoff. The Chinese borrow ideas and concepts and apply them. Often the details are obtained through espionage.

The point of my post was that the Chinese are avoiding the huge R&D costs incurred by the West, by copying many of their ideas. But that doesn't put them in a leadership or innovative position.

Find the differences!

Yes, because the design concepts and IP are defined by appearance, right? Not by the borrowed material or the systems underneath the skin. In fact you can borrow any design, but as long as you don't make them look the same, you're good to go. Just ask any patent attorney.

LightningZ71 wrote:

While there are competing upgraded engine projects for the F-35, I still see the only real answer as being an upgraded F-135 that has enhanced durability, a modest SFC reduction of, at best, 10%, and perhaps a very slight thrust bump. Going with any other engine that's even being considered excludes the -B due to the lift fan. Excluding the -B and ruining the core commonality significantly hampers the running costs of the program which is already slated to be astronomical as is. The only possible situation where I see the -A having a different engine from the -B and -C (as the Navy won't want to have two separate engine pools) is if the -A somehow gains the ability to use the same engine as another large program, such as a 6th Gen fighter platform, or, maybe the B-21 is using an improved F-135 variant that it can share without forcing other F-35s onto the same platform.

The USAF has been working on new adaptive engines through its industrial partners in GE and PW; both GE and PW have based their adaptive engines off their F-35 engines (F136 and F135). One of the early end goals was for the engine to be a drop in replacement for the F135 and F136 for the F-35.

Such an engine would have a significant performance boost, along with decreased fuel consumption and thermal signature, and the USAF is contemplating the technology right now.

ThePointblank wrote:

LightningZ71 wrote:

While there are competing upgraded engine projects for the F-35, I still see the only real answer as being an upgraded F-135 that has enhanced durability, a modest SFC reduction of, at best, 10%, and perhaps a very slight thrust bump. Going with any other engine that's even being considered excludes the -B due to the lift fan. Excluding the -B and ruining the core commonality significantly hampers the running costs of the program which is already slated to be astronomical as is. The only possible situation where I see the -A having a different engine from the -B and -C (as the Navy won't want to have two separate engine pools) is if the -A somehow gains the ability to use the same engine as another large program, such as a 6th Gen fighter platform, or, maybe the B-21 is using an improved F-135 variant that it can share without forcing other F-35s onto the same platform.

The USAF has been working on new adaptive engines through its industrial partners in GE and PW; both GE and PW have based their adaptive engines off their F-35 engines (F136 and F135). One of the early end goals was for the engine to be a drop in replacement for the F135 and F136 for the F-35.

Such an engine would have a significant performance boost, along with decreased fuel consumption and thermal signature, and the USAF is contemplating the technology right now.

The GE version of AETP will fit the F-35A. They're saying with further development it should fit the F-35C as well. But would require substantial work to fit the F-35B, so not clear right now if that is possible.

The PW version of AETP will not fit any of the F-35 models, so they are pushing their enhanced F-135 instead. It fits all the models and has around 5% to 15% improvement in range & thrust, as opposed to 20% to 30% for the AETP engine.

The AETP engine will also cost significantly more than the enhanced engine, and will have a separate parts inventory and supply chain.

The DoD will likely not want to support two engines, since they declined the F-136. There is also the issue of buy-in from F-35 program partners around the world. So it's a complicated decision with many factors to evaluate.

If the AETP is not selected for a major program like the F-35 or B-21, it might be skipped for the upcoming Next Generation Engine Program (NGEP), which is now being considered for NGAD. That has raised concerns about maintaining the engine technology lead in the US, although NGEP may end up being an extension of AETP.

Avatar2go wrote:

ThePointblank wrote:

LightningZ71 wrote:

While there are competing upgraded engine projects for the F-35, I still see the only real answer as being an upgraded F-135 that has enhanced durability, a modest SFC reduction of, at best, 10%, and perhaps a very slight thrust bump. Going with any other engine that's even being considered excludes the -B due to the lift fan. Excluding the -B and ruining the core commonality significantly hampers the running costs of the program which is already slated to be astronomical as is. The only possible situation where I see the -A having a different engine from the -B and -C (as the Navy won't want to have two separate engine pools) is if the -A somehow gains the ability to use the same engine as another large program, such as a 6th Gen fighter platform, or, maybe the B-21 is using an improved F-135 variant that it can share without forcing other F-35s onto the same platform.

