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LightningZ71
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Re: USAF PCA and other 6th gen fighters

Mon Jun 29, 2020 3:09 pm

Adding to Ozair's statement, with regard to the B-52, the only reason that an engine swap is even being discussed there is that supporting the TF-33 is getting more and more difficult as the platform ages. Going to a modern engine will certainly bring greater efficiency with respect to fuel and emissions, but the B-52 is not effectively limited in its operational capability due to a lack of range from a closest friendly refueling point point of view. For the change to be deemed worthy, it needs to provide enough savings for the lifetime of the engines on the wing from reduced maintenance costs and fuel consumption savings (more efficient engines use less fuel, requiring less fuel for equivalent distances flown) requiring lower take off weights (which reduce wear and tear on the frame, admittedly a very minor factor) and fewer expensive aerial refuelings, against the cost of purchasing all new engines, spares, support equipment unique to those engines, training existing maintainers on the new engines, overhauling the cockpit, adding digital engine management systems, retraining the air crews, going through the design work, purchasing the engine control systems, running the new wiring, testing all of the individual components, and requalifying the whole airframe with the new engines. None of that is free, and much of it costs lots and lots of man hours, which also isn't free. After all of that, what have you gained for the B-52 operationally? It can fly a bit farther on a full load of fuel, but the extra range wasn't really a need before. IT won't be able to carry MORE bombs as it was already at structural capacity as it stands. It won't be able to go appreciably faster or higher, as that's more of an airframe thing and not an engine power thing. It can already loiter longer than you really want a crew to be loitering. All in all, its not an appreciably better bomber from the standpoint of being a bomber.

The F-35 is a different story. There is a noted need for more electrical power. It stands to gain substantially from greater engine efficiency as it allows it to fly farther without requiring external tanks, and is especially valuable for the C given naval ranges, and the B, given its limitations due to the extra mass of the SVTOL equipment. It also stands to gain in maneuverability, as it will have more engine thrust to help overcome the loss of energy it experiences in high G turns (more valuable in the A as it is rated for higher G turns).

The F-18 is kind of in the middle. Greater engine thrust can make take offs safer as it will have more thrust available in a single engine failure on take off, and will have more thrust available in the case of an unexpectedly low power cat launch. The greater thrust will allow it to carry more fuel aloft to allow for greater range with the same bomb load, though, you do run into other limitations there. It won't have a much higher top speed. IT will be able to cruise slightly faster for the same current fuel burn, or cruise at the current speed for longer. Coupled with CFTs, though, it can make a wider variety of missions available to it without requiring drop tanks. It's not transformative, just slightly additive. And, that then calls for the next question, is it worth it? Or, do you spend that money elsewhere, like on autonomous tanker drones that can provide for aerial refueling for a handful of fighters to give them essentially the same as above capabilities, while also being able to refuel F-35s, making them more capable as well?

Engine upgrades when you were moving from old, low pressure low bypass turbofans and turbojets, to modern high bypass turbofans, like on the KC-135, or the B-52 moving to the TF-33s in production at the end of the line, make a lot of sense. The improvements are vast, and the capabilities of the craft greatly enhanced. Incremental upgrades, in the order of a few tens of %, take a lot more convincing and have much, much longer pay-off times.
 
RJMAZ
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Re: USAF PCA and other 6th gen fighters

Tue Jun 30, 2020 8:44 am

744SPX wrote:
I would like to believe the F-35 will be getting the AETP engine, but based on recent AF and Navy acquisition history I don't see it happening.
Since the installation of upgraded engines on the F-14, F-15E, F-16 and Legacy Hornets in the late 80's/early 90's, both the Navy and AF have refused to purchase improved engines for their aircraft despite their availability from GE and Pratt and this in the face constant weight gain and higher drag on all fighter aircraft..

Actually this is completely opposite from the truth. Every single fighter you mentioned got newer engines fitted.

The F-14's went from Pratt TF30's to GE F110.
The Hornet went from the F404-GE-400 to the 402 which was a huge upgrade in thrust and durability.
The newest F-16's in the USAF have way more thrust than the early builds and they even got an option for a second GE engine after 10 years of service. New international F-16 customers even have a third engine to chose from.

I would go as far as saying every US fighter in history that was in production for more than 20 years got a new engine.

I never said that the USAF would re-engine existing F-35's. This would be silly considering the engine would still have thousands of flight hours left. In 10 years time it is a near certainty that the F-35 rolling off the production line will have a different engine to the one fitted today. It will have improved thrust and fuel burn. The F-35 will be in production for 40+ years so it will probably even get a third engine just like the F-16.
 
744SPX
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Re: USAF PCA and other 6th gen fighters

Tue Jun 30, 2020 9:21 pm

Yes, they all did get newer engines fitted, but my point was it was 30 years ago and all these aircraft have continued to gain weight while thrust upgrades have been available for a very long time. The US F-15E and F-16 fleet could have been fitted with 32-34k versions of the F100/F110 20 years ago. The Super Hornet has received no thrust upgrades despite the fact that it needs it more than the C/D ever did. The F-15C never got a thrust upgrade.
 
