Lockheed to pitch hybrid "F-22/F-35" design for export to Japan

LightningZ71 · Tue Jul 10, 2018 2:38 pm

LOL, you have that right. That the SuperHornet was sold as a simple upgrade to the legacy hornet was political maneuvering at it's finest. Granted, the SuperHornet is a fine aircraft for it's purpose, it may not have been ideal to meet the Navy's needs at the time as compared to what could have been done by competitors.

The F-16XL was a solid advancement for the F-16. With a bit more development, it would have made for an interesting product for a lot of buyers. However, it wasn't miles better than the competition at the time. It needed a bit more power and perhaps some more attention to low observability. I suspect that, if development had continued a few more years, and it could have gotten an upgraded/uprated engine, the CFTs that were developed for the F-16 and the diverterless supersonic duct that was prototyped on another F-16 frame, it would have been a much more attractive product on the export market as it would have solved it's range problems, it's performance deficits as compared the the Strike Eagle it was originally bid against, and would have likely had a lower RCS than many competing platforms due at least partially to having a smaller size. I really wish that that had seen the light of day.

Getting back on topic, While I don't see NG pitching a revived F-23, I do think that that particular overall design had some attractive qualities. It wouldn't shock me to see a further development of the concept into a newer product that "resembles" it.

As for the endurance qualities of the F-35, remember that it carries most of it's stores internally. Load an F-2 with a pair of ASMs and then an F-35 with a pair of ASMs (
which should fit internally for two) and then compare their flight ranges. Then compare how close they can get to the enemy without being detected. Then, give the F-2 its external tanks that it almost always carries and do the same exercise. The F-35 will be able to get closer and launch, then retreat over and over again without coming under threat, unlike the F-2, which will need the external tanks for better range, but will become even more observable in the process. Then, if you absolutely have to carry 4 ASMs in a heavy assault profile, the F-35 can still do that, and also carry external tanks to get the same range. It's about flexibility.

estorilm · Wed Jul 11, 2018 4:12 pm

This order will likely not be large enough to justify a clean-sheet design (or really any program) from NG, IMHO. Plus one might need to consider recent trade concerns as well.

The YF-23 argument seems pointless to me - it's fun to think about, but in addition to losing out over two decades ago, it would need to not only catch up with developments in the past two decades which which the Raptor has been benefiting from (as well as an incredible amount of funding for Lockheed to do so) but surpass where the F-22 stands in its latest iteration. Then you have the systems and experience obtained with the F-35 project as well, you've got to catch up and surpass the achievements and capabilities of that current program as well. THEN with all of that figured out, build a new plane which is cheaper and employs the same (or better) technology at a faster intro to service than Lockheed? It just blows my mind to even comprehend such a feat. There's no way. PLUS presumably you'd only be selling a few aircraft anyways, at least the only firm commitment would be from Japan.

Like it or not, Lockheed would seem to have a massive advantage of building such an aircraft, and the company as a whole is set up fighter design, from prior R&D to engineering staff, computer modeling, etc. Besides I think Northrop is busy trying to stay on time and on budget for the B-21.

Perhaps they could use the F-35C as a starting point, with the larger wing and 20,000 internal fuel capacity - remove the folding wing mechanism and get some more fuel in there. They could perhaps "fatten" the fuselage a bit to fit more in the weapons bays, or make them deeper at the expense of some internal fuel capacity, but I still think that Japan's goal of internal weapons seems unattainable with a single-engine design.

Ozair · Thu Jul 12, 2018 2:09 am

estorilm wrote:

The YF-23 argument seems pointless to me - it's fun to think about, but in addition to losing out over two decades ago, it would need to not only catch up with developments in the past two decades which which the Raptor has been benefiting from (as well as an incredible amount of funding for Lockheed to do so) but surpass where the F-22 stands in its latest iteration. Then you have the systems and experience obtained with the F-35 project as well, you've got to catch up and surpass the achievements and capabilities of that current program as well. THEN with all of that figured out, build a new plane which is cheaper and employs the same (or better) technology at a faster intro to service than Lockheed? It just blows my mind to even comprehend such a feat.

Agree completely. Technology has moved on significantly from the YF-23, especially when you consider that the selection was made in 1991… nearly 21 years ago.

estorilm wrote:

Perhaps they could use the F-35C as a starting point, with the larger wing and 20,000 internal fuel capacity - remove the folding wing mechanism and get some more fuel in there. They could perhaps "fatten" the fuselage a bit to fit more in the weapons bays, or make them deeper at the expense of some internal fuel capacity, but I still think that Japan's goal of internal weapons seems unattainable with a single-engine design.

The C would be a bad choice to base the Japanese aircraft on given the wing significantly impacts transonic acceleration. They are after essentially a platform capable of supercruise and the F-35C will never be an effective supercruiser. It also doesn’t have a range advantage over the A model even though it carries more fuel. Sure you could take out some weight from the wing and perhaps fuselage with the requirement to not take off and land on a carrier but it would be better to just use the A model and pay $40 million less per copy.

The overall best option is to wait for the Adaptive engine upgrade that is coming for the F-35 fleet and follow on US fighter in the mid 2020s. That promises 30% range increase at higher thrusts and should push the combat radius of the F-35A easily past 1000nm and likely in the profiles the Japanese would fly greater than 1200nm radius.

Tugger · Thu Jul 12, 2018 4:28 am

Ozair wrote:
Agree completely. Technology has moved on significantly from the YF-23, especially when you consider that the selection was made in 1991… nearly 21 years ago.

Hmmm.... I think you mean 27 years ago? Or nearly 30 years ago....? :scratchchin:

Tugg

Ozair · Thu Jul 12, 2018 6:25 am

Tugger wrote:
Ozair wrote:
Agree completely. Technology has moved on significantly from the YF-23, especially when you consider that the selection was made in 1991… nearly 21 years ago.

Hmmm.... I think you mean 27 years ago? Or nearly 30 years ago....?

Tugg

It is 2012 isn't it...

Ozair · Mon Jul 16, 2018 12:04 am

An update on what Japan are considering for their F-2 replacement. Frustrating that we don’t know any more details about what LM, or the other manufacturers have proposed. there is some price info which states LM is suggesting approx US$180 milion per aircraft...

Lockheed Martin seen leading race to develop F-2’s successor

The Defense Ministry views Lockheed Martin Corp. as the leading candidate to develop fighter jets to succeed the F-2 fighters in the Air Self-Defense Force, according to government sources.

Lockheed, fellow major American defense contractor Boeing Co. and Britain’s BAE Systems PLC submitted their proposals on developing a successor to the F-2 to the ministry on Friday.

Though the ministry favors Lockheed’s plan, it is carefully examining the three proposals as the price presented by Lockheed was higher than the initial estimate.

According to the government sources, Lockheed’s plan is to develop the new fighters based on the F-22, which are the U.S. Air Force’s high-performing stealth fighters. The proposal calls for the installment of electronic devices that are used in F-35 fighter jets, which are part of the ASDF fleet, in the new fighters. The plan assumes that Japan and the United States will jointly develop the new aircraft.

Boeing’s plan is to use F-15 fighters, which are the ASDF’s mainstay fighters, as the basis of the new fighters, which will have partial stealth capabilities through joint Japan-U.S. development.

BAE Systems’ plan will have Japan and Britain jointly developing the new fighters by utilizing technologies applied to Typhoon fighters, which are the British Royal Air Force’s mainstay fighter jets.
The ASDF now possesses about 90 F-2 fighters. These will start to be retired from service beginning around 2030.

In February, the ministry notified the three companies of the capability requirements for the successor fighter model. Among the demands was that the new fighters be high-performance stealth jets with a maximum speed above Mach 2. The ministry requested the three companies to provide their proposals by Friday.

According to the government sources, Lockheed’s plan better meets the demands of the ministry, mainly in terms of stealth capabilities compared with the plans of the other two companies, as the proposed development of the new fighters will be based on the F-22. The F-22 has been dubbed the “world’s most powerful” fighter jet, praised for its high-level stealth capabilities that make it extremely hard to detect by radar and its flight performance.

In Lockheed’s plan, however, the proposed price for each new fighters is more than ¥20 billion, which is far higher than the ministry’s initial estimate.

If development and production costs are so high, it is possible that the ministry may reject the company’s plan from the standpoint of cost-effectiveness.

Another focus of attention will be the extent to which Japanese companies will be involved in the development.

In the past, the government tried to import F-22 fighters, but the United States prohibited exports of the F-22 to prevent U.S. military technologies from being stolen. Japan thus decided to introduce F-35 fighters instead.

The current administration of U.S. President Donald Trump is enthusiastic in expanding exports of U.S. weapons. Thus, it is possible that the U.S. administration will allow the plan to develop Japan’s new fighters based on the F-22.

The ministry has also compiled an initiative as part of the design of the new fighters that the successors to the F-2 will carry small, unmanned aircraft for detecting enemies in faraway positions. But the ministry sees this option as a medium- to long-term issue, so it was not included in the demands for the new fighter capabilities

http://www.the-japan-news.com/news/article/0004585084

estorilm · Mon Jul 16, 2018 12:57 pm

Ozair wrote:
estorilm wrote:

The C would be a bad choice to base the Japanese aircraft on given the wing significantly impacts transonic acceleration. They are after essentially a platform capable of supercruise and the F-35C will never be an effective supercruiser. It also doesn’t have a range advantage over the A model even though it carries more fuel. Sure you could take out some weight from the wing and perhaps fuselage with the requirement to not take off and land on a carrier but it would be better to just use the A model and pay $40 million less per copy.

The overall best option is to wait for the Adaptive engine upgrade that is coming for the F-35 fleet and follow on US fighter in the mid 2020s. That promises 30% range increase at higher thrusts and should push the combat radius of the F-35A easily past 1000nm and likely in the profiles the Japanese would fly greater than 1200nm radius.

Good point - I hadn't even really thought about the supercruise limitations - in addition to the fuel I suppose the primary requirement was manageable TO/landing speeds for carrier use.

In any event, while the next gen engine upgrades will indeed be impressive for the F-35 program, I'm still not sure it'll be capable of supercruise (even with a sleek design and two VERY powerful engines, the F-22 engineers had a difficult time achieving it - even late into the design phase they were modifying large elements in the wind tunnel.)

The biggest thing is Japan's strange requirement for 8 (I believe?) internally-stored air-to-air missiles. I don't really see any iteration of the F-35 being capable of this.

estorilm · Mon Jul 16, 2018 1:10 pm

Ozair wrote:
An update on what Japan are considering for their F-2 replacement. Frustrating that we don’t know any more details about what LM, or the other manufacturers have proposed. there is some price info which states LM is suggesting approx US$180 milion per aircraft...

Lockheed Martin seen leading race to develop F-2’s successor

The Defense Ministry views Lockheed Martin Corp. as the leading candidate to develop fighter jets to succeed the F-2 fighters in the Air Self-Defense Force, according to government sources.

Lockheed, fellow major American defense contractor Boeing Co. and Britain’s BAE Systems PLC submitted their proposals on developing a successor to the F-2 to the ministry on Friday.