The USAF has been working on new adaptive engines through its industrial partners in GE and PW; both GE and PW have based their adaptive engines off their F-35 engines (F136 and F135). One of the early end goals was for the engine to be a drop in replacement for the F135 and F136 for the F-35.

Such an engine would have a significant performance boost, along with decreased fuel consumption and thermal signature, and the USAF is contemplating the technology right now.

The GE version of AETP will fit the F-35A. They're saying with further development it should fit the F-35C as well. But would require substantial work to fit the F-35B, so not clear right now if that is possible.

The PW version of AETP will not fit any of the F-35 models, so they are pushing their enhanced F-135 instead. It fits all the models and has around 5% to 15% improvement in range & thrust, as opposed to 20% to 30% for the AETP engine.

The AETP engine will also cost significantly more than the enhanced engine, and will have a separate parts inventory and supply chain.

The DoD will likely not want to support two engines, since they declined the F-136. There is also the issue of buy-in from F-35 program partners around the world. So it's a complicated decision with many factors to evaluate.

If the AETP is not selected for a major program like the F-35 or B-21, it might be skipped for the upcoming Next Generation Engine Program (NGEP), which is now being considered for NGAD. That has raised concerns about maintaining the engine technology lead in the US, although NGEP may end up being an extension of AETP.

The way I'm reading PW's statements is that they are more concerned about killing the golden goose they got with having exclusivity on the F-35 program, rather than any issue with their engine not fitting.

It also appears that PW is behind GE in terms of where they are in the development of their engine as well. Hence I suspect is the real reason why PW is so bullish on adaptive engines; they are behind, and in a competition, GE would likely be the winner of said competition, shutting them out of future F-35 sales and support. From their perspective it's better to downplay the AETP, and try to keep the monopoly.

Right now, the future variants of the F-35 are going to need the extra engine performance, namely in the cooling department; the current Block 3F systems already draw far more bleed air than originally designed for avionics cooling, and Block 4 will just add to that. Without a new engine, or PW upgrading the F135, there will be some performance and engine life degradation.

The DOD's decision to cancel the F136 engine had everything to do with the budget battles at the time; the DOD simply could not afford to continue development of the F136 engine at the time and afford to purchase enough F-35's within the budget allocated.

ThePointblank wrote:

kitplane01 wrote:

What you wrote about the F-15/F-16 is kind of like "they are good except they're gonna get shot down".

What does "less stealthy but good surviviability" even mean? It sure doesn't mean "successfully runs from missiles" or "can take a missile hit and keep flying".

Low observability messes with the entire kill chain.

In order to successfully kill a target, you must:
- Identify a target;
- Fix the target's location;
- Track the target's movements;
- Target the target with a weapon;
- Engage the target with a weapon, and;
- Assess the results of the attack to see if any follow up is required

This is known by the acronym F2T2EA. You break or interfere with any of the above, you stop the opponent from making a kill. Low observability messes with all aspects of the kill chain, by significantly reducing the chances of success for all aspects of the kill chain.
- If you can't identify a target, you can't engage the target;
- If you can't figure out a target's location, you are just shooting blindly;
- If you can't track the target's movements, you are just shooting blindly at where the target was;
- If you can't aim a weapon at the target, you can't shoot;
- If you don't know the results of your engagement, you don't know if you killed the target

The question wasn't "please tell me how the kill chain works" it was "What does 'less stealthy but good surviviability' even mean?"

Just to be clear, does it mean low observability? Because no one in the history of humanity has ever thought the F-15 was low observable. Maybe the Rafale/Typhoon/Gripen, but the F-15?????

Avatar2go wrote:

kitplane01 wrote:

No one thinks the J-10 or the J-20 are a copy of anything ... and most people believe both are potent fighters. What you wrote was more true in the past than now

The J-10 is a rough copy of the Saab Viggen. The J-20 is more original but copies many elements of the F-22, adapting them to the J-10 canard design.

No.

The J-10 (First flight 1998) is in no way a copy of the Saab Viggen (First flight 1967).

They both have delta wings and canards, but so does every fighter made in Europe in the last 20 years (and they are not copies of the Viggen either). That combination is just one of the standard solutions to making a jet fighter.

The most interesting thing about the Viggen was it's advanced electronics. They were 1967 electronics. The Chinese didn't copy them.

Try this: Name any one thing the Viggen and J-10 share, that's not also shared by 2 other fighters.

LightningZ71 wrote:

While there are competing upgraded engine projects for the F-35, I still see the only real answer as being an upgraded F-135 that has enhanced durability, a modest SFC reduction of, at best, 10%, and perhaps a very slight thrust bump.