Ozair
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Re: USAF PCA and other 6th gen fighters

Tue Jun 30, 2020 10:43 pm

744SPX wrote:
Yes, they all did get newer engines fitted, but my point was it was 30 years ago and all these aircraft have continued to gain weight while thrust upgrades have been available for a very long time. The US F-15E and F-16 fleet could have been fitted with 32-34k versions of the F100/F110 20 years ago. The Super Hornet has received no thrust upgrades despite the fact that it needs it more than the C/D ever did. The F-15C never got a thrust upgrade.

What is missing is your justification that the extra thrust is needed. You have claimed the F-15 and 16 fleet need the extra thrust but the evidence isn’t present to support that. Sure the aircraft have increased marginally in weight but additional top end thrust likely doesn’t provide the performance gains you think it does.

Again if you consider the time the aircraft will spend in that maximum thrust zone, likely just tens of seconds out of a total flight of one to two hours it just isn’t worth the upgrade cost. GE doesn’t list a dry thrust for the F110-GE-132 but the F100-PW-229A has the same dry thrust as the standard 229 with only the wet thrust increased to 32.5k. (specs for both engines here, http://www.jet-engine.net/miltfspec.html)

Same for the SH, to claim it needs more thrust you need to provide a statement from the USN asking for it. With the Classic Hornet the Kuwaitis paid for the thrust improvements to the F404 that the USN subsequently benefitted from, the USN didn’t pay for that work themselves. Additionally Kuwait have ordered the SH but haven’t asked or are paying GE for an engine upgrade for the aircraft.
 
744SPX
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Re: USAF PCA and other 6th gen fighters

Wed Jul 01, 2020 2:33 pm

I get what you are saying about cost benefit, I'm just always of the mind that you can't have too much thrust. Also, considering how much DOD money is uselessly thrown away, I think thrust upgrades are more than justifiable.

Also, I'm pretty sure both the F100 and F110 32k versions have proportionately increased dry thrust, between 19,000 and 20,000 lbs I believe. Both engines have higher airflow fans so its not just about afterburner thrust. Also, the F100-232/229-EPE use F-119 tech not just for more power but also more fuel efficiency.
 
Ozair
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Re: USAF PCA and other 6th gen fighters

Wed Jul 01, 2020 10:27 pm

744SPX wrote:
I get what you are saying about cost benefit, I'm just always of the mind that you can't have too much thrust. Also, considering how much DOD money is uselessly thrown away, I think thrust upgrades are more than justifiable.

Again, the time spent in that thrust region is so small the improvement is minuscule and aerodynamics plays a far more significant role than the additional thrust. For example if you take the F-16C powered by the F100-PW-129 the difference from MIL to Max AB on turning agility is negligible. A Max AB jet clean at 22,000lbs has only a .5 degree better turn rate than the same jet at MIL. So despite the addition of over 60% more thrust the pilot gets only a 2.5% better turn rate. That turn rate advantage from using Max AB also reduces further with weight gain of the aircraft. At a representative operational configuration weight of 26,000lbs the turn rate with Max AB is only 0.3 degrees better. That turn rate advantage is now within the margin of pilot skill and not airframe performance.

Above numbers are taken from this source doc https://info.publicintelligence.net/HAF ... lement.pdf using 10,000ft MIL and Max AB charts. Start at page A8-33.

Where the higher thrust versions improve performance is on take-off, acceleration and energy retention but I expect, given the minimal agility differences, that a lower thrust F110/F100 at Max AB is going to also provide essentially the same advantages except for take-off where the thrust will really matter. For the UAE, the only user of the F110-GE-132, who have only three AAR tankers and yet nearly 150 fighter aircraft being able to take off in hot and dry conditions with greater weights is worth the additional sustainment cost and likely fuel use of the 32k engine. The USAF doesn’t have that issue.

744SPX wrote:
Also, I'm pretty sure both the F100 and F110 32k versions have proportionately increased dry thrust, between 19,000 and 20,000 lbs I believe. Both engines have higher airflow fans so its not just about afterburner thrust. Also, the F100-232/229-EPE use F-119 tech not just for more power but also more fuel efficiency.

Did you actually read the source link I posted above on engine specs? There is no dry thrust or SFC value listed for the F110-GE-132 but the F100-PW-229A lists the same dry thrust as the 229. No SFC for either of the 32k versions, 132 and 229A, but for the F100 the SFC is listed across a number of versions, all within a small variance of values (0.720 to 0.735). I highly doubt the 32k versions of both engines have a significant enough difference in SFC to their lesser powered counterparts.
 