Though the ministry favors Lockheed’s plan, it is carefully examining the three proposals as the price presented by Lockheed was higher than the initial estimate.

According to the government sources, Lockheed’s plan is to develop the new fighters based on the F-22, which are the U.S. Air Force’s high-performing stealth fighters. The proposal calls for the installment of electronic devices that are used in F-35 fighter jets, which are part of the ASDF fleet, in the new fighters. The plan assumes that Japan and the United States will jointly develop the new aircraft.

Boeing’s plan is to use F-15 fighters, which are the ASDF’s mainstay fighters, as the basis of the new fighters, which will have partial stealth capabilities through joint Japan-U.S. development.

BAE Systems’ plan will have Japan and Britain jointly developing the new fighters by utilizing technologies applied to Typhoon fighters, which are the British Royal Air Force’s mainstay fighter jets.
The ASDF now possesses about 90 F-2 fighters. These will start to be retired from service beginning around 2030.

In February, the ministry notified the three companies of the capability requirements for the successor fighter model. Among the demands was that the new fighters be high-performance stealth jets with a maximum speed above Mach 2. The ministry requested the three companies to provide their proposals by Friday.

According to the government sources, Lockheed’s plan better meets the demands of the ministry, mainly in terms of stealth capabilities compared with the plans of the other two companies, as the proposed development of the new fighters will be based on the F-22. The F-22 has been dubbed the “world’s most powerful” fighter jet, praised for its high-level stealth capabilities that make it extremely hard to detect by radar and its flight performance.

In Lockheed’s plan, however, the proposed price for each new fighters is more than ¥20 billion, which is far higher than the ministry’s initial estimate.

If development and production costs are so high, it is possible that the ministry may reject the company’s plan from the standpoint of cost-effectiveness.

Another focus of attention will be the extent to which Japanese companies will be involved in the development.

In the past, the government tried to import F-22 fighters, but the United States prohibited exports of the F-22 to prevent U.S. military technologies from being stolen. Japan thus decided to introduce F-35 fighters instead.

The current administration of U.S. President Donald Trump is enthusiastic in expanding exports of U.S. weapons. Thus, it is possible that the U.S. administration will allow the plan to develop Japan’s new fighters based on the F-22.

The ministry has also compiled an initiative as part of the design of the new fighters that the successors to the F-2 will carry small, unmanned aircraft for detecting enemies in faraway positions. But the ministry sees this option as a medium- to long-term issue, so it was not included in the demands for the new fighter capabilities

http://www.the-japan-news.com/news/article/0004585084

Very interesting, and surprisingly close to what I conjured up earlier in the thread.

The advantages LM has makes Boeing's F-15-based proposal almost embarrassing. The entire point of this process highlighted the needs of something better than their domestic stealth attempts as well as their latest F-15 variants.

As far as the price being higher than they wanted... uhm. They're asking for essentially a tailor-made aircraft which will most likely become the most powerful and deadly in the world. Something that (in their time frame and budget) only one country and one company is capable of creating. Not exactly the best position to be in if you plan on negotiating! :white:

In any event, compared to a Typhoon or F-15 variant, the LM proposal would almost certainly jump out into a totally different realm of capabilities. Based on their initial request for proposals, it would seem they're seeking something exclusive that no current design can achieve now - BAE and Boeing will have a tough time here. At the end of the day, they already have VERY capable F-35's coming on-line, they want something beyond that aircraft, and I'm not sure anyone would want to be driving an F-15 or Typhoon against an F-35.

Even an advanced variation of either aircraft would seem sub-par to their existing F-35 fleet.

LightningZ71 · Mon Jul 16, 2018 4:28 pm

I'm guessing that Boeing is again pitching a development of their "Silent Eagle" project? While it would be a marked improvement over the F-2 in most every way, it won't be inexpensive to procure (just look at the latest SA and QR variants and how much they cost without expensive work being done for RCS), and it certainly won't be extremely stealthy. A merging of the F-22 with the F-35 systems, with the incorporation of lessons learned over the years from operation and upkeep, will certainly be a leader from a capability standpoint. The Typhoon project will have such a long lead time, I can't imagine that it would be ready in the timeframe that they want.

estorilm · Tue Jul 17, 2018 4:02 pm

LightningZ71 wrote:
I'm guessing that Boeing is again pitching a development of their "Silent Eagle" project? While it would be a marked improvement over the F-2 in most every way, it won't be inexpensive to procure (just look at the latest SA and QR variants and how much they cost without expensive work being done for RCS), and it certainly won't be extremely stealthy. A merging of the F-22 with the F-35 systems, with the incorporation of lessons learned over the years from operation and upkeep, will certainly be a leader from a capability standpoint. The Typhoon project will have such a long lead time, I can't imagine that it would be ready in the timeframe that they want.

There are some aspects of the Silent Eagle that are interesting - presumably enough to warrant the proposal, but there are also glaring deficiencies.

As an air superiority "interceptor" type, it would be great - as it's extremely fast (at least compared to F-35) and can carry a LOT of A2A weapons. It also has powerful electronics, radar, etc..

My issue is really seeing this thing confronting the perceived threat for Japan, which would be 5th gen aircraft from China, advanced UCAVs, etc - and I'm just not sure you'd want a 4+ gen fighter going up against those machines. The other issue is cost - I continue to be amazed at the price the latest F-15 variants command, when you're dumping that kind of cash into a program, it's just painfully tempting to go that extra bit further and obtain what would be possibly the best fighter in the world in LM's proposal.

Ozair · Tue Jul 17, 2018 10:36 pm

Cost is clearly going to be an issue for this and restarting F-22 production was always going to cost a lot of money and that is before the airframe is upgraded with F-35 tech. If I was a gambler I would put my money on the end result being more locally manufactured F-35s to replace the F-2s. Joining the new UK program is certainly a possibility but it doesn’t fit the replacement timeframe Japan is looking at.

High cost may disrupt plans for new fighter jet

The Defense Ministry’s plan to jointly develop a successor to the Air Self-Defense Force’s F-2 fighter jet has been shaken, as the price presented by Lockheed Martin Corp. was far higher than the initial estimate.

The ministry has been exploring the possibility of jointly developing the successor model with other countries, with Japan taking the lead. Yet questions have been raised over the cost-effectiveness of this approach, in which the proposal from Lockheed had been favored.

Currently, the ASDF deploys about 90 F-2 fighters, which are expected to be retired from service from around 2030.

Given that it takes about 10 years to develop a fighter jet, the ministry hopes to include its concrete plan to develop the fighters in the next Medium Term Defense Program for fiscal 2019 to fiscal 2023, which will be compiled at the end of this year.

The ministry has studied three options, including Lockheed’s plan to develop a new high-performance stealth jet based on the F-22 (see below) and equipped with electronic devices from the F-35.

The other two options have been presented by Boeing Co. and Britain’s BAE Systems PLC. Boeing has proposed applying technologies from F-15 fighters — the ASDF’s mainstay fighters — while BAE Systems proposed the use of technologies of Typhoon fighters, which are the mainstay of the British Royal Air Force.

These three proposals have been made on the premise of joint development with Japan.

Lockheed’s proposal exceeds the other two in terms of stealth capabilities and flight performance. Since the information-gathering stage, therefore, the ministry has viewed it as the leading candidate to develop the successor to the F-2.

Lockheed, however, submitted its official proposal Friday with a price tag of more than ¥20 billion for the new fighter. This is far higher than the ministry’s initial estimate of ¥15 billion, and far above the ¥13.1 billion price tag for the F-35 introduced by the ASDF.

“It’s just too expensive. We can’t accept this in its current form,” a senior ministry official said.

There are three options for the development of the successor to the F-2: domestic development, joint development with another country, and improvement of existing, foreign-made planes.

The Defense Ministry and Liberal Democratic Party members with strong ties to the ministry and the defense industry support the domestic development of the jets, so as to maintain the domestic defense-related industry’s production and technology bases.

However, enormous budget spending would be required to do this. The cost of developing a new fighter jet domestically is estimated at about ¥1 trillion to ¥2 trillion. The entire project, including production and maintenance, is estimated to reach ¥6 trillion.

The Finance Ministry, which plays a key role in budget compilation, is negative about the development of new fighter jets regardless of whether they are developed solely by Japan or jointly with another nation. Its position is prompted by concerns about cost-effectiveness and the uncertainty linked to newly developed planes.

“The government just should purchase extra F-35 fighter jets,” a Finance Ministry source said.

To address the Finance Ministry’s concerns, the Defense Ministry has explored the basic idea of joint development that would apply the technologies of Japanese firms to U.S. fighters with a strong performance record.

Even if the major hurdle of cost is cleared, problems remain with Lockheed’s proposal.

As U.S. technologies are applied to key components such as fuselage, engine and electronic devices, joint development would likely be led by the United States. If Japan is not involved in the core parts of the development, repair and maintenance of the new jets would not be conducted domestically.

About 10 countries including Japan, the United States, Britain and Russia currently have technologies to develop fighter jets. Of these, only the United States, China and Russia are said to be able to develop stealth fighters.

“If Japan cannot develop F-2 successors led by domestic companies, we’ll miss an opportunity to advance our technologies,” a senior Defense Ministry official said. “And we could lose our position as a developer of fighter jets.

http://the-japan-news.com/news/article/0004590698

ThePointblank · Wed Jul 18, 2018 4:29 am

Ozair wrote:
Cost is clearly going to be an issue for this and restarting F-22 production was always going to cost a lot of money and that is before the airframe is upgraded with F-35 tech. If I was a gambler I would put my money on the end result being more locally manufactured F-35s to replace the F-2s. Joining the new UK program is certainly a possibility but it doesn’t fit the replacement timeframe Japan is looking at.

High cost may disrupt plans for new fighter jet

The Defense Ministry’s plan to jointly develop a successor to the Air Self-Defense Force’s F-2 fighter jet has been shaken, as the price presented by Lockheed Martin Corp. was far higher than the initial estimate.

The ministry has been exploring the possibility of jointly developing the successor model with other countries, with Japan taking the lead. Yet questions have been raised over the cost-effectiveness of this approach, in which the proposal from Lockheed had been favored.

Currently, the ASDF deploys about 90 F-2 fighters, which are expected to be retired from service from around 2030.

Given that it takes about 10 years to develop a fighter jet, the ministry hopes to include its concrete plan to develop the fighters in the next Medium Term Defense Program for fiscal 2019 to fiscal 2023, which will be compiled at the end of this year.

The ministry has studied three options, including Lockheed’s plan to develop a new high-performance stealth jet based on the F-22 (see below) and equipped with electronic devices from the F-35.

The other two options have been presented by Boeing Co. and Britain’s BAE Systems PLC. Boeing has proposed applying technologies from F-15 fighters — the ASDF’s mainstay fighters — while BAE Systems proposed the use of technologies of Typhoon fighters, which are the mainstay of the British Royal Air Force.

These three proposals have been made on the premise of joint development with Japan.