I agree. The F135 will simply get a basic engine upgrade. I would consider it the same as a PIP (Performance Improvement Package) in the civilian airliner world. I agree the fuel burn improvement would be at 10% at best. A 5% improvement would still be significant.

For instance the GE9X has a 10% fuel burn improvement over the GE90-115B. Most of that improvement comes from a larger fan which the F-35 can't do. https://simpleflying.com/ge9x-boeing-777x/

The adaptive cycle engine will go into the 6th gen fighter only. I could see this engine having a higher airflow requirement. If you think about the small mouth and big mouth F-16's. Imagine if the F-35 needed to have its inlets widened for increased airflow. That is just one reason why it is a poor choice for the F-35.

The key advantage to the adaptive cycle engine is that it is able to turn into a pure turbojet giving a higher exhaust velocity without having to resort to using an afterburner. This is only needed for "supercruise" or sustained Mach 1.6+ flight. The F-35 and the C variant in particular are not designed to have low supersonic drag. The F-135 already have a fairly high bypass ratio for a fighter jet at 0.57:1. That is good for fuel burn and subsonic cruise.

The USAF 6th gen fighter really needs an engine with totally different characteristics to what the F-35 needs. The sweep angle of the 6th gen fighter points to it having a supercruise speed that will be higher than the F-22. It is also reported to have long range which means a large fuel volume. I definitely could see the aircraft supercruising for large portions of the mission. So the adaptive cycle engine really needs to be optimised for the highest exhaust velocity possible at dry thrust. Fuel efficiency would come second and with the F-35 cruising at subsonic speeds the vast majority of the times it needs fuel efficiency as the number one priority.

The B-21 definitely doesn't need an adaptive cycle engine as it is subsonic. Apparently it uses a two non afterburning F-135 engines. An improved core on the F-135 giving a slight fuel burn improvement would be very useful in the B-21.

kitplane01 wrote:

No.

The J-10 (First flight 1998) is in no way a copy of the Saab Viggen (First flight 1967).

They both have delta wings and canards, but so does every fighter made in Europe in the last 20 years (and they are not copies of the Viggen either). That combination is just one of the standard solutions to making a jet fighter.

The most interesting thing about the Viggen was it's advanced electronics. They were 1967 electronics. The Chinese didn't copy them.

Try this: Name any one thing the Viggen and J-10 share, that's not also shared by 2 other fighters.

This was already answered above. The J-10 was selected for development in 1981, when the Viggen was the only successful canard delta design. It didn't fly for almost 20 years due to engine development problems, which they couldn't copy. The IAI Lavi was also strongly influenced by the Viggen, and the Chinese allegedly admitted they borrowed heavily from that design.

If you want to think otherwise, you are welcome to believe whatever you wish. I have seen enough copying by the Chinese, which has been extensively documented, to think this is a credible assessment.

RJMAZ wrote:

The B-21 definitely doesn't need an adaptive cycle engine as it is subsonic. Apparently it uses a two non afterburning F-135 engines. An improved core on the F-135 giving a slight fuel burn improvement would be very useful in the B-21.

The advantage of the AETP is the ability to switch to a high bypass ratio in cruise, where thrust is less important but the substantial increase in efficiency results in much longer range. Since the B-21 will spend most of it's time in cruise, the AETP having a similar form factor to the F-135, would be a significant advantage. If the AETP program reaches maturity, I would expect it to be considered as a B-21 upgrade.

US Air Force picks five companies to prototype next-gen engines

The U.S. Air Force on Friday awarded contracts worth a total value of about $4.9 billion to five companies to develop prototypes of an adaptive engine for its next-generation fighter jets.

...

Air Force Secretary Frank Kendall told lawmakers in April an adaptive engine, if used in the F-35, would offer substantially increased power that would allow it to operate modernized capabilities.

The Air Force’s decision came about a week after service officials expressed concern that not replacing the F-35′s engine with an adaptive version could lead to the collapse of the advanced propulsion industrial base.

https://www.defensenews.com/air/2022/08 ... n-engines/

Sounds like F-35 could have an adaptive engine mid-2030's.

Edit: mid 2030's onwards.

Avatar2go wrote:

kitplane01 wrote:

No.

The J-10 (First flight 1998) is in no way a copy of the Saab Viggen (First flight 1967).

They both have delta wings and canards, but so does every fighter made in Europe in the last 20 years (and they are not copies of the Viggen either). That combination is just one of the standard solutions to making a jet fighter.