Ozair
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 9:46 am

Well this is quite the surprise. Apparently the USAF have already built and flown a prototype of the NGAD, with the likelihood there may be additional prototypes from other manufacturers soon to fly as well. No further info on size, range, engine etc but certainly surprising. If this really is what the Digitial Century series will foster then look out every single other fighter program including F-35. There won't be a future for Tempest or FCAS outside their principal nations, and perhaps even none within, if the US can do this type of development so quickly.

The US Air Force has built and flown a mysterious full-scale prototype of its future fighter jet


The U.S. Air Force has secretly designed, built and flown at least one prototype of its enigmatic next-generation fighter jet, the service’s top acquisition official confirmed to Defense News on Sept. 14.

The development is certain to shock the defense community, which last saw the first flight of an experimental fighter during the battle for the Joint Strike Fighter contract 20 years ago. With the Air Force’s future fighter program still in its infancy, the rollout and successful first flight of a demonstrator was not expected for years.

“We’ve already built and flown a full-scale flight demonstrator in the real world, and we broke records in doing it,” Will Roper told Defense News in an exclusive interview ahead of the Air Force Association’s Air, Space and Cyber Conference. “We are ready to go and build the next-generation aircraft in a way that has never happened before.”

...

https://www.defensenews.com/breaking-ne ... ghter-jet/
 
DigitalSea
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 2:07 pm

Curious as to why the USAF felt the need to disclose this unless China 6th Gen Developments are farther along than the public knows.
 
LightningZ71
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 3:25 pm

The ability to do full digital prototyping in a virtual wind tunnel and then quickly turn around and build a working, full scale prototype with production quality parts produced from 3D printers of various sizes and types (including ones designed to work with unusual materials) is making a major impact on product development across the aerospace world. IT can not be overstated how impactful the combination of those two factors is in both reducing the time from concept to flight AND the cost of the whole enterprise. What once would have taken almost a decade can be done in months, and what once would have taken hundreds of engineers working that entire time can be done with a much lower headcount. It certainly isn't perfect, but it'll get you something that's both functional and a lot closer to production ready in dramatically shorter amounts of time.

And, this doesn't mean that there aren't a ton of issues to still work out once it's actually sitting there, in the hangar, all built and flyable. So much remains to be done. What you usually get is something that is full scale, aerodynamically nearly complete, and is useful for testing a lot of the final production parts with.
 
tomcat
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 4:00 pm

LightningZ71 wrote:
The ability to do full digital prototyping in a virtual wind tunnel and then quickly turn around and build a working, full scale prototype with production quality parts produced from 3D printers of various sizes and types (including ones designed to work with unusual materials) is making a major impact on product development across the aerospace world.


That's good news for the airframe development but then what about the systems and equipment's of the said airframe? It's usually them (and sometimes the engine) that are ever delaying the entry into service of new fighter jets.
 
aumaverick
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 4:10 pm

tomcat wrote:
LightningZ71 wrote:
The ability to do full digital prototyping in a virtual wind tunnel and then quickly turn around and build a working, full scale prototype with production quality parts produced from 3D printers of various sizes and types (including ones designed to work with unusual materials) is making a major impact on product development across the aerospace world.


That's good news for the air frame development but then what about the systems and equipment's of the said air frame? It's usually them (and sometimes the engine) that are ever delaying the entry into service of new fighter jets.


That's part of the overall impact in rapid prototyping as part of the Digital Century Series. Not only is the design, testing, and fabrication of the air frame now rapid, but so is the development, design, and integration testing of the systems and avionics. This has been proven as part of the development of the T-7 and the B-21, with the digital system components, avionics, and electronics all designed and developed via agile methodology all before being put into an actual air frame.
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 5:03 pm

tomcat wrote:
That's good news for the airframe development but then what about the systems and equipment's of the said airframe? It's usually them (and sometimes the engine) that are ever delaying the entry into service of new fighter jets.


Problems with system integration is different than airframe integration. Systems are often modular and can be modified much more quickly.

Airframe manufacturing involves enormous long lead fabrication which may encompass a couple of years for some parts. Reducing this flow would allow structures to be in the same ball park as systems in terms of turnaround adaptability.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
tomcat
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 5:39 pm

bikerthai wrote:
tomcat wrote:
That's good news for the airframe development but then what about the systems and equipment's of the said airframe? It's usually them (and sometimes the engine) that are ever delaying the entry into service of new fighter jets.


Problems with system integration is different than airframe integration. Systems are often modular and can be modified much more quickly.

Airframe manufacturing involves enormous long lead fabrication which may encompass a couple of years for some parts. Reducing this flow would allow structures to be in the same ball park as systems in terms of turnaround adaptability.

bt


I can follow you up to a point and I may be missing something but I'm under the impression that if recent aircraft like the F-35, the Rafale, the Eurofighter and even the A400M took forever to reach their initial operational readiness (after the first flight milestone) it was more due to the slow progress on systems maturity rather than airframe evolutions (which may have occurred but they haven't hampered reaching the operational readiness). Even beyond the initial operational readiness, the systems are still being developed for years before reaching the capabilities that were announced in the original brochure.