Lockheed’s proposal exceeds the other two in terms of stealth capabilities and flight performance. Since the information-gathering stage, therefore, the ministry has viewed it as the leading candidate to develop the successor to the F-2.

Lockheed, however, submitted its official proposal Friday with a price tag of more than ¥20 billion for the new fighter. This is far higher than the ministry’s initial estimate of ¥15 billion, and far above the ¥13.1 billion price tag for the F-35 introduced by the ASDF.

“It’s just too expensive. We can’t accept this in its current form,” a senior ministry official said.

There are three options for the development of the successor to the F-2: domestic development, joint development with another country, and improvement of existing, foreign-made planes.

The Defense Ministry and Liberal Democratic Party members with strong ties to the ministry and the defense industry support the domestic development of the jets, so as to maintain the domestic defense-related industry’s production and technology bases.

However, enormous budget spending would be required to do this. The cost of developing a new fighter jet domestically is estimated at about ¥1 trillion to ¥2 trillion. The entire project, including production and maintenance, is estimated to reach ¥6 trillion.

The Finance Ministry, which plays a key role in budget compilation, is negative about the development of new fighter jets regardless of whether they are developed solely by Japan or jointly with another nation. Its position is prompted by concerns about cost-effectiveness and the uncertainty linked to newly developed planes.

“The government just should purchase extra F-35 fighter jets,” a Finance Ministry source said.

To address the Finance Ministry’s concerns, the Defense Ministry has explored the basic idea of joint development that would apply the technologies of Japanese firms to U.S. fighters with a strong performance record.

Even if the major hurdle of cost is cleared, problems remain with Lockheed’s proposal.

As U.S. technologies are applied to key components such as fuselage, engine and electronic devices, joint development would likely be led by the United States. If Japan is not involved in the core parts of the development, repair and maintenance of the new jets would not be conducted domestically.

About 10 countries including Japan, the United States, Britain and Russia currently have technologies to develop fighter jets. Of these, only the United States, China and Russia are said to be able to develop stealth fighters.

“If Japan cannot develop F-2 successors led by domestic companies, we’ll miss an opportunity to advance our technologies,” a senior Defense Ministry official said. “And we could lose our position as a developer of fighter jets.

http://the-japan-news.com/news/article/0004590698

Or, maybe develop a Japanese-specific variant of the F-35, fitted with interfaces for Japanese developed avionics and weapons, like the Israeli's.

estorilm · Wed Jul 18, 2018 3:13 pm

ThePointblank wrote:
Ozair wrote:
Cost is clearly going to be an issue for this and restarting F-22 production was always going to cost a lot of money and that is before the airframe is upgraded with F-35 tech. If I was a gambler I would put my money on the end result being more locally manufactured F-35s to replace the F-2s. Joining the new UK program is certainly a possibility but it doesn’t fit the replacement timeframe Japan is looking at.

High cost may disrupt plans for new fighter jet

The Defense Ministry’s plan to jointly develop a successor to the Air Self-Defense Force’s F-2 fighter jet has been shaken, as the price presented by Lockheed Martin Corp. was far higher than the initial estimate.

The ministry has been exploring the possibility of jointly developing the successor model with other countries, with Japan taking the lead. Yet questions have been raised over the cost-effectiveness of this approach, in which the proposal from Lockheed had been favored.

Currently, the ASDF deploys about 90 F-2 fighters, which are expected to be retired from service from around 2030.

Given that it takes about 10 years to develop a fighter jet, the ministry hopes to include its concrete plan to develop the fighters in the next Medium Term Defense Program for fiscal 2019 to fiscal 2023, which will be compiled at the end of this year.

The ministry has studied three options, including Lockheed’s plan to develop a new high-performance stealth jet based on the F-22 (see below) and equipped with electronic devices from the F-35.

The other two options have been presented by Boeing Co. and Britain’s BAE Systems PLC. Boeing has proposed applying technologies from F-15 fighters — the ASDF’s mainstay fighters — while BAE Systems proposed the use of technologies of Typhoon fighters, which are the mainstay of the British Royal Air Force.

These three proposals have been made on the premise of joint development with Japan.

Lockheed’s proposal exceeds the other two in terms of stealth capabilities and flight performance. Since the information-gathering stage, therefore, the ministry has viewed it as the leading candidate to develop the successor to the F-2.

Lockheed, however, submitted its official proposal Friday with a price tag of more than ¥20 billion for the new fighter. This is far higher than the ministry’s initial estimate of ¥15 billion, and far above the ¥13.1 billion price tag for the F-35 introduced by the ASDF.

“It’s just too expensive. We can’t accept this in its current form,” a senior ministry official said.

There are three options for the development of the successor to the F-2: domestic development, joint development with another country, and improvement of existing, foreign-made planes.

The Defense Ministry and Liberal Democratic Party members with strong ties to the ministry and the defense industry support the domestic development of the jets, so as to maintain the domestic defense-related industry’s production and technology bases.

However, enormous budget spending would be required to do this. The cost of developing a new fighter jet domestically is estimated at about ¥1 trillion to ¥2 trillion. The entire project, including production and maintenance, is estimated to reach ¥6 trillion.

The Finance Ministry, which plays a key role in budget compilation, is negative about the development of new fighter jets regardless of whether they are developed solely by Japan or jointly with another nation. Its position is prompted by concerns about cost-effectiveness and the uncertainty linked to newly developed planes.

“The government just should purchase extra F-35 fighter jets,” a Finance Ministry source said.

To address the Finance Ministry’s concerns, the Defense Ministry has explored the basic idea of joint development that would apply the technologies of Japanese firms to U.S. fighters with a strong performance record.

Even if the major hurdle of cost is cleared, problems remain with Lockheed’s proposal.

As U.S. technologies are applied to key components such as fuselage, engine and electronic devices, joint development would likely be led by the United States. If Japan is not involved in the core parts of the development, repair and maintenance of the new jets would not be conducted domestically.

About 10 countries including Japan, the United States, Britain and Russia currently have technologies to develop fighter jets. Of these, only the United States, China and Russia are said to be able to develop stealth fighters.

“If Japan cannot develop F-2 successors led by domestic companies, we’ll miss an opportunity to advance our technologies,” a senior Defense Ministry official said. “And we could lose our position as a developer of fighter jets.

http://the-japan-news.com/news/article/0004590698

Or, maybe develop a Japanese-specific variant of the F-35, fitted with interfaces for Japanese developed avionics and weapons, like the Israeli's.

That's not what their request was for though - the parameters and specs of the overall aircraft would remain the same, which they already know about and seem happy with (as a strike aircraft, and "good" A2A combat platform).

The initial article I read stated that they wanted higher speeds and up to 8 internally-carried A2A weapons, basically an air superiority / interceptor type aircraft to go up against anything China may throw at them. I believe they also wanted the capability to carry large anti-ship weapons, which isn't really possible in the F-35 with a decent A2A loadout simultaneously. Clearly a very different aircraft than the Lightning II - but we knew this, at they're already receiving F-35s and have subsequently sent out a proposal for an entirely different aircraft.

LightningZ71 · Wed Jul 18, 2018 4:39 pm

No matter which way they go, there's a price to pay. If they choose an upgraded 4th gen design, they will suffer the reduction in capabilities that presents with respect to sensor fusion and RCS. If they go with an all new design, there will be considerable development costs and time involved. If they go with the LM proposal, they still have a longish lead time and a considerable amount of lead time, though maybe not as bad as all new.

The Silent Eagle may actually have the best overall cost profile here with a reasonable timeframe of delivery, but it's not going to be a long term platform for them. Assuming that they can also slow roll a long term development project for its replacement, and get reasonable prices on the Silent Eagle/2040 model, that could be a reasonable route for them to take.

I wonder if Boeing could do a version of the F-15 with the PW F-135-100 instead of the PW-F100-229? It's only slightly longer, and it's outside dimensions are the same as or smaller than the 100. While it's additional thrust may not be needed as much, having a common engine for both the F-15 and the F-35 might be a desirable thing and help offset the upkeep costs of both programs. I can see that working as an advantage for the Silent Eagle in any future sales campaigns as well, especially as the F-35 continues to spread around the world.

Ozair · Thu Nov 08, 2018 10:09 pm

Discussions continue within Japan about the plans and direction for the F-2 replacement. Japanese industry involvement is a huge factor in the development and acquisition of the aircraft.

LDP, Defense Ministry tussle over plan for new fighter jet

With Finance Ministry officials lurking in the background, hawkish lawmakers in the ruling Liberal Democratic Party continue to battle the Defense Ministry over development of the next-generation fighter jet to replace the F-2.

The LDP lawmakers’ initial plan to have development conducted entirely by Japanese companies was scrapped because of expected high costs and possible engineering pitfalls.

But they have not given up the fight, and are now arguing that Japanese companies should play a leading role in any joint development of the new fighter jet.

However, Finance Ministry officials want to keep spending under control no matter what decision is made on the development project.

The F-2 was jointly developed with the United States and first deployed in fiscal 2000. The shelf life of the fighters is expected to expire around 2030.

The Defense Ministry initially had three options for the next-generation fighter jet: to fully develop it domestically; to develop it jointly with other nations; or to extend the life of the F-2 through various modifications.

The third option was jettisoned because modifications alone would not obtain the required capabilities.

As for full domestic development, Finance Ministry officials said it would be too expensive.

That left joint development as the course taken by the Defense Ministry, but the LDP members are not taking that decision lying down.

At a study session held on Nov. 6, LDP lawmakers discussed a proposal for submission to the Defense Ministry, saying that even with joint development, Japanese companies had to play a leading role.

Those lawmakers want to ensure Japanese defense industry companies secure their share of the profits and to pass on the technological foundation that has been created through past development of fighter jets.

They still have in mind the Defense Ministry’s development of a prototype jet dubbed the X-2, which was confirmed to have high stealth and engine capabilities.

More than 200 companies took part in the X-2 project, including Mitsubishi Heavy Industries Ltd., and 93 percent of the prototype was made in Japan.

The Defense Ministry, however, has already received responses from three foreign companies after a request for information (RFI) was issued.

One proposal submitted by Lockheed Martin Corp. of the United States was a hybrid model that would combine the stealth capabilities of its F-35 jet onto the body of the F-22, considered the world’s strongest fighter jet.

Moreover, Lockheed Martin’s proposal said Japanese companies would be given responsibility for more than half of the development and production work.

The other proposals from abroad were submitted by Boeing Co., also from the United States, and Britain’s BAE Systems Plc.

Regardless of which fighter jet is developed, Finance Ministry officials will be casting a sharp eye to ensure costs do not balloon.

The budget for the new fighter jet is expected to be worth trillions of yen. Such spending would come on top of six straight years of increases in the defense budget.

The initial figure for defense spending in the current fiscal year was 5.191 trillion yen ($46 billion).

Because payments must be made on expensive equipment contracted in the past, only about 1 trillion yen a year in the defense budget can be freely used for new projects.

And there is always the possibility that development expenses and manufacturing costs will increase.