The most interesting thing about the Viggen was it's advanced electronics. They were 1967 electronics. The Chinese didn't copy them.

Try this: Name any one thing the Viggen and J-10 share, that's not also shared by 2 other fighters.

This was already answered above. The J-10 was selected for development in 1981, when the Viggen was the only successful canard delta design. It didn't fly for almost 20 years due to engine development problems, which they couldn't copy. The IAI Lavi was also strongly influenced by the Viggen, and the Chinese allegedly admitted they borrowed heavily from that design.

If you want to think otherwise, you are welcome to believe whatever you wish. I have seen enough copying by the Chinese, which has been extensively documented, to think this is a credible assessment.

I believe the Israeli Kfir is an examples from the 1970s of successful delta wing canard aircraft. By the time of the J-10, delta-and-canard is just a known idea, and using it is not copying the Viggen.

art wrote:

US Air Force picks five companies to prototype next-gen engines

The U.S. Air Force on Friday awarded contracts worth a total value of about $4.9 billion to five companies to develop prototypes of an adaptive engine for its next-generation fighter jets.

...

Air Force Secretary Frank Kendall told lawmakers in April an adaptive engine, if used in the F-35, would offer substantially increased power that would allow it to operate modernized capabilities.

The Air Force’s decision came about a week after service officials expressed concern that not replacing the F-35′s engine with an adaptive version could lead to the collapse of the advanced propulsion industrial base.

https://www.defensenews.com/air/2022/08 ... n-engines/

Sounds like F-35 could have an adaptive engine mid-2030's.

Edit: mid 2030's onwards.

Note that this is the NGEP program mentioned above, for the NGAD. The future of the AETP for the F-35 is still up in the air. As also noted above by others, the upcoming F-35 engine upgrade is unavoidable due to the cooling needs of Block 4. So they will need to decide something on that soon.

Avatar2go wrote:

The advantage of the AETP is the ability to switch to a high bypass ratio in cruise, where thrust is less important but the substantial increase in efficiency results in much longer range. Since the B-21 will spend most of it's time in cruise, the AETP having a similar form factor to the F-135, would be a significant advantage. If the AETP program reaches maturity, I would expect it to be considered as a B-21 upgrade.

It doesn't turn it into a high bypass ratio engine. The engine width is fixed so as the bypass ratio becomes higher the core has to become smaller and overall thrust reduces. Look at the Pratt PW810 it is similar in size to the F135 yet it has two thirds of the dry thrust thanks to the high bypass ratio and smaller core. The PW810 would give a 25+% improvement in specific fuel consumption over the F135 and it is an older engine. But this comes at the expense of LOTS of thrust.

People are drinking the coolaid regarding the AETP. There is no way it can improve SFC by 25% while also increasing thrust. That is 50+ years of engine improvements and improvements are becoming harder. That 25% figure would take into account less afterburner use is required and that depends on the mission profile. If it was a simple subsonic transit at Mach 0.8 I highly doubt the fuel burn improvement would be greater than 5%.

So for the B-21 bomber there is no improvement over simply adding the same turbine tech to the F135 as a PIP or Engine Enhancement Packages (EEP).

Now if you cherry picked a mission profile with a F-35A and it needed to fly the entire mission between Mach 1.3 and 1.4. now the current F135 would need to be on a light afterburner setting for the entire mission. The adaptive cycle engine by comparison would be in "turbojet" mode and probably could sustain that speed without afterburner. It has slightly higher exhaust velocity and power when at 100% dry thrust. The fuel burn improvement here would be massive 30+%. This is where the 25% target comes from.

The F-35C is known for having below average transonic performance similar to the Hornets. The US Navy won't be crusing at Mach 1.3 where the adaptive cycle engine holds an advantage. The adaptive cycle engine won't increase the F-35C combat radius by 25%.

Making the perfect adaptive cycle engine for the F-35 would compromise the performance of 6th gen. Putting an adaptive cycle engine that is fully optimised for 6th gen would be sub optimal for the F-35. Sub optimal to the point where a revised F-135 is superior.

RJMAZ wrote:

Avatar2go wrote:

The advantage of the AETP is the ability to switch to a high bypass ratio in cruise, where thrust is less important but the substantial increase in efficiency results in much longer range. Since the B-21 will spend most of it's time in cruise, the AETP having a similar form factor to the F-135, would be a significant advantage. If the AETP program reaches maturity, I would expect it to be considered as a B-21 upgrade.