I'm fully aware of the long lead times involved in an airframe development and if this alone can be improved I find it a great achievement.

But then if the point is actually to develop an airframe to embed sort of off the shelf systems then I can fully appreciate the benefits of having a reduced lead time for the airframe development.
 
aumaverick
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 7:01 pm

tomcat wrote:
bikerthai wrote:
tomcat wrote:
That's good news for the airframe development but then what about the systems and equipment's of the said airframe? It's usually them (and sometimes the engine) that are ever delaying the entry into service of new fighter jets.


Problems with system integration is different than airframe integration. Systems are often modular and can be modified much more quickly.

Airframe manufacturing involves enormous long lead fabrication which may encompass a couple of years for some parts. Reducing this flow would allow structures to be in the same ball park as systems in terms of turnaround adaptability.

bt


I can follow you up to a point and I may be missing something but I'm under the impression that if recent aircraft like the F-35, the Rafale, the Eurofighter and even the A400M took forever to reach their initial operational readiness (after the first flight milestone) it was more due to the slow progress on systems maturity rather than airframe evolutions (which may have occurred but they haven't hampered reaching the operational readiness). Even beyond the initial operational readiness, the systems are still being developed for years before reaching the capabilities that were announced in the original brochure.

I'm fully aware of the long lead times involved in an airframe development and if this alone can be improved I find it a great achievement.

But then if the point is actually to develop an airframe to embed sort of off the shelf systems then I can fully appreciate the benefits of having a reduced lead time for the airframe development.


You are correct in the past history of systems maturity vs. air frame maturity and operational readiness. The difference between those past platforms and now is the standardization of the software and the integration points. Whereas the F-22 and F-35 were both very advanced air frames, their systems and electronics were not, even to the point that the two aircraft could not communicate data in the same language (I'm generalizing here) due to the technology advancements that occurred between the development of both platforms.

Now, manufacturers are better adapted to deploying technology digitally. That is to say, they can simulate the systems, from avionics to aircraft and mission systems, in a sandbox, identify changes to the code on the fly, and apply iterative changes more quickly before applying the technology in the real world. This is allows for system maturity much faster with the goal of avoiding the growing pains experienced in the past.
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LightningZ71
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 7:02 pm

You've essentially got the gist of it there. Having an early, full scale demonstrator that is of the relevant dimensions with respect to internal equipment plans is a valuable asset in accelerating the development of the installed equipment. Other measures are being taken to accelerate other aspects of the program to be sure, and the flight demonstrator can pay dividends with that.
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 7:14 pm

tomcat wrote:
F-35, the Rafale, the Eurofighter and even the A400M took forever to reach their initial operational readiness (after the first flight milestone) it was more due to the slow progress on systems maturity rather than airframe evolutions


System maturity is broad concept. Even the F-35 was hampered by the need to develope and manufacture high temperature composites. Those types of material advancements can not be acellerated by "digital technology".

The time between first flight and initial readiness is another story. That has to do with mow mature the system is by the time of first flight so that going full production can be a little smoother.

I'm focusing more of the time frame between a system is selected/finalized to the time of first flight. Compressing that time line will allow for quicker feedback and subsequent changes.

We can all agree that the digital revolution has already aide with the development stage with rapid prototyping. It's this next step in "high speed" manufacturing that will help compress the middle part.

Which bring me to this question. Apparently this news of the latest prototype flying make me curios on what manufacturing technology they are using to get the frame so quickly. Have they been building the frame for a while now? Or have they tapped into something similar to what Boeing is doing with the T-7 to speed up the process? My first guess would be something from the Skunk Works. Does LM have some process similar to what Boeing is doing?

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
Planeflyer
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 9:52 pm

Colorectal me if I’m wrong but in the past hasn’t the airframe itself been a long lead time item especially on stealth aircraft?
 
RJMAZ
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 10:00 pm

Ozair wrote:
Well this is quite the surprise. Apparently the USAF have already built and flown a prototype of the NGAD, with the likelihood there may be additional prototypes from other manufacturers soon to fly as well. No further info on size, range, engine etc but certainly surprising. If this really is what the Digitial Century series will foster then look out every single other fighter program including F-35. There won't be a future for Tempest or FCAS outside their principal nations, and perhaps even none within, if the US can do this type of development so quickly.

You act surprised. This is simply the new design technology at work. I have mentioned this many times on this forum but it seems to fall on deaf ears. Many can't comprehend the level of cost and time reduction. I worked in aerospace at what I consider a very high level and have seen it first hand.

The examples where I stated the F-35 could have been done at 10% of the cost is not only true but probably conservative. As you said in the other post:

Ozair wrote:
10% of the development cost... Sorry mate that is bonkers.