“In order to keep expenses down, there has to be other ways of pursuing the development of the jet and placing the orders for the jets,” a Finance Ministry official said.

http://www.asahi.com/ajw/articles/AJ201811070038.html

DigitalSea · Thu Nov 08, 2018 10:39 pm

A joint venture to fund a revamped F-22 that utilizes the best of both the F-22/F-35/B-21 tech worlds with an export version for Japan and other ally nations would be great. Maybe even a 2-seater variant that allows for a weapons officer to utilize long range UCAVs. Focus being on the Western Pacific theater.

RJMAZ · Fri Nov 09, 2018 1:29 am

It is great that Japan realise that you can't do it alone. Hopefully the French and Germans come to the same conclusion.

The development cost must be divided over the number of aircraft purchased to get the true aircraft cost. Development costs of new high tech prograns are growing exponentially so it might end up being 5 times the price of an off the shelf product that covers 90% of the KPI's.

In this case you would have to have a long hard think about the local industrial value. Do they just buy more F-35's and fight for more industrial share of the program.

Most countries have learnt the hard way on how to do a joint program. I'm sure any future joint program wont make the same mistake. Set industrial share, no mission creep, realistic performance versus risk and a minimum purchase quantity.

This might be unlikely but a joint project with Lockheed could result in a 4th variant of the F-35. Engine thrust can be easily increased if you are willing to sacrifice durability and increase maintenance cost. With any engine you can choose a compromise between thrust and fuel efficiency by selecting a different bypass ratio. They could put in an engine with 20% more thrust, add a F-35c sized but non folding wing and add a small stretch to the fuselage. It could in theory keep say 50% commonality with the family. It could in theory have the speed and acceleration of the F-35A but with 25+% range.

Ozair · Fri Nov 09, 2018 2:11 am

RJMAZ wrote:

This might be unlikely but a joint project with Lockheed could result in a 4th variant of the F-35. Engine thrust can be easily increased if you are willing to sacrifice durability and increase maintenance cost. With any engine you can choose a compromise between thrust and fuel efficiency by selecting a different bypass ratio. They could put in an engine with 20% more thrust, add a F-35c sized but non folding wing and add a small stretch to the fuselage. It could in theory keep say 50% commonality with the family. It could in theory have the speed and acceleration of the F-35A but with 25+% range.

That was my suggestion on the previous page. It builds on all the current knowledge of the platform while customising an in production airframe for a specific customer. Japan could go as far as be the only prodution line for this variant and potentially see export success for those seeking an air superiority focused airframe that shares some commonality with their base F-35 fleets.

Obviously LM didn't propose this but sought an F-22 derivative. It would be nice to see what the Japanese thought of this concept.

checksixx · Sat Nov 10, 2018 2:50 am

They should have funded the research for an F-22 export variant. That's what they wanted, but they just wanted to buy them outright. Unfortunately, there was no export model approved and they thought if they kept pushing, they'd just get it. They were wrong.

estorilm · Mon Nov 12, 2018 3:52 pm

checksixx wrote:
They should have funded the research for an F-22 export variant. That's what they wanted, but they just wanted to buy them outright. Unfortunately, there was no export model approved and they thought if they kept pushing, they'd just get it. They were wrong.

What.. initially? It was fairly clear from the start that there would be no export potential for the original F-22. At first it wasn't even worth asking, as the worlds premier air superiority fighter.. then after the production cuts and a decade had passed by.. they attempted again which got the congressional ban on exports. I don't think it was ever an option - plus by then, it was VERY important to secure as many orders for the JSF / F-35 as possible, for with Japan placed a decent-sized order.

I don't really think anyone made the wrong move here. Time continues on, and one of our allies now seeks an uncompromising fighter/interceptor to address new and emerging areal threats - just a different situation now. I do think LM can deliver, but Japan will need to shell out some historic mulah first.

texl1649 · Mon Nov 12, 2018 4:23 pm

Ozair wrote:
RJMAZ wrote:

This might be unlikely but a joint project with Lockheed could result in a 4th variant of the F-35. Engine thrust can be easily increased if you are willing to sacrifice durability and increase maintenance cost. With any engine you can choose a compromise between thrust and fuel efficiency by selecting a different bypass ratio. They could put in an engine with 20% more thrust, add a F-35c sized but non folding wing and add a small stretch to the fuselage. It could in theory keep say 50% commonality with the family. It could in theory have the speed and acceleration of the F-35A but with 25+% range.

That was my suggestion on the previous page. It builds on all the current knowledge of the platform while customising an in production airframe for a specific customer. Japan could go as far as be the only prodution line for this variant and potentially see export success for those seeking an air superiority focused airframe that shares some commonality with their base F-35 fleets.

Obviously LM didn't propose this but sought an F-22 derivative. It would be nice to see what the Japanese thought of this concept.

I disagree that it would be easy to grow thrust 20 percent with a simple/rational trade off in service costs. However, if they do need more thrust and seek savings, the logical answer (as for the USAF/others) might be to compete the engine needs between GE/PW again. With more power, and a non VTOL requirement, a Japanese derivative F-35 with a greater wing size could truly be of interest. Perhaps they'd even agree to let Mitsu/Fuji build the wings and ship over the fuselages to be assembled there.

Ozair · Mon Nov 12, 2018 8:25 pm

texl1649 wrote:

I disagree that it would be easy to grow thrust 20 percent with a simple/rational trade off in service costs.

It is not only easy, it is essentially already defined. For starters the engine has already been tested to that level,

Pratt & Whitney is upping the ante in the ongoing F-35 Joint Strike Fighter engine war by revealing the F135 has achieved combat-rated thrust 20% higher than the specification.

http://aviationweek.com/aw/generic/stor ... line=Pratt

P&W have already developed the Growth Option One package which provides

These new technologies offer a 5 to 6 percent fuel-burn improvement and a thrust bump of 6 to 10 percent over the F135’s 40,000-pound validated maximum-thrust, throughout the F-35’s flight envelope.

https://www.ainonline.com/aviation-news ... nt-pathway

Growth Option 2 adds additional functionality and improvements to that and is likely to be available by 2023/24

texl1649 wrote:
However, if they do need more thrust and seek savings, the logical answer (as for the USAF/others) might be to compete the engine needs between GE/PW again.

While it is debatable as to whether the F100/F110 competition actually delivered any real savings to the USAF this competition is already going on but not with the F136. Both companies are working to USAF contracts for the AETP,

A $437 million contract modification awarded to GE Aviation on 29 June also draws the first sharp line between an ongoing effort to develop a 45,000lb-thrust adaptive engine replacement for the F-35 fleet and a follow-on series of engines designed for the still-undefined aircraft that will replace the Lockheed F-22.
Pratt & Whitney, the powerplant supplier for the F-35 and F-22, also is expected to receive a similarly sized contract modification to develop a competing engine design for a future air superiority aircraft.

https://www.flightglobal.com/news/artic ... ut-450053/
The AETP is intended to fit the F-35 and will likely be a candidate for the LRS-B and the USAF’s 6th gen fighter project. It is a significant contract to win!

texl1649 wrote:
a Japanese derivative F-35 with a greater wing size could truly be of interest. Perhaps they'd even agree to let Mitsu/Fuji build the wings and ship over the fuselages to be assembled there.

Japan would likely expect production of the aircraft given they already have a production line for Japanese F-35s. I expect the wing swept angle would need to change as well, likely from 35 degrees on the F-35 closer to the 42 degrees on the F-22. This would entail a more circumstantial development test program but not out of the realm of possibility and certainly nowhere near the cost of certifying a whole new F-22 with F-35 hardware/software/technology.

estorilm · Mon Nov 12, 2018 9:31 pm

Ozair wrote:
texl1649 wrote:

I disagree that it would be easy to grow thrust 20 percent with a simple/rational trade off in service costs.

It is not only easy, it is essentially already defined. For starters the engine has already been tested to that level,
Pratt & Whitney is upping the ante in the ongoing F-35 Joint Strike Fighter engine war by revealing the F135 has achieved combat-rated thrust 20% higher than the specification.

http://aviationweek.com/aw/generic/stor ... line=Pratt

P&W have already developed the Growth Option One package which provides
These new technologies offer a 5 to 6 percent fuel-burn improvement and a thrust bump of 6 to 10 percent over the F135’s 40,000-pound validated maximum-thrust, throughout the F-35’s flight envelope.

https://www.ainonline.com/aviation-news ... nt-pathway

Growth Option 2 adds additional functionality and improvements to that and is likely to be available by 2023/24

texl1649 wrote:
However, if they do need more thrust and seek savings, the logical answer (as for the USAF/others) might be to compete the engine needs between GE/PW again.

While it is debatable as to whether the F100/F110 competition actually delivered any real savings to the USAF this competition is already going on but not with the F136. Both companies are working to USAF contracts for the AETP,
A $437 million contract modification awarded to GE Aviation on 29 June also draws the first sharp line between an ongoing effort to develop a 45,000lb-thrust adaptive engine replacement for the F-35 fleet and a follow-on series of engines designed for the still-undefined aircraft that will replace the Lockheed F-22.
Pratt & Whitney, the powerplant supplier for the F-35 and F-22, also is expected to receive a similarly sized contract modification to develop a competing engine design for a future air superiority aircraft.

https://www.flightglobal.com/news/artic ... ut-450053/
The AETP is intended to fit the F-35 and will likely be a candidate for the LRS-B and the USAF’s 6th gen fighter project. It is a significant contract to win!

texl1649 wrote:
a Japanese derivative F-35 with a greater wing size could truly be of interest. Perhaps they'd even agree to let Mitsu/Fuji build the wings and ship over the fuselages to be assembled there.

Japan would likely expect production of the aircraft given they already have a production line for Japanese F-35s. I expect the wing swept angle would need to change as well, likely from 35 degrees on the F-35 closer to the 42 degrees on the F-22. This would entail a more circumstantial development test program but not out of the realm of possibility and certainly nowhere near the cost of certifying a whole new F-22 with F-35 hardware/software/technology.

One of the articles I posted earlier indeed mentioned specific manufacturers for aircraft components - I do believe LM had said Mitsubishi Heavy Industries would be a logical choice for the wings. I think the FAL was still going to be LM.

Ozair · Mon Nov 12, 2018 9:43 pm

estorilm wrote:
One of the articles I posted earlier indeed mentioned specific manufacturers for aircraft components - I do believe LM had said Mitsubishi Heavy Industries would be a logical choice for the wings. I think the FAL was still going to be LM.

That is based on a restarted F-22 production line though, not an “enhanced” F-35 concept we are discussing which has, as far as we can tell, never been proposed to Japan.

RJMAZ · Mon Nov 12, 2018 9:56 pm

Wing sweep wouldn't have to be changed to provide true supercruise mach 1.5 capability.

The problem with wing sweep is that all the body joins and doors are aligned. Changing wing sweep would require a full redesign. Even a fuselage extension would be difficult due to the curved bodylift design.