It doesn't turn it into a high bypass ratio engine. The engine width is fixed so as the bypass ratio becomes higher the core has to become smaller and overall thrust reduces. Look at the Pratt PW810 it is similar in size to the F135 yet it has two thirds of the dry thrust thanks to the high bypass ratio and smaller core. The PW810 would give a 25+% improvement in specific fuel consumption over the F135 and it is an older engine. But this comes at the expense of LOTS of thrust.

People are drinking the coolaid regarding the AETP. There is no way it can improve SFC by 25% while also increasing thrust. That is 50+ years of engine improvements and improvements are becoming harder. That 25% figure would take into account less afterburner use is required and that depends on the mission profile. If it was a simple subsonic transit at Mach 0.8 I highly doubt the fuel burn improvement would be greater than 5%.

So for the B-21 bomber there is no improvement over simply adding the same turbine tech to the F135 as a PIP or Engine Enhancement Packages (EEP).

Now if you cherry picked a mission profile with a F-35A and it needed to fly the entire mission between Mach 1.3 and 1.4. now the current F135 would need to be on a light afterburner setting for the entire mission. The adaptive cycle engine by comparison would be in "turbojet" mode and probably could sustain that speed without afterburner. It has slightly higher exhaust velocity and power when at 100% dry thrust. The fuel burn improvement here would be massive 30+%. This is where the 25% target comes from.

The F-35C is known for having below average transonic performance similar to the Hornets. The US Navy won't be crusing at Mach 1.3 where the adaptive cycle engine holds an advantage. The adaptive cycle engine won't increase the F-35C combat radius by 25%.

Actually, the data that the AETD engines are performing significantly better than the existing engines is from the ongoing test program. GE's engine met and exceeded performance targets:

https://aviationweek.com/defense-space/ ... ce-targets

Results from test runs of the first XA100—which began in GE’s high-altitude test cell in Evendale, Ohio, on Dec. 22 and continued through late March—have exceeded expectations according to David Tweedie, GE Edison Works’ general manager for Advanced Combat Engines.

“We hit all of our primary test objectives,” Tweedie said. “The engine behaved right along with our pre-test predictions and was very consistent with the program goals. We were able to demonstrate the two different modes of the engine and the ability to seamlessly transition between those two modes.”

Designed to run separately to the conventional core air and lower pressure bypass flows, the additional third stream can be redirected to provide increased thrust during combat or better fuel efficiency during cruise conditions. [bT]he AETP goals aimed to improve thrust and fuel efficiency by 10% and 25% respectively compared to a 2015 state-of-the-art fighter engine. “Not only are we meeting that, we’re actually exceeding that pretty much everywhere in the flight envelope—and in a few places—up to 20% [more thrust],” Tweedie said. “We are very happy with where we are from thrust in terms of over-delivering versus the program requirement.”[/b]

“When you translate that to what it means to the platform, it’s 30% more range or 50% more loiter time depending on how you want to utilize that fuel burn improvement. It’s a significant increase in acceleration and combat capability with the increased thrust,” he said.

Another crucial parameter for the test program is the effectiveness of using heat exchangers in the third stream for thermal management—a growing challenge, particularly for low-observable, advanced combat aircraft with power-hungry sensors, systems and weapons. “We see a significant increase in capability there [with] up to two times mission systems growth enabled by the [improved] thermal management,” Tweedie said.

GE is using some fairly advanced technologies in the XA100 engine; they are talking about extensive use of ceramic matrix composites in the construction of hot section of the engine, along with its new three stream architecture to reduce the thermal IR signature and significantly improved cooling capacity. This increases the amount of bleed air and horsepower extraction the engine can provide to the airframe and the capacity to act as a heat sink.

The current F135 is capable of providing the cooling bleed flow for Block 4, but has to run longer at high thermal conditions than the original specification, to the detriment of hot section life. Pratt's proposed upgrade improves compressor efficiency for lower thermals and SFC, and improves hot section component durability under the Block 4 bleed conditions, but they can only do so much with the existing design.

RJMAZ wrote:

It doesn't turn it into a high bypass ratio engine. The engine width is fixed so as the bypass ratio becomes higher the core has to become smaller and overall thrust reduces.

Look at the Pratt PW810 it is similar in size to the F135 yet it has two thirds of the dry thrust thanks to the high bypass ratio and smaller core. The PW810 would give a 25+% improvement in specific fuel consumption over the F135 and it is an older engine. But this comes at the expense of LOTS of thrust.