Picture sending a spaceship today to the next solar system. It might take 15,000 years to get there. But in 100 years time we might be able to send a faster spaceship that takes only 1,000 years to get there. The longer you wait the faster it becomes. This is why so much money has been silently spent on design technology. This is the 21st century advantage.
 
RJMAZ
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Re: USAF PCA and other 6th gen fighters

Wed Sep 16, 2020 10:15 pm

tomcat wrote:
but I'm under the impression that if recent aircraft like the F-35, the Rafale, the Eurofighter and even the A400M took forever to reach their initial operational readiness (after the first flight milestone) it was more due to the slow progress on systems maturity rather than airframe evolutions.

Consider the F-35 systems like a phone operating system with the pre-installed apps. All they need to do is install the 6th gen fighter app and the new avionics are complete. Nearly all the work has been.

Engines can also be modelled in digital and problems found. No doubt every part of the engine can be tested for air flow, heat and strength in a digital environment.

I got a good laugh back in 2008 when I watched Tony Stark produces his Iron Man suite at his home. I am not laughing now.

Planeflyer wrote:
Colorectal me if I’m wrong but in the past hasn’t the airframe itself been a long lead time item especially on stealth aircraft?

It was. The physical airframe is the now the easiest part by a very long way. It makes sense to just use two off the shelf F135 engines and the F-35 avionics. The whole 6th gen prototype could go from a blank piece of paper to first flight of a near production ready prototype in under 2 years. They will no doubt just scale up number of AESA radar modules. The production engine will no doubt be an improved F-35 engine that will eventually be fitted to the F-35 in later production blocks.
 
Ozair
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 12:34 am

RJMAZ wrote:
Ozair wrote:
Well this is quite the surprise. Apparently the USAF have already built and flown a prototype of the NGAD, with the likelihood there may be additional prototypes from other manufacturers soon to fly as well. No further info on size, range, engine etc but certainly surprising. If this really is what the Digitial Century series will foster then look out every single other fighter program including F-35. There won't be a future for Tempest or FCAS outside their principal nations, and perhaps even none within, if the US can do this type of development so quickly.

You act surprised. This is simply the new design technology at work. I have mentioned this many times on this forum but it seems to fall on deaf ears. Many can't comprehend the level of cost and time reduction. I worked in aerospace at what I consider a very high level and have seen it first hand.

The examples where I stated the F-35 could have been done at 10% of the cost is not only true but probably conservative. As you said in the other post:

Ozair wrote:
10% of the development cost... Sorry mate that is bonkers.


RJMAZ, my point still stands and the irony of your statement is you invalidate it with your very next post…
RJMAZ wrote:
Consider the F-35 systems like a phone operating system with the pre-installed apps. All they need to do is install the 6th gen fighter app and the new avionics are complete. Nearly all the work has been.

Engines can also be modelled in digital and problems found. No doubt every part of the engine can be tested for air flow, heat and strength in a digital environment.

So although you claim this new work can be done at 10% your new work sits on the bedrock of the funding paid for by the F-35 program. As Bikerthai made quite clear earlier up the thread you don’t get the materials, systems etc for free. That still takes time and money and all the claims you have made on how to do this on the cheap rely on that money being spent previously by other programs.

RJMAZ wrote:
It was. The physical airframe is the now the easiest part by a very long way. It makes sense to just use two off the shelf F135 engines and the F-35 avionics. The whole 6th gen prototype could go from a blank piece of paper to first flight of a near production ready prototype in under 2 years. They will no doubt just scale up number of AESA radar modules. The production engine will no doubt be an improved F-35 engine that will eventually be fitted to the F-35 in later production blocks.

Here again you rely on the F135 being already built and in service to reduce the blank sheet of paper to prototypee to 2 years. The F-35 program spent US$12 billion on the F135 and while some of that was the unique work to facilitate STOVL the bulk is general development and test of everything to do with making modern fighter engines. To get to their current prototype stage with the AETPs the US has spent upwards of US$4 billion in dev money. You’ve done the same thing again on the radar, just scale up the TR modules on an existing system with all the software development already paid for and then away you go… If you want to isolate all those costs away and just claim the airframe development is less that makes more sense but this only works today for the T-7, the B-21 and this potential new airframe if you ignore all the work done previously.

Note as well the NGAD program has already taken almost two billion dollars since 2016, not to mention any black funding which has contributed to this (currently 30% of USAF acquisition). That money has all gone to get this prototype (and maybe others) to this point. The forward projections for NGAD call for US$7.5 billion to FY25 and I think we can agree, even just based on the far simpler T-7 and its timings, that we won’t see NGAD enter USAF service in 2025.

The other interesting side of this is what the risk appetite will be from the US for testing of these aircraft. I expect the number of test and front line pilots that died due to insufficiently mature systems during the original century series is significant. The F-35 SDD program was incredibly risk averse and the rapid progression that is envisioned by Roper and others may only come at the expense of some test pilots and an acknowledgement that test regimes may not be as thorough as the previous generation.
 