The supersonic shock cone created from the nose hits the F-35C wingtips earlier than the A model. The F-35C leading edge is further forward and extends further outward. The larger wing of the C model had to be extended both forward and aft to maintain centre of gravity. A 1m fuselage extension just aft of the weapon bays would allow the wings leading edge to be at the same position of the A model with the area of the C model. Making the wing tips thinner without the wing folding mechanism would reduce drag when the shock cone hits it. Also a further 1m extension just behind the cockpit where the shape is quite simple would move the shock cone further forward.

The nose extension would be allow the main centre fuel tank to be larger. You would probably be looking at a 16T empty weight with 10T fuel capacity. With an engine with 20% increased thrust it would be getting close to the F-22 kinematics.

Ozair · Mon Nov 12, 2018 10:49 pm

RJMAZ wrote:
Wing sweep wouldn't have to be changed to provide true supercruise mach 1.5 capability.
The problem with wing sweep is that all the body joins and doors are aligned. Changing wing sweep would require a full redesign. Even a fuselage extension would be difficult due to the curved bodylift design.
The supersonic shock cone created from the nose hits the F-35C wingtips earlier than the A model. The F-35C leading edge is further forward and extends further outward. The larger wing of the C model had to be extended both forward and aft to maintain centre of gravity. A 1m fuselage extension just aft of the weapon bays would allow the wings leading edge to be at the same position of the A model with the area of the C model. Making the wing tips thinner without the wing folding mechanism would reduce drag when the shock cone hits it. Also a further 1m extension just behind the cockpit where the shape is quite simple would move the shock cone further forward.

The nose extension would be allow the main centre fuel tank to be larger. You would probably be looking at a 16T empty weight with 10T fuel capacity. With an engine with 20% increased thrust it would be getting close to the F-22 kinematics.

Thanks for those, some good points I hadn’t considered.

RJMAZ · Tue Nov 13, 2018 12:22 pm

I designed an advanced F-35 variant in adobe photoshop. The angle from nose to wingtip is lower than the A model which should reduce transonic drag. Commonlity should be over 50%.

estorilm · Tue Nov 13, 2018 2:28 pm

Ozair wrote:
estorilm wrote:
One of the articles I posted earlier indeed mentioned specific manufacturers for aircraft components - I do believe LM had said Mitsubishi Heavy Industries would be a logical choice for the wings. I think the FAL was still going to be LM.

That is based on a restarted F-22 production line though, not an “enhanced” F-35 concept we are discussing which has, as far as we can tell, never been proposed to Japan.

I don't think that's what we've been talking about at all (enhanced F-35) - the only elements you'd want from the F-35 is a wider array of flexibility with sensors and integration, possibly SA. Other than that, everything spec-wise were things only the F-22 could deliver - though Japan did state they wanted additional weapons stores.

It's not a "restarted F-22 production line" - the thing was only built once.. decades ago. There's zero chance it's going to be the same plane, and it wouldn't have any chance at winning the contract if it was.

As a sweetener to the potential deal, Lockheed Martin is reportedly willing to incorporate avionics built by Mitsubishi Electric and a new wing developed by Mitsubishi Heavy Industries onto the aircraft. Even components such as the fuselage that would be built in the United States would incorporate additional Japanese-made hardware.

https://nationalinterest.org/blog/buzz/lockheed-martin-wants-build-super-f-22-raptor-japan-29997
Not the best source, but they're getting info from somewhere - I think this is the one I quoted a while ago. That was the only mention of MHI I had seen though - and it does make perfect sense.

They already have F-35's, I don't think they want a slightly more capable F-35 that costs them BILLIONS to develop, plus LM would have a nearly impossible time selling that to anyone else, AND it may throw a wrench into future sales of the existing F-35. A hybrid F-22 (okay, "upgraded" - let's be honest, there's minimal changes to the airframe concept required, but it's a new model engineering-wise) is a new (and complimentary) product that makes decent sense from many perspectives for LM. It's also a plane which WOULD have great potential demand, especially if the UK has plans to develop the Tempest in the future.

The F-35 is a great multi-role 5th gen F/A aircraft, but some people want (or "need") something more dedicated to air superiority and specifically an interceptor role - something the F-35 is NOT.. even with a thrust bump and a new wing, it's not going to be big enough (for required long-range A2A weapons stores and fuel, large radar) or fast enough (for speed climb, not on a single engine, and certainly zero capability for super-cruise).

texl1649 · Tue Nov 13, 2018 2:31 pm

Thx Ozair and RJMAZ. Couple questions:

checksixx · Tue Nov 13, 2018 8:48 pm

estorilm wrote:
What.. initially? It was fairly clear from the start that there would be no export potential for the original F-22. At first it wasn't even worth asking, as the worlds premier air superiority fighter.. then after the production cuts and a decade had passed by.. they attempted again which got the congressional ban on exports. I don't think it was ever an option - plus by then, it was VERY important to secure as many orders for the JSF / F-35 as possible, for with Japan placed a decent-sized order.

I don't really think anyone made the wrong move here. Time continues on, and one of our allies now seeks an uncompromising fighter/interceptor to address new and emerging areal threats - just a different situation now. I do think LM can deliver, but Japan will need to shell out some historic mulah first.

The F-22 was never banned from exportation, but rather the funding for the production was secured by law from being used to fund an export approved variant. There was serious discussion with them funding that research and development at one time, but they didn't want to do that. A potential way was offered, they declined. They simply defaulted to the F-35.

Ozair · Tue Nov 13, 2018 9:15 pm

estorilm wrote:
I don't think that's what we've been talking about at all (enhanced F-35) - the only elements you'd want from the F-35 is a wider array of flexibility with sensors and integration, possibly SA. Other than that, everything spec-wise were things only the F-22 could deliver - though Japan did state they wanted additional weapons stores.

RJMAZ and I are discussing an enhanced F-35, not the F-22 derivative LM offered to Japan.

estorilm wrote:
They already have F-35's, I don't think they want a slightly more capable F-35 that costs them BILLIONS to develop, plus LM would have a nearly impossible time selling that to anyone else, AND it may throw a wrench into future sales of the existing F-35.

I disagree. Japan have indicated a timeframe of 2030 for the jet to enter service. An enhanced F-35 could be developed, tested, into production and IOC in that timeframe. As for the billions, yes it will obviously cost to develop/test but it will cost Japan to develop whatever they acquire and an enhanced F-35 is likely to be significantly less than an F-22 derivative and also be far more likely to arrive in the timeframe they seek.

I doubt LM would have an issue with future sales given the jet would still be an F-35 variant and share significant commonality with existing aircraft and have had its dev costs paid for by Japan. Therefore the only hitch may be a royalty for any nation who acquired the variant (similar to what the UAE did and sought with the Blk 60 F-16).

LM has thousands of guys working on the F-35 and probably less than 5% of that working on the F-22. The corporate knowledge on the F-35 is currently immense and the ability to directly apply that to a new modification/enhancement program is a low risk effort against the possibility of trying to bring production back of a jet that was designed in the late 80s and will have been out of production for nearly 15 years by the time it has to start again.

estorilm wrote:
A hybrid F-22 (okay, "upgraded" - let's be honest, there's minimal changes to the airframe concept required, but it's a new model engineering-wise) is a new (and complimentary) product that makes decent sense from many perspectives for LM. It's also a plane which WOULD have great potential demand, especially if the UK has plans to develop the Tempest in the future.

The F-35 is a great multi-role 5th gen F/A aircraft, but some people want (or "need") something more dedicated to air superiority and specifically an interceptor role - something the F-35 is NOT.. even with a thrust bump and a new wing, it's not going to be big enough (for required long-range A2A weapons stores and fuel, large radar) or fast enough (for speed climb, not on a single engine, and certainly zero capability for super-cruise).

I think an enhanced F-35 could provide the capabilities required by Japan for an air superiority/interceptor aircraft. The aircraft has a larger internal bay than the F-22, a similar sized radar, would have a greater fuel load than the F-22, be more efficient than an F-22, with the engine enhancements and fuselage plug likely have better acceleration and probably have an acceptable supercruise speed. It is the low risk option.

No one is suggesting this will happen, just that we consider it a more viable and lower risk option than what LM suggested with an F-22/F-35 hybrid.

texl1649 wrote:
Thx Ozair and RJMAZ. Couple questions:
[list][list]Wouldn't adding internal fuel, and pushing the wings back (fuse extension behind cockpit) wind up making it less maneuverable overall at transonic/subsonic speeds?

I don’t think so but I also don’t think high end manoeuvrability is the end all. Noting Japan are essentially seeking an interceptor it would likely be sufficiently manoeuvrable for their needs.

texl1649 wrote:
Why retain the stub wings from the A model at the end, vs. going to 43 ft span but deleting the folding tips?

I think RJAMZ is suggesting to use the C wing. I’m not convinced that is the best option but it would certainly provide more lift and increased fuel load. The smaller A wing would likely be better for climb rate and acceleration.

texl1649 wrote:
Would the AETP engine from pratt possibly incorporate the vectoring tech from the F119 parent for a conventional version?

Noting I have never flown in a fighter aircraft that had thrust vectoring technology I don’t consider it worth the additional weight and expense. If the intent is to increase manoeuvrability then thrust vectoring isn’t needed, if the intent is to potentially improve supersonic performance, as TV suggestions for the Eurofighter suggest, then perhaps it is worth it but would come at a penalty of potentially increased maintenance costs (which reduced fuel use or increased operational capability could potentially offset).

Some info on the Eurofighter intention here, https://www.flightglobal.com/news/artic ... on-333501/ noting the article is over nine years old and no customer has taken up the option.

RJMAZ · Wed Nov 14, 2018 1:14 pm

texl1649 wrote:
Thx Ozair and RJMAZ. Couple questions:
Wouldn't adding internal fuel, and pushing the wings back (fuse extension behind cockpit) wind up making it less maneuverable overall at transonic/subsonic speeds?
Why retain the stub wings from the A model at the end, vs. going to 43 ft span but deleting the folding tips?
Would the AETP engine from pratt possibly incorporate the vectoring tech from the F119 parent for a conventional version?

A lot of thought has gone into that design. It is worth having a closer look at all of the subtle changes. It is really the only way to make a faster F-35 version while maintaining commonality.

Subsonic agility and acceleration would be on par with the F-35A. Transonic drag would be reduced significantly which would improve the most tactically significant mach 0.8 to 1.2 acceleration even with the same thrust level. The F-35D would cruise at a higher speed than the F-35A without afterburner. I estimate mach 1.3 with the current standard engine. Mach 1.4 with a 10% thrust boost and mach 1.5 with a 20% thrust boost.

Using the larger horizontal stabiliser from the C model should help agility with the added weight.

The wing for the F-35D would be completely unique. A stubby wing like the F-35A but scaled up in size and slightly thinner. An important feature is the leading edge extension it would be twice the size/length of the F-35A. The F-35C has no leading edge extension as the front edge of the wing starts further forward. The leading edge extension provides forward lift as angle of attack increases.