People are drinking the coolaid regarding the AETP. There is no way it can improve SFC by 25% while also increasing thrust. That is 50+ years of engine improvements and improvements are becoming harder. That 25% figure would take into account less afterburner use is required and that depends on the mission profile. If it was a simple subsonic transit at Mach 0.8 I highly doubt the fuel burn improvement would be greater than 5%.

So for the B-21 bomber there is no improvement over simply adding the same turbine tech to the F135 as a PIP or Engine Enhancement Packages (EEP).

The AETP engine does increase the bypass ratio, but the form factor restriction means it must do so by adding a third pressurized air steam, rather than increasing the diameter of the fan, as is typical for turbofans. Thus the extra fan area is added in the form of in-line stages, rather than radially as with a turbofan.

This is the difficulty of installation in the F-35B, the space required for the extra stages is taken up by the lift fan. In some sense, the F-35 AETP feasibility is only possible because the overall F-35 design reserved room for that fan.

AETP would be a suitable upgrade for the B-21, as I said if it reaches maturity and is not surpassed by the NGEP program. Also assuming it would fit, which we have no way to judge at present.

As ThePointBlank noted, the performance increases of the AETP are real and documented. They are not disputed, but won't be the only consideration in the choice of F-35 upgrades.

My own view is that the F-135 upgrade is a better solution, but I'm sure I don't have the requisite knowledge of all the factors. We'll have to see what DoD decides. As ThePointBlank said, the upgrade would be the limit for pushing the F-135 design, so that's another factor to consider.

Avatar2go wrote:

RJMAZ wrote:

It doesn't turn it into a high bypass ratio engine. The engine width is fixed so as the bypass ratio becomes higher the core has to become smaller and overall thrust reduces.

Look at the Pratt PW810 it is similar in size to the F135 yet it has two thirds of the dry thrust thanks to the high bypass ratio and smaller core. The PW810 would give a 25+% improvement in specific fuel consumption over the F135 and it is an older engine. But this comes at the expense of LOTS of thrust.

People are drinking the coolaid regarding the AETP. There is no way it can improve SFC by 25% while also increasing thrust. That is 50+ years of engine improvements and improvements are becoming harder. That 25% figure would take into account less afterburner use is required and that depends on the mission profile. If it was a simple subsonic transit at Mach 0.8 I highly doubt the fuel burn improvement would be greater than 5%.

So for the B-21 bomber there is no improvement over simply adding the same turbine tech to the F135 as a PIP or Engine Enhancement Packages (EEP).

The AETP engine does increase the bypass ratio, but the form factor restriction means it must do so by adding a third pressurized air steam, rather than increasing the diameter of the fan, as is typical for turbofans. Thus the extra fan area is added in the form of in-line stages, rather than radially as with a turbofan.

This is the difficulty of installation in the F-35B, the space required for the extra stages is taken up by the lift fan. In some sense, the F-35 AETP feasibility is only possible because the overall F-35 design reserved room for that fan.

AETP would be a suitable upgrade for the B-21, as I said if it reaches maturity and is not surpassed by the NGEP program. Also assuming it would fit, which we have no way to judge at present.

As ThePointBlank noted, the performance increases of the AETP are real and documented. They are not disputed, but won't be the only consideration in the choice of F-35 upgrades.

My own view is that the F-135 upgrade is a better solution, but I'm sure I don't have the requisite knowledge of all the factors. We'll have to see what DoD decides. As ThePointBlank said, the upgrade would be the limit for pushing the F-135 design, so that's another factor to consider.

I think the bigger issue with the AETP engine for the F-35B isn't the lift fan, but balancing the extra weight (both AETP engines are heavier than the F135), and the extra power the engine puts out. Remember that some of the high pressure fan air is used for the roll posts, they will need to be able to coordinate the thrust from the front lift fan and engine exhaust, while keeping weight manageable and balanced for the entire system. It's theoretically possible to do this, but would require a lot of engineering effort to do so.

ThePointblank wrote:

I think the bigger issue with the AETP engine for the F-35B isn't the lift fan, but balancing the extra weight (both AETP engines are heavier than the F135), and the extra power the engine puts out. Remember that some of the high pressure fan air is used for the roll posts, they will need to be able to coordinate the thrust from the front lift fan and engine exhaust, while keeping weight manageable and balanced for the entire system. It's theoretically possible to do this, but would require a lot of engineering effort to do so.