Planeflyer
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 2:26 am

Good points on the risk to test pilots. I have been thinking about how SpaceX has progressed so much more quickly w their test to fail mantra. Could development ac be set up to be tested in a UAV mode so as to avoid pilot risk?
 
RJMAZ
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 2:44 am

Ozair wrote:
So although you claim this new work can be done at 10% your new work sits on the bedrock of the funding paid for by the F-35 program.

No I claimed the F-35 could have been done at 10% of the cost from the ground up using the current design tech

This 6th gen production ready prototype was probably built at a low single digit percentage of the first production block F-35. So low that the entire development could be hidden inside other budget and it probably did not even need to go to tender.


Ozair wrote:
As Bikerthai made quite clear earlier up the thread you don’t get the materials, systems etc for free.
The materials and systems are all faster. It can all be modelled. Maybe CMC technology for example is slow to go from the lab to the real world but the testing and use of the new technology is much faster.
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 3:35 am

RJMAZ wrote:
The materials and systems are all faster. It can all be modelled. Maybe CMC technology for example is slow to go from the lab to the real world but the testing and use of the new technology is much faster.


Easy for us to say. I recall that the material system for the F-32 ( and by inference the F-35) was a bi*** to manufacture. Shortly after that there was a big hoopla on themoplastic composite. That was over 15 years ago and I still have not seen anything that is near production ready.

Maybe they got it to work for this new airplane, it sure have not made it's way into commercial aviation.

And developing the material is only part of the cost. For any new material, an allowables program to quantify the strength will run in to millions and require time to execute before the engineers are confident enough to get it on the airplane. Digital modeling can help you analize the structure faster, but the material characterization to provide the basic values to be input into the models still takes time.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
LightningZ71
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 12:37 pm

Well, for the test pilot issue, please keep in mind that the NGAD is supposed to be optionally manned. They could choose to do initial flight testing with unmanned systems in control...
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 1:18 pm

LightningZ71 wrote:
Well, for the test pilot issue, please keep in mind that the NGAD is supposed to be optionally manned. They could choose to do initial flight testing with unmanned systems in control...


Now this is fresh concept. Once the AI is matured with the wingman drone, test pilots for the initial test phase may be obsolete.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
LightningZ71
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Re: USAF PCA and other 6th gen fighters

Thu Sep 17, 2020 8:04 pm

Assuming that they might want to stress the airframe for 12+G loads, a water filled meat sack in the cockpit is not just obsolete, but also not viable.

You can use a W&B and aerodynamically representative flight demonstrator to perfect the AI flight control system before the production quality prototype is done so that it can conduct a first flight without a pilot to prove that its normal operating envelope is safe.
 
Planeflyer
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 11:49 am

How likely is it that the first flights have been carried out without a pilot?
 
RJMAZ
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 12:32 pm

There will definitely be a pilot for the test flight. There is a 99% chance it has a F-35 cockpit which does not have unmanned capability yet.

The chance of an aircraft crashing due to a problem with the aerodynamics or the flight control software is zero.
 
texl1649
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 2:45 pm

Ozair wrote:
Well this is quite the surprise. Apparently the USAF have already built and flown a prototype of the NGAD, with the likelihood there may be additional prototypes from other manufacturers soon to fly as well. No further info on size, range, engine etc but certainly surprising. If this really is what the Digitial Century series will foster then look out every single other fighter program including F-35. There won't be a future for Tempest or FCAS outside their principal nations, and perhaps even none within, if the US can do this type of development so quickly.

The US Air Force has built and flown a mysterious full-scale prototype of its future fighter jet


The U.S. Air Force has secretly designed, built and flown at least one prototype of its enigmatic next-generation fighter jet, the service’s top acquisition official confirmed to Defense News on Sept. 14.

The development is certain to shock the defense community, which last saw the first flight of an experimental fighter during the battle for the Joint Strike Fighter contract 20 years ago. With the Air Force’s future fighter program still in its infancy, the rollout and successful first flight of a demonstrator was not expected for years.

“We’ve already built and flown a full-scale flight demonstrator in the real world, and we broke records in doing it,” Will Roper told Defense News in an exclusive interview ahead of the Air Force Association’s Air, Space and Cyber Conference. “We are ready to go and build the next-generation aircraft in a way that has never happened before.”

...

https://www.defensenews.com/breaking-ne ... ghter-jet/


I dunno, even accepting arguendo that this represents such a leap change in rapid prototyping/development, it will have to rely on a lot of systems/components built for the F-35 program, and with many of those it's not going to be quick/easy to export to all of the countries that, for instance, have purchased F-16's over the past 40 years. Some of that bravado even reminds me of how Boeing rolled out the first prototype 787; sure, not a perfect analogy but certainly not an indicator of EIS in the next 5 years.