Removing the wing fold saves weight, using the stubby wingtip reduces transonic drag. The wingtips extend into the supersonic shock cone created from the nose, cropping them off like the A model and making the outter section of the wing thinner will help. The reason the F-35C has poor transonic acceleration is because more of the wing tips extends into the supersonic shock cone from the nose.

Thrust vectoring on the F-35D wouldn't be required. Dogfights at very slow speed is unlikely.

With the engine, the F-35 is limited to a set fan diameter. There are three ways the engine thrust could be increased.
1) Decreasing bypass ratio allows more hot core thrust. Fuel burn however becomes worse.
2) Run the engine hotter using new turbine materials.
3) Run the engine hotter sacrificing engine life. Most engines already have a wartime setting that reduces engine life.

A combination of all three could allow a unique engine to be fitted to this F-35D model. Reduced fuel burn would be acceptable due to the extra internal fuel. Reduced engine life could be acceptable to achieve higher performance as it is an air dominance platform. Each one could increase thrust by 10% over the current F135 engine bringing a total increase of 30%. That is up to 55,000lb of thrust in the size of the current engine.

With the same fuel fraction the F-35D would have a thrust to weight ratio equal to the F-22. The perfect long range interceptor or air dominance aircraft. This would be perfect for Japan.

estorilm · Wed Nov 14, 2018 7:48 pm

Ozair wrote:
estorilm wrote:
A hybrid F-22 (okay, "upgraded" - let's be honest, there's minimal changes to the airframe concept required, but it's a new model engineering-wise) is a new (and complimentary) product that makes decent sense from many perspectives for LM. It's also a plane which WOULD have great potential demand, especially if the UK has plans to develop the Tempest in the future.

The F-35 is a great multi-role 5th gen F/A aircraft, but some people want (or "need") something more dedicated to air superiority and specifically an interceptor role - something the F-35 is NOT.. even with a thrust bump and a new wing, it's not going to be big enough (for required long-range A2A weapons stores and fuel, large radar) or fast enough (for speed climb, not on a single engine, and certainly zero capability for super-cruise).

I think an enhanced F-35 could provide the capabilities required by Japan for an air superiority/interceptor aircraft. The aircraft has a larger internal bay than the F-22, a similar sized radar, would have a greater fuel load than the F-22, be more efficient than an F-22, with the engine enhancements and fuselage plug likely have better acceleration and probably have an acceptable supercruise speed. It is the low risk option.

No one is suggesting this will happen, just that we consider it a more viable and lower risk option than what LM suggested with an F-22/F-35 hybrid.

I love the F-35, but I think you've got the beer goggles on when it comes to its' capacity to be modified into anything resembling an interceptor. Especially with its weapons bay. Weight-wise its capacity is large, but dimentionally I've seen the F-22's main bay, and it looks like you could park a car inside of it - would like to see your info on the F-35 being larger. I don't see how that's even remotely possible. It's also oriented differently - it would require modifications to allow the "depth" to be more useful for A2A weapons alone, though that's certainly something they could work around.

The main problem is that it just doesn't have the power - not only that, but I don't see how it ever could. Even an AETP engine won't have enough power to supercruise. I've mentioned a few times that even with the supercruise-optimized engines (which the BPR of the F-135 is NOT) for the Raptor, and a low-drag airframe, they still made last-second changes to the design to allow supercruise. Someone was quoted as saying without the vertical tail fin relocation last minute, the fighter would NOT have been capable of supercruise. If that's true, then the F-35 isn't even on the same planet for such capabilities, as every inch of the plane was designed without that feature (or anything M2.0+) in mind - but maybe we're just assuming that it isn't a real priority for the Japanese. I think it's very valuable for an interceptor though, and would be a let-down for procurement if they're getting a new fighter that's STILL not really "top of the line".

Also - I FINALLY found one of the original sources for the information which I've been primarily going off of for the thread creation. (translated) - https://blogos.com/article/294868/?p=1
According to the Yomiuri Shimbun, the "required performance" of the F2 successor transmitted to the US and the UK are (1) a small unmanned aerial vehicle as a "slave" (2) 8 interior air-to-air missiles doubled by F35A 3) Maximum speed equivalent to F2 (Mach 2) (3) Ranging distance equal to or higher than F35A · Stealth property · Radar detection distance etc. Air-to-ship missiles are supposed to assume external equipment according to operation.
I've also seen multiple sources claiming supercruise and "a large, twin-engine design" as likely requirements. Personally I think that goes without saying, based on the requirements listed above though.

RJMAZ wrote:
With the same fuel fraction the F-35D would have a thrust to weight ratio equal to the F-22. The perfect long range interceptor or air dominance aircraft. This would be perfect for Japan.

No offense, but you just connected a TON of "unconnectable" dots in my opinion. I don't think you can get a 30% increase in performance out of that engine, and even if you could - I SERIOUSLY doubt Pratt would be interested. You're no longer talking about a small update, but rather a fairly exotic engine which they will only make a few of. It's also been mentioned that they'd likely prefer to use domestic power, but in any form that may be impossible even if it's a more conventional design (however a twin engine aircraft gives you more wiggle-room).

The above quote for specs mentioned a match in range to the F-35. I don't care how much you change the wing - there's a 0% chance that you can increase the thrust 30% and maintain the same range. Oh also you're going to need (significantly) more internal weapons space. There's no way.

Also (though this is very difficult to calculate or quantify) - I don't think the F-35's airframe is capable (certainly not optimized) for ~M2.0 speeds.

I mean at the end of the day, think about it this way - the F-22 was DESIGNED to do what Japan needs a plane to do, and the result was a large, twin-engined aircraft with ~70,000lbs thrust. Russia had similar requirements which resulted in a similar size/power plane design.

You're just asking a small plane to do a LOT of large plane "stuff".

Ozair · Wed Nov 14, 2018 10:08 pm

estorilm wrote:
I love the F-35, but I think you've got the beer goggles on when it comes to its' capacity to be modified into anything resembling an interceptor.

Lol. I again state this isn’t a validated concept by LM, just an exercise in looking at what Japan wants and how it could be fulfilled instead of the obvious.

estorilm wrote:
Especially with its weapons bay. Weight-wise its capacity is large, but dimentionally I've seen the F-22's main bay, and it looks like you could park a car inside of it - would like to see your info on the F-35 being larger. I don't see how that's even remotely possible. It's also oriented differently - it would require modifications to allow the "depth" to be more useful for A2A weapons alone, though that's certainly something they could work around.

An interesting position. The F-35 weapons bays are longer and deeper against shallower, wider and shorter bays on the F-22. Dimensions on F-22, http://www.f-16.net/forum/viewtopic.php?t=8164

F-22

F-35

We know the F-22 is limited to 1,000lb JDAMs while the F-35 has the capacity for 2,000lb weapons internally. The F-35, while currently capable of only four AIM-120s internally will carry six internally the same as the F-22 likely in late Blk 4 or start of Blk 5. The F-35 requires a new launcher to undertake the 6 AAM mod because the bay is deeper but not as wide.

estorilm wrote:
The main problem is that it just doesn't have the power - not only that, but I don't see how it ever could. Even an AETP engine won't have enough power to supercruise. I've mentioned a few times that even with the supercruise-optimized engines (which the BPR of the F-135 is NOT)

I really don’t see a limitation with the engine.

estorilm wrote:
for the Raptor, and a low-drag airframe, they still made last-second changes to the design to allow supercruise. Someone was quoted as saying without the vertical tail fin relocation last minute, the fighter would NOT have been capable of supercruise.

I am very sceptical of the claim that a single move of the vertical stabilizer drastically changed the capability of the jet to supercruise.

estorilm wrote:
If that's true, then the F-35 isn't even on the same planet for such capabilities, as every inch of the plane was designed without that feature (or anything M2.0+) in mind - but maybe we're just assuming that it isn't a real priority for the Japanese. I think it's very valuable for an interceptor though, and would be a let-down for procurement if they're getting a new fighter that's STILL not really "top of the line".

So that is a good question, is the requirement for “supercruise” or “supersonic” performance? They are obviously two very different things.

estorilm wrote:
Also - I FINALLY found one of the original sources for the information which I've been primarily going off of for the thread creation. (translated) - https://blogos.com/article/294868/?p=1
According to the Yomiuri Shimbun, the "required performance" of the F2 successor transmitted to the US and the UK are (1) a small unmanned aerial vehicle as a "slave" (2) 8 interior air-to-air missiles doubled by F35A 3) Maximum speed equivalent to F2 (Mach 2) (3) Ranging distance equal to or higher than F35A · Stealth property · Radar detection distance etc. Air-to-ship missiles are supposed to assume external equipment according to operation.
I've also seen multiple sources claiming supercruise and "a large, twin-engine design" as likely requirements. Personally I think that goes without saying, based on the requirements listed above though.

Think about this for a moment though, the F-2 is a single engine jet that doesn’t fly Mach 2 (with a weapons load), doesn’t have a large weapons load, carries ASCMs external and has a shorter range than the F-35. I don’t see two engines are being a requirement for an F-2 replacement. If the Japanese consider the current F-35 an F-2 replacement then what comes later replaces the F-15. Either way, constraining the design to two engines seems pointless. All the rest will essentially be accomplished by a regular F-35 while an enhanced F-35 overcomes pretty much all the issues except twin engines.

estorilm wrote:
No offense, but you just connected a TON of "unconnectable" dots in my opinion. I don't think you can get a 30% increase in performance out of that engine, and even if you could - I SERIOUSLY doubt Pratt would be interested. You're no longer talking about a small update, but rather a fairly exotic engine which they will only make a few of. It's also been mentioned that they'd likely prefer to use domestic power, but in any form that may be impossible even if it's a more conventional design (however a twin engine aircraft gives you more wiggle-room).

The AETP is coming, it will power the US 6th gen aircraft and is being designed as F135 sized for a specific reason. It will also likely power the B-21 so straight up you have the 6th gen aircraft, probably a third of F35 production and likely most/all of B-21 production so potentially upwards of 2000 engines. There is clearly money in that and P&W is well aware that GE is chomping at the bit to win that future engine contract.

estorilm wrote:
The above quote for specs mentioned a match in range to the F-35. I don't care how much you change the wing - there's a 0% chance that you can increase the thrust 30% and maintain the same range. Oh also you're going to need (significantly) more internal weapons space. There's no way.

As already stated in the thread the F135 growth option one and two come with both increased thrust and reduced fuel burn, it is not a trade-off between the two.

The requirements you state talk of eight internal air to air weapons but does it state what size? The important thing to note is we have yet to see a 5th gen missile emerge for the 5th gen aircraft. That is expected in the mid 2020s and all indications are it will be smaller and specifically designed to meet the range of existing weapons while increasing internal loads. That sees the aircraft move to an 8-10 weapon load out. A very conceivable load out for the enhanced F-35 could be one Japanese Meteor and three to four 5th gen missiles per bay.

estorilm wrote:
Also (though this is very difficult to calculate or quantify) - I don't think the F-35's airframe is capable (certainly not optimized) for ~M2.0 speeds.

The aircraft is probably capable of going that speed but appears to be constrained to M1.6 in consideration of materials and maintaining stealth characteristics.