Agreed on all counts. The PW version of AETP has the extended stages in front and doesn't fit. The GE version fits but wasn't designed for the F-35B front power take-off for the lift fan, or the bleed-air take-off for roll-post. GE says they are looking into that now. If they are successful, that could swing the decision more in favor of the AETP.

https://aviationweek.com/shownews/farnb ... tion-f-35b

Unless GE can work some materials science and mechanical wizardry, there's just not a way of putting an AETP engine in the F-35 that is enough of an improvement and also financially viable enough to justify its existence. A PIP to the existing F-135 that takes advantage of the last two+ decades of advances in materials science and turbine design as well as even higher precision manufacturing seems the more successful route for the whole program. Just getting a modest improvement, combined with a modest dry thrust improvement coupled with longer maintenance intervals would go a LONG way towards making the plane markedly better. Any increase in unrefueled range is a big deal for carrier aircraft and increased take off payload from increased thrust for the B helps as well.

I can see the A model potentially getting a different engine due to having a completely different supply chain, but even then, its going to be an expensive program and has to justify itself over a likely more modestly proced alternative that also helps. Where the AF calculus may be different is that, for them, it makes the F-35 more viable as a stand in for the F-22, which may have a shortened life if its sustainment costs can't come under control.

LightningZ71 wrote:

Unless GE can work some materials science and mechanical wizardry, there's just not a way of putting an AETP engine in the F-35 that is enough of an improvement and also financially viable enough to justify its existence. A PIP to the existing F-135 that takes advantage of the last two+ decades of advances in materials science and turbine design as well as even higher precision manufacturing seems the more successful route for the whole program. Just getting a modest improvement, combined with a modest dry thrust improvement coupled with longer maintenance intervals would go a LONG way towards making the plane markedly better. Any increase in unrefueled range is a big deal for carrier aircraft and increased take off payload from increased thrust for the B helps as well.

I can see the A model potentially getting a different engine due to having a completely different supply chain, but even then, its going to be an expensive program and has to justify itself over a likely more modestly proced alternative that also helps. Where the AF calculus may be different is that, for them, it makes the F-35 more viable as a stand in for the F-22, which may have a shortened life if its sustainment costs can't come under control.

The XA100 engine is designed to exceed 45kN of thrust, which is already 5kN higher than the F135, while providing more bypass air, generator power and better fuel economy and engine life.

A PIP F135 won't solve the problems of increased electrical generation and cooling requirements without impacting engine performance.

One of the biggest things in the F35, and probably the biggest single thing that has caused pain, is the open architecture avionics.

For aircraft 10, 20, or even 50 years from now, that will have the biggest unseen impact.

To address the OP, that alone will make it feasible for the F35 to stay competitive. The ability to continually and rapidly upgrade sensors, weapons, engines, etc. while retaining a LO airframe will have a huge impact.

Such an open avionics system will also make it simpler to make airframe changes as there will be less involved to change all the stuff that gets attached. You can already see an impact of this with the B21 where they took large parts of the F35 and basically plugged them into a purpose built airframe. Another example is the EOTS upgrade where the new sensors provide much better performance and can basically plug into existing airframes with a software upgrade.

ThePointblank wrote:

The XA100 engine is designed to exceed 45kN of thrust, which is already 5kN higher than the F135

The F-135 has already done 50klb of thrust back in 2010. https://www.f-16.net/forum/viewtopic.php?t=16265

Durability is the key. The F-135 is derated significantly to reduce maintenance costs and shop visits. All turbofan manufacturers have the ability to trade between durability and maximum power. For instance the F414 had the EPE or EDE option. The Russian engines trade significant service life to have similar thrust to weight.

We even have increased power for war use.
https://en.m.wikipedia.org/wiki/War_emergency_power

The adaptive cycle engines might be producing high power in testing but I highly doubt they have the durability yet.

ThePointblank wrote:

while providing more bypass air

How do you know the XA100 has a higher bypass ratio?

Bypass ratios from Wikipedia.
F-22 F119 = 0.30:1
Super Hornet F414 = 0.25:1
Eurofighter EJ200 = 0.4:1
Rafale M88 = 0.3:1

Now the F-135 bypass ratio is much higher at 0.57:1. More bypass air generally gives improved fuel efficiency at subsonic cruise. It also gives more cool air around the engine. As bypass air is slower it gives lower overall exhaust avelocity at 100% military/dry power making it worse for supercruising.

With the 6th gen fighter supercruising would be a priority so it needs high exhaust velocity at 100% military/dry power. It is likely with the third stream closed the XA100 will have a very low bypass ratio like the F414 at 0.25:1. The third stream might only double the bypass air to 0.5:1 in total. This would still have less bypass air compared to the F-135.