And if it's not Boeing, it's gotta be NG or LM; neither of them have any track record of delivering rapidly new affordable combat aircraft like this. The B-21 and various LM helicopter/vertical lift programs are a demonstration of their present capabilities.
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 2:55 pm

This reminded me of the time when the B-2 went public.
:fluffy:
bt
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Planeflyer
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 6:30 pm

texl1649 wrote:
Ozair wrote:
Well this is quite the surprise. Apparently the USAF have already built and flown a prototype of the NGAD, with the likelihood there may be additional prototypes from other manufacturers soon to fly as well. No further info on size, range, engine etc but certainly surprising. If this really is what the Digitial Century series will foster then look out every single other fighter program including F-35. There won't be a future for Tempest or FCAS outside their principal nations, and perhaps even none within, if the US can do this type of development so quickly.

The US Air Force has built and flown a mysterious full-scale prototype of its future fighter jet


The U.S. Air Force has secretly designed, built and flown at least one prototype of its enigmatic next-generation fighter jet, the service’s top acquisition official confirmed to Defense News on Sept. 14.

The development is certain to shock the defense community, which last saw the first flight of an experimental fighter during the battle for the Joint Strike Fighter contract 20 years ago. With the Air Force’s future fighter program still in its infancy, the rollout and successful first flight of a demonstrator was not expected for years.

“We’ve already built and flown a full-scale flight demonstrator in the real world, and we broke records in doing it,” Will Roper told Defense News in an exclusive interview ahead of the Air Force Association’s Air, Space and Cyber Conference. “We are ready to go and build the next-generation aircraft in a way that has never happened before.”

...

https://www.defensenews.com/breaking-ne ... ghter-jet/


I dunno, even accepting arguendo that this represents such a leap change in rapid prototyping/development, it will have to rely on a lot of systems/components built for the F-35 program, and with many of those it's not going to be quick/easy to export to all of the countries that, for instance, have purchased F-16's over the past 40 years. Some of that bravado even reminds me of how Boeing rolled out the first prototype 787; sure, not a perfect analogy but certainly not an indicator of EIS in the next 5 years.

And if it's not Boeing, it's gotta be NG or LM; neither of them have any track record of delivering rapidly new affordable combat aircraft like this. The B-21 and various LM helicopter/vertical lift programs are a demonstration of their present capabilities.


Well, assuming it flew, this in itself is a good indication that the time to develop has certainly been significantly compressed.
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 7:33 pm

Planeflyer wrote:
Well, assuming it flew, this in itself is a good indication that the time to develop has certainly been significantly compressed.


You can only assume this if you also assume that they started this project recently. Could have been on the drawing block for a while. Or could gave waited for a break through tech. My guess is that they have been working the design for quite some time, but did not find someone who can build their frame quickly and cost effectively until recently.

If I was venture to guess, the design would either be USAF or Skunkworks and the actual fabricator would be Boeing, unless LM has developed their own digital manufacturing process.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
Planeflyer
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 8:55 pm

Yep, I'm assuming the project was started recently as in the past few years. Let's hope they can do better on the timeline that was achieved on the F35.
 
Ozair
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Re: USAF PCA and other 6th gen fighters

Fri Sep 18, 2020 9:50 pm

texl1649 wrote:

I dunno, even accepting arguendo that this represents such a leap change in rapid prototyping/development, it will have to rely on a lot of systems/components built for the F-35 program, and with many of those it's not going to be quick/easy to export to all of the countries that, for instance, have purchased F-16's over the past 40 years.

My point exactly although the F-35 was always built to export. Saying that, I don't expect the first few interations of the DCS to be export aircraft. The USAF is envisioning short high volume production runs, 50-80 aircraft a year very similar to how the F-15A/C was built rapidly over a short period.

texl1649 wrote:
And if it's not Boeing, it's gotta be NG or LM; neither of them have any track record of delivering rapidly new affordable combat aircraft like this. The B-21 and various LM helicopter/vertical lift programs are a demonstration of their present capabilities.

The DSC intent is to have design houses essentially separate from the manufacturing base, with the IP being completely retained by the USAF. I agree this first one is likely one of the three primes but hopefully Kratos and General Atomics and Esper even suggested an Elon Musk owned company enter the fray for design and additional other manufacturers want to take on the build work, such as Spirit, as well as the traditional base.

bikerthai wrote:
Planeflyer wrote:
Well, assuming it flew, this in itself is a good indication that the time to develop has certainly been significantly compressed.


You can only assume this if you also assume that they started this project recently. Could have been on the drawing block for a while. Or could gave waited for a break through tech. My guess is that they have been working the design for quite some time, but did not find someone who can build their frame quickly and cost effectively until recently.

If I was venture to guess, the design would either be USAF or Skunkworks and the actual fabricator would be Boeing, unless LM has developed their own digital manufacturing process.

bt

I think the records Esper spoke about in revealing this is the time to flight and rapid build etc and not related to the aircraft performance so it probably has been a reasonably rapid design to first flight.