RJMAZ · Wed Nov 14, 2018 10:30 pm

estorilm wrote:
No offense, but you just connected a TON of "unconnectable" dots in my opinion. I don't think you can get a 30% increase in performance out of that engine, and even if you could - I SERIOUSLY doubt Pratt would be interested. You're no longer talking about a small update, but rather a fairly exotic engine which they will only make a few of.

No offense taken but I will help connect the dots for you.

Firstly it is not a F-135 engine. It is a new engine that fits in the same dimensions as the F-135. It will be expensive but a fraction of the price of a cleansheet twin engine fighter.

Pratt has already tested the F-135 to above a 10% thrust increase but simply running it hotter at the expense of reliability. Pratt did not change the bypass ratio or add ceramic matrix turbines both which will add even more power. You dont understand the relationship between bypass ratio and thrust. A CF34 has the same diameter fan as the F-135 but less than half of the dry thrust. An engine with less bypass ratio will have more thrust than the F-135 without using any fancy technology. I can estimate how much extra thrust can be achieved.

30% is definitely possible right now. It could even be a derivative of the GE F136 engine assembled in Japan that gets selected. Reducing the bypass ratio increases the dry thrust by a larger percentage than the wet thrust. You can see this how low pass byass ratio engines get a smaller increase from afterburners. So if supercruise is a requirement a lower byass ratio engine will significantly increase dry thrust for the F-35D.

estorilm wrote:
the above quote for specs mentioned a match in range to the F-35. I don't care how much you change the wing - there's a 0% chance that you can increase the thrust 30% and maintain the same range.

That is not how you calculate range. The F-35D would not require 30% extra thrust to maintain the same speed as the F-35A. This extra thrust provides extra speed. The F-35D would have similar lift to drag ratio and wing loading of the F-35A so the required extra cruising thrust would be based off the weight incresse. As the F-35D weighs approximately 15% more it would then require 15% more dry thrust to cruise at say mach 0.8. As it also carries 15% more fuel then it can sustain 15% more thrust for the same amount of time. Equal range.

With all designs transonic drag increases significantly and then drops down again once supersonic. The size and speed range of this transonic drag increase is connected to the design. A delta wing for example can pass through the transonic with very little spike in drag. The F-35D wing design would mean it has a lower transonic drag peak. At say Mach 1.1 it would require less thrust and less fuel burn than the F-35A despite it being heavier.

estorilm wrote:
Oh also you're going to need (significantly) more internal weapons space. There's no way.

The F-35 has more volume than the F-22. Originally the F-22 could only carry 4 AMRAAM's but they secretly made custom missiles with smaller fins so the F-22 could fit six. The same is happening with the F-35. Expect custom missiles in 10 years time.

estorilm wrote:
I don't think the F-35's airframe is capable (certainly not optimized) for ~M2.0 speeds.

The maximum speed of a fighter depends on the highspeed drag of the air frame and thrust. The F-35D reduces high speed drag and increases thrust. Fast aircraft have maximum wingspan located further aft to keep the wings out of the supersonic shock cone. The F-104 has less sweep than the F-35 but could go extremely fast. The F-35 doesn't need to change its wing sweep. Stretching the nose, mounting the wing further back with larger LERX's WILL increase the speed of the design. I can estimate within maybe 10% but it would definitely reach the supercruise definition.

estorilm wrote:
I mean at the end of the day, think about it this way - the F-22 was DESIGNED to do what Japan needs a plane to do, and the result was a large, twin-engined aircraft with ~70,000lbs thrust. Russia had similar requirements which resulted in a similar size/power plane design.

You're just asking a small plane to do a LOT of large plane "stuff".

At the end of the day you idealize the F-22, but really it is just a compromise of design decisions to achieve a certain goal. It was cancelled for a reason. The F-35D's single engine at 55,000lb thrust would have greater total thrust than the original SU-27 and the latest F-15. At 16T empty it is large fighter.

The airframe changes and second engine would be cheaper than a clean sheet design.

estorilm · Thu Nov 15, 2018 3:43 pm

Ozair wrote:
Lol. I again state this isn’t a validated concept by LM, just an exercise in looking at what Japan wants and how it could be fulfilled instead of the obvious.

Oh I agree - I'm on board with the hypotheticals - I just don't see quite the potential you do

Ozair wrote:
An interesting position. The F-35 weapons bays are longer and deeper against shallower, wider and shorter bays on the F-22. Dimensions on F-22, http://www.f-16.net/forum/viewtopic.php?t=8164

Well that's why I said it would need to be modified to "stack" - and yeah anything over 2000lbs is pointless, especially with a shallow bay and (usually) better / cheaper aircraft for that mission. I'd call that a draw, but I don't however, ever envision 8 AMRAAMs ever fitting in that design (just the 6 for the new block update / launcher system).

Ozair wrote:
I really don’t see a limitation with the engine....
--
So that is a good question, is the requirement for “supercruise” or “supersonic” performance? They are obviously two very different things.

The limitation (as I understand it) is the velocity of the thrust and the BPR of the engine, plus the materials and overall design. You actually mentioned these in your earlier post, and eluded to the changes which would be required to meet M2. It's really a different engine - the changes between the F119 and F135 are dramatic. I realize some are "evolutionary" - but many are performance-oriented.

I see supercruise and supersonic performance as the same thing. Any airframe which is capable of supercruise will have a highly-optimized design for that type of drag/shockwave. I mean come on - a clean Raptor is by all accounts capable of outrunning a clean F-35 (any variant) WITHOUT afterburner. That's just insane to think about. I'd also be VERY curious to see what thrust a Raptor is putting out at full mil power versus full (wet) thrust from an F-35. I'd imagine the results would highlight just how efficient the F-22's design is for (overall) supersonic performance.

Ozair wrote:
I am very sceptical of the claim that a single move of the vertical stabilizer drastically changed the capability of the jet to supercruise.

Didn't think I could find it, but here you are - really fascinating bit of insight into just how "perfect" the Raptor's eventual design really is. :shock:

The tail chase
Once the wings were set with Configuration 614, subsequent configurations dealt with the tail arrangement. “We spent a lot of wind tunnel time looking at the tails,” recalls Lou Bangert, the chief engineer for engine integration from Lockheed. “From late 1987 to early 1988, we were engaged in what we called ‘the great tail chase.’ We knew we would have four tails, but where they would go was a big deal. A small change in location often made a huge difference. We had to look at performance effects, stealth effects, stability and control, and drag at the same time. The tail arrangement and aft end design were important design considerations for all of these effects.”

Wind tunnel results showed an ultra-sensitive relationship between the placement of the vertical tails and the design of the forward fuselage. The interactions could not be predicted accurately by analysis or by computational fluid dynamics. The airflow over the forebody at certain angles of attack affects the control power exerted by the twin rudders on the vertical tails. Getting the airflow right was critical.

The cant and sweep angles of the vertical tails could not be altered too much because such changes increased radar signature. In finding a suitable arrangement, the control system designers were constrained by the radar signature requirements to moving the tail locations laterally or longitudinally and to shrinking or enlarging them while holding the shape essentially constant. By the end of the dem/val phase, the team had accumulated around 20,000 hours in the wind tunnel. A lot of this time was devoted to tail placement studies.

Configuration 614-6, with trapezoidal horizontal and vertical tails, represented the starting point for the tail chase in December 1987. After many intervening configurations, the vertical tails had evolved to a diamond shape by February 1988 in Configuration 630. The wing area was also reduced in Configuration 630. The size of each vertical tail increased by seven square feet in Configuration 631. The rudder size was also increased slightly and the cant angle of the verticals went from thirty degrees to twenty-eight degrees. The prototype design was frozen at this shape (Configuration 1131) in March 1988.

The prototype design was unfrozen at the last minute in May 1988 after the Air Force eliminated the requirement for thrust reversing for short-field operations. The change allowed the team to alter the external mold lines on the aft fuselage and nozzles in the area around the thrust reversers. The trimmed aft end reduced drag significantly. “We never had an airplane with the right supersonic drag until May,” Mullin explains. “We scared the Air Force when we unfroze the prototype design at that late date. The supersonic drag was still too high to supercruise. A team led by Ed Glasgow, our chief flight sciences engineer, redesigned the forebody and aftbody. Suddenly we had acceptable supersonic drag levels that ensured that the airplane would supercruise.”

The final design freeze for the prototype occurred at Configuration 1132 in May 1988. Besides the reshaped forebody and trimmed aft section, the horizontal tails also changed from trapezoidal to diamond in the transition from Configuration 1131 to 1132.

My point here is just to highlight how incredibly difficult it is to achieve high-mach (and even more-so, supercruise) without an aircraft design which factored that in initially (even with already-low drag and immense thrust). Not only was high-mach not a factor in the F-35, but supercruise wasn't a consideration. I personally believe it would require dramatic changes from the ground up, but we would literally need an engineer to chime in on that one.

Ozair wrote:
Think about this for a moment though, the F-2 is a single engine jet that doesn’t fly Mach 2 (with a weapons load), doesn’t have a large weapons load, carries ASCMs external and has a shorter range than the F-35. I don’t see two engines are being a requirement for an F-2 replacement. If the Japanese consider the current F-35 an F-2 replacement then what comes later replaces the F-15. Either way, constraining the design to two engines seems pointless. All the rest will essentially be accomplished by a regular F-35 while an enhanced F-35 overcomes pretty much all the issues except twin engines.

Fair enough, but they want an upgrade - they have F-15s and F-35s, and clearly plan on spending billions - what does that point to? This implies a clear increase in capability and performance (over both of those) - not just an adaptation. As I've stated previously, there are some LARGE constraints due to a single engine. At some point if you want this thing to really perform (BVR kinematic performance, fast intercepts, etc) there's just no way around it.

Ozair wrote:
The AETP is coming, it will power the US 6th gen aircraft and is being designed as F135 sized for a specific reason. It will also likely power the B-21 so straight up you have the 6th gen aircraft, probably a third of F35 production and likely most/all of B-21 production so potentially upwards of 2000 engines. There is clearly money in that and P&W is well aware that GE is chomping at the bit to win that future engine contract.

Both the aircraft you mention are within the realm of the original design specs for the engine - one of which is purely subsonic, the other sub-M2. The 2000 engines you mention have zero requirement for M2+ performance or supercruise, and (IMHO) can be immediately counted out of providing that capability. Pratt will focus on fuel efficiency, a thrust bump, and reliability. Mission profile will almost certainly remain the same. The thrust will change some performance specs of the current F-35 design, especially regaining energy after high AoA maneuvers which will be great - and combat radius will obviously jump up quite a bit. It'll be a great engine, but I don't see it allowing you do really do anything much different with the design of the plane itself. Maybe the new wing you speak of and removal of the vertical tails? Longer nose for increased length/lower drag/more fuel... Would need 3D vectoring to regain A2A performance. That could be a cool plane though.

Ozair wrote:
The aircraft is probably capable of going that speed but appears to be constrained to M1.6 in consideration of materials and maintaining stealth characteristics.

That's one factor, though wasn't the RAM process and material transferred to the F-22 shortly after the F-35 came out? I thought I remembered reading something about that. Again my largest concern is just the angles, geometry of every inch of the plane, intake ducts, etc.

That's another question - the Diverterless Supersonic Inlet LM "pioneered" for the F-35 is said to max out around M2. I'm sure specifics will be impossible to get, but the top speed numbers we see may have something to do with the DSI design - that may need to revert back to a ramp-style inlet for any significant speed increase - although the J-20 (which uses a DSI) is said to reach M2.5 (not that I believe much of anything about those specs).

Cheers,
Alex

texl1649 · Thu Nov 15, 2018 9:09 pm

I'd just like to thank the last three posters, esp. RJMAZ and ozair, for a very interesting discussion. I'd not considered many of these points at all, and find the engine/drag/supercruise/interceptor discussion very good to read through.

estorilm · Fri Nov 16, 2018 5:16 pm

texl1649 wrote:
I'd just like to thank the last three posters, esp. RJMAZ and ozair, for a very interesting discussion. I'd not considered many of these points at all, and find the engine/drag/supercruise/interceptor discussion very good to read through.

Ouch!

RJMAZ · Sat Nov 17, 2018 2:07 am

estorilm wrote:
[
Well that's why I said it would need to be modified to "stack" - and yeah anything over 2000lbs is pointless, especially with a shallow bay and (usually) better / cheaper aircraft for that mission. I'd call that a draw, but I don't however, ever envision 8 AMRAAMs ever fitting in that design (just the 6 for the new block update / launcher system).

The F-35 main bay is deeper. If new missiles are narrower it could in theory allow two missiles deep. That is 8-10 missiles.

estorilm wrote:
The limitation (as I understand it) is the velocity of the thrust and the BPR of the engine, plus the materials and overall design. You actually mentioned these in your earlier post, and eluded to the changes which would be required to meet M2. It's really a different engine - the changes between the F119 and F135 are dramatic. I realize some are "evolutionary" - but many are performance-oriented.

I see supercruise and supersonic performance as the same thing. Any airframe which is capable of supercruise will have a highly-optimized design for that type of drag/shockwave.

Supercruise and supersonic performance dont go hand in hand.

Firstly you have it completely opposite a high bypass engine in afterburner will actually have a higher exhaust velocity than low byass engine in afterburner. The afterburner increases exhaust velocity significantly and the higher bypass engine has more fresh air for the afterburner to use.

At dry thrust however the low bypass engine will have much faster exhaust velocity which is required for supercruise.

The Tornado and B-1b engines have the highest bypass ratio for an afterburning engine. As a result they get a massive 75% thrust increase in afterburner, their dry thrust is a very low percentage of maximum thrust which is bad if you want ro supercruise.

The French m88 has a very low bypass ratio so it gains only 50% extra thrust from its afterburner. You can check multiple engines and you will find the byass ratio is linked to the dry thrust percentage.

The F-35 was fitted with a slightly higher byass ratio to provide excellent subsonic endurance but with afterburner it still provides excellent supersonic acceleration. Its mission profile simply wanted more time spent subsonic so the engine was built with the most suitable compromise of bypass ratio. The Aerodynanics of the F-35A was also limited by having to share a lot of parts with the other models.

If you changed the mission profile to include longer period at supersonic speed and allowed more unique parts to be introduced into the F-35D then you will gain performance.

A lower byass ratio engine in the F-35 would increase the percentage of dry thrust relative to max thrust. So you might gain 30% more dry thrust with more exhaust velocity but only gin 15% max afterburner thrust. It is this extra dry thrust that suits the Japan proposal.

45272455674 · Sat Nov 17, 2018 5:16 am

RJMAZ wrote:
The F-35D's single engine at 55,000lb thrust would have greater total thrust than the original SU-27 and the latest F-15. At 16T empty it is large fighter.

The airframe changes and second engine would be cheaper than a clean sheet design.

When was this F35D built? And where is it flying? Can you show me this 55,000lb thrust engine?

Ozair · Sun Nov 18, 2018 5:00 am

cpd wrote:
RJMAZ wrote:
The F-35D's single engine at 55,000lb thrust would have greater total thrust than the original SU-27 and the latest F-15. At 16T empty it is large fighter.

The airframe changes and second engine would be cheaper than a clean sheet design.

When was this F35D built? And where is it flying? Can you show me this 55,000lb thrust engine?

Just concepts and no one is claiming otherwise. There is scope for these types of enhancements through given the dev work that is already being funded by for example the USAF on the AETP.

RJMAZ · Sun Nov 18, 2018 7:12 am

Pratt isn't standing still either. The last thing they want is for GE to get the contract when it comes to deciding who gets the AETP.

They have two improved versions of the F135 available called Growth option 1.0 and 2.0.

The version 2 has already been tested to 48,700lb of thrust and burns less fuel. The AETP might not even get a shot on the F-35 if Pratt keeps improving the F135. The improved F135 will probably be the lowest risk option. The core can be swapped out during maintenance to gain the extra performance.

GE will have to invest a lot of resources to get back on the F-35. If the F-35D idea required a lower bypass ratio engine then a clean sheet design would be best. This could favour GE in partnership with a Japanese company.

45272455674 · Wed Nov 28, 2018 1:13 am

Ozair wrote:
cpd wrote:
RJMAZ wrote:
The F-35D's single engine at 55,000lb thrust would have greater total thrust than the original SU-27 and the latest F-15. At 16T empty it is large fighter.

The airframe changes and second engine would be cheaper than a clean sheet design.

When was this F35D built? And where is it flying? Can you show me this 55,000lb thrust engine?

Just concepts and no one is claiming otherwise. There is scope for these types of enhancements through given the dev work that is already being funded by for example the USAF on the AETP.

Oh that engine, there are a number of applications for it.

RJMAZ · Wed Nov 28, 2018 2:54 am

cpd wrote:
Oh that engine, there are a number of applications for it.

As much as I like that engine it is still a compromise.

You could still produce an engine with either greater thrust or better fuel efficiency in the same physical engine size. It is not a magic engine.

When that third stream of air opens the bypass ratio is increased slightly. The downside is the core no longer sees that air. The core is no longer running at peak efficiency. An engine with a smaller core running at peak efficiency and larger but fixed byass ratio will always have better fuel burn.

To put this into perspectice you could have two engine options at either extreme for the F-35, a high speed engine and a long range engine.

The specs might look like this:

High speed engine
0.2 byass ratio
30,000lb dry thrust, 45,000lb wet thrust

Long range engine
1:1 bypass ratio
25,000lb dry thrust, 45,000lb wet thrust

The wet thrust would be similar for both as the long range engine has more bypass air to get a bigger gain from the afterburner. The long range engine would burn approx 20% more fuel at full afterburner while producing the same thrust.

The Long range engine would however burn nearly 20% less fuel when both are producing 25,000lb of dry thrust.

The high speed engine has greater dry thrust and a much faster exhaust velocity at full dry thrust. The F-35 would easily supercruise with such an engine.

Both engines can still reach the same maximum speed but the Long range engine will have much shorter range while supersonic. So the long range engine would be more suitable for the F-35's performing strike and a perfect F-15E replacement. The high speed engine would be more suitable as a F-22 replacement.

The AETP attempts to reach these two extremes in a single engine but it won't even get half way.

I also wonder why the B-21 would want an AETP as it is not a supersonic platform. The AETP engine on the B-21 would always be flying at max fuel efficiency at the highest bypass ratio. You would be better off just going with long range engine I listed above.

It would be interesting if the B-21 program helps fund a second engine option for the F-35 Family that is designed to maximise range. The various roles and huge production run of the F-35 family could easily justify two engines with different performance profiles. It would be just like the F-16 family with the big mouth GE's but a much greater difference in performance between the two F-35 engines.

estorilm · Wed Nov 28, 2018 1:48 pm

Sorry everyone, getting buried at work and haven't been able to reply with some of my thoughts on things - especially regarding the engine stuff.

IN OTHER NEWS - if you read between the lines here, this latest report could almost immediately shut the door on everything we're discussing in this thread (which was always a possibility, and something I questioned; "they already have the F-35 though?") - perhaps (and I see some logic behind this) it's cheaper and nearly as effective to just get more F-35s, save $$ on commonality, training, and most importantly - no additional development/procurement costs. The extra planes still allow for an increase in defensive force projection that really can't be countered by either Russia nor China, regardless of whatever 5th gens they produce.

Japan Set to Massively Expand F-35 Fleet
Japan is planning to announce a massive purchase of fifth-generation F-35 Joint Strike Fighter aircraft next month in response to Beijing’s military buildup, Japanese media reported Tuesday.

Japan will buy 100 F-35s in a deal worth nearly $9 billion, according to reports.

https://sputniknews.com/military/201811271070181134-japan-set-massive-expand-f-35/

:shock:

Sorry folks, it's been fun though!

jaehaerys48 · Wed Nov 28, 2018 2:11 pm

A bit sad (it's always nice to see greater variety), but a sensible move. The JASDF will continue to be one of the best air forces around with this purchase.

Ozair · Wed Nov 28, 2018 8:25 pm

estorilm wrote:
Sorry everyone, getting buried at work and haven't been able to reply with some of my thoughts on things - especially regarding the engine stuff.

IN OTHER NEWS - if you read between the lines here, this latest report could almost immediately shut the door on everything we're discussing in this thread (which was always a possibility, and something I questioned; "they already have the F-35 though?") - perhaps (and I see some logic behind this) it's cheaper and nearly as effective to just get more F-35s, save $$ on commonality, training, and most importantly - no additional development/procurement costs. The extra planes still allow for an increase in defensive force projection that really can't be countered by either Russia nor China, regardless of whatever 5th gens they produce.

I don’t think this has shut the door on some type of Japanese development of a 5th gen aircraft. If we consider that currently Japan has the following fighter aircraft in service (according to wiki),

F-2 – 62
F-4 – 73
F-15J – 155
F-35 – 2

The initial F-35 order was always about replacing the F-4s and a lot of the commentary on the additional F-35 order is about replacing the remaining bulk of the F-4 fleet and a portion of the F-15 fleet that isn’t as upgradable as the latter deliveries. Hence that still leaves all the F-2s and a portion of the F-15s to be replaced in that 2030-40 timeframe. If we said that combined number was approx. 150 aircraft then it is certainly big enough for a development program to happen.

Saying that, I still don’t think the hybrid F-22 is going to happen, I think it is just too costly for the value it provides, but it certainly isn’t ruled out especially if China continues to increase PLAAF/PLANAF fighter numbers with advanced jets.

bigjku · Wed Nov 28, 2018 8:33 pm

I expect the US to eventually invite Japan and the UK into their next generation fighter program. Maybe Korea as well.

estorilm · Wed Nov 28, 2018 9:49 pm

Ozair wrote:
estorilm wrote:
Sorry everyone, getting buried at work and haven't been able to reply with some of my thoughts on things - especially