The biggest single upgrade, outside of a series of software module changes/upgrades/maintainability stuff which is boring for us to discuss, would to me be the integration of a directed energy weapon. This again would benefit from a maxed out electrical capacity from the engine, imho.

texl1649 wrote:

The biggest single upgrade, outside of a series of software module changes/upgrades/maintainability stuff which is boring for us to discuss, would to me be the integration of a directed energy weapon. This again would benefit from a maxed out electrical capacity from the engine, imho.

I really really doubt there is enough space to fit a directed laser beam and it's aiming aparatus.

Also, the lasers we have now have to dwell on the target for multiple seconds. It's not like in the movie at all.

GE is now pitching their XA100 adaptive cycle engine to power the F-35B:

https://www.thedrive.com/the-war-zone/x ... -f-35b-too

There is additional bits in the article about the benefits of adaptive cycle engines as well.

ThePointblank wrote:

GE is now pitching their XA100 adaptive cycle engine to power the F-35B:

https://www.thedrive.com/the-war-zone/x ... -f-35b-too

There is additional bits in the article about the benefits of adaptive cycle engines as well.

For now at least, this is a feasibility study. If they can demonstrate a working version of this engine for the F-35B, that would be great.

The major hump for the AETP F-35 program, is getting all the services and partner nations on board, from the beginning. That's the only way it will be affordable. So GE is bending over backwards to show it can be a universal engine, for all models and services.

The alternative approach would be a mixed engine fleet, but the JPO has expressed reluctance to go down that path, both for the F-136 and now again with AETP.

So GE has their work cut out for them. If they can show working versions for the F-35 C and B models in the next year, that will boost the program. Then the issue just comes down to cost vs performance. Roughly 3 times the cost vs perhaps a 20% gain, over the competing F-135 upgrade.

Avatar2go wrote:

ThePointblank wrote:

GE is now pitching their XA100 adaptive cycle engine to power the F-35B:

https://www.thedrive.com/the-war-zone/x ... -f-35b-too

There is additional bits in the article about the benefits of adaptive cycle engines as well.

For now at least, this is a feasibility study. If they can demonstrate a working version of this engine for the F-35B, that would be great.

The major hump for the AETP F-35 program, is getting all the services and partner nations on board, from the beginning. That's the only way it will be affordable. So GE is bending over backwards to show it can be a universal engine, for all models and services.

The alternative approach would be a mixed engine fleet, but the JPO has expressed reluctance to go down that path, both for the F-136 and now again with AETP.

So GE has their work cut out for them. If they can show working versions for the F-35 C and B models in the next year, that will boost the program. Then the issue just comes down to cost vs performance. Roughly 3 times the cost vs perhaps a 20% gain, over the competing F-135 upgrade.

Per the article, a XA100 engine for the F-35A and C would be 100% parts identical, save the requirement for additional testing for the F-35C. GE is also aiming for the engine to be a seamless replacement for the F135 engine.

But it seems like there is some reception amongst the F-35B users and the F-35 JPO to see if the XA100 engine will fit in the F-35B; all the users have indicated they would like to see more power, range, fuel efficiency, and reliability.

ThePointblank wrote:

Per the article, a XA100 engine for the F-35A and C would be 100% parts identical, save the requirement for additional testing for the F-35C. GE is also aiming for the engine to be a seamless replacement for the F135 engine.

But it seems like there is some reception amongst the F-35B users and the F-35 JPO to see if the XA100 engine will fit in the F-35B; all the users have indicated they would like to see more power, range, fuel efficiency, and reliability.

For the F35-C, they need to demonstrate marine & carrier environment compatibility. They have not yet built an engine with those features. They have shown that they can make it fit, with virtual 3D design and engineering drawings.

For the F-35B they are just in the initial feasibility study. It too will need the marine environment features, as well as other significant modifications.

As I mentioned, GE is trying to get out in front of the program negatives, since it's apparent the decision will be made in the next year. Probably before they have time to fully demonstrate these capabilities.

The competing F-135 upgrade option is pretty much fully formed and ready to go. So GE needs to show they can be ready with the same applicability.

TWZ articles tend to either cheerlead or trash defense programs. This one is a cheerlead. That's great, and the program has undeniable potential, even apart from the F-35. But the JPO will be reviewing it in the terms I tried to outline.

As also mentioned, a lot depends on buy-in. I think if the services and partner nations are asking for this engine, and agree to the costs, it will happen. But without that, JPO will gravitate to the less expensive and more certain F-135 upgrade.