LightningZ71 wrote:
Assuming that they might want to stress the airframe for 12+G loads, a water filled meat sack in the cockpit is not just obsolete, but also not viable.

You can use a W&B and aerodynamically representative flight demonstrator to perfect the AI flight control system before the production quality prototype is done so that it can conduct a first flight without a pilot to prove that its normal operating envelope is safe.

DARPA in their AI trials are talking about a combined pilot and AI flown aircraft using the strengths of each. I expect that the DCS intent is manned aircraft and the unmanned component will be the loyal wingman and MQ-Next aircraft.

But either way, at some point a test pilot is going to get in the aircraft and may need to push it outside the envelope. In the same way an operational pilot is at some point going to get in the aircraft and potentially push it in ways the test program or software didn't predict. With the F-35 being the most tested flight program in history how thorough will the USAF be with the DCS and what timeframe delay are they willing to accept...
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Sat Sep 19, 2020 3:04 am

Ozair wrote:
The DSC intent is to have design houses essentially separate from the manufacturing base, with the IP being completely retained by the USAF.


Well, there's IP and there's knowhow. You can develop your IP, but if you don't retain the designers, all that IP does you no good. When they talk about internal design house, I wonder of it's government paid employee, or temporary sub contract. Either way, it does not bode well in the long run as far as my experience tells me.

bt
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Ozair
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Re: USAF PCA and other 6th gen fighters

Tue Sep 22, 2020 12:47 am

bikerthai wrote:
Ozair wrote:
The DSC intent is to have design houses essentially separate from the manufacturing base, with the IP being completely retained by the USAF.


Well, there's IP and there's knowhow. You can develop your IP, but if you don't retain the designers, all that IP does you no good. When they talk about internal design house, I wonder of it's government paid employee, or temporary sub contract. Either way, it does not bode well in the long run as far as my experience tells me.

bt

The intent is that the design houses only design and continue to move from one design to the next while the manufacturers only manufacturer. The platforms emerging out of the DCS are only expected to operate for 10 to 15 years before they are replaced. Perhaps this is an intent by the USAF to move away from big primes but they are keen to separate out those two layers.

Further to the conversation is the following Check 6 podcast which covered the NGAD announcements. https://aviationweek.com/shows-events/a ... ration-air

Steve Trimble basically admits he missed the hints given to him over the last couple of years and now has pieced some of it together on how long, the progression and where the USAF is going with NGAD as well as AETP etc. Interesting as well when you place these prototypes against the Mosaic Warfare Concept that also seems to be the flavour of the month for USAF planners.
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Tue Sep 22, 2020 4:03 am

Ozair wrote:
Perhaps this is an intent by the USAF to move away from big primes


Which means they have to become the prime themselves. A very dificult prospect for a government entity. We'll see how far they can go with this approach.

bt
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Ozair
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Re: USAF PCA and other 6th gen fighters

Wed Sep 23, 2020 9:00 am

bikerthai wrote:
Ozair wrote:
Perhaps this is an intent by the USAF to move away from big primes


Which means they have to become the prime themselves. A very dificult prospect for a government entity. We'll see how far they can go with this approach.

bt


The following is an assessment and overview of how the DCS process may flow. While I don't expect a single prime will go from design to production there is no reason they couldn't but I expect most will find value in focusing on one leg of the chain or completely separating out the design and production businesses from each other (and may be forced to do this...). The US Military has a significant number of initiatives trying to grow the industrial base, which has been shrinking rapidly, and DCS seems ready made for small design or manufacturing to come in and gain a foothold in a space that was previously the bastion of the large and politically connected.

The Air Force Digital Century Series: Beyond the Buzzwords

the USAF intends for the Digital Century Series’ acquisition strategy to fundamentally shift industrial base incentives away from sustaining old systems and toward developing and delivering new ones

https://www.csis.org/analysis/air-force ... -buzzwords

As above states though at the moment with the current big programs, and examples of most pertinently Boeing's recent bids, there will be less incentive to underbid on design and production with the absence of the long 50 year sustainment tails to pump up the business. The majority of these DCS aircraft are planned to operate for 5-10 years before they are replaced. I still see some serious long term training issues with that type of plan but perhaps AI advancements will remove the day to day business of flying the aircraft and transition the pilot to a battlespace manager, in a similar way the F-35 has transformed their aircrew from 4th gen to a 5th gen mindset and situational awareness.
 
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bikerthai
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Re: USAF PCA and other 6th gen fighters

Wed Sep 23, 2020 12:23 pm

Having listened to the podcast, have a better sense what they are talking about. Seems to me they are thinking in the line of a distributed network where if you run in to trouble with one tech, you are not hamstringing the development of another.

Low production rates with rapidly changing tech. Hope they have a plan for he support side of the equation. Or I guess they can contract that out in small batches as well.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.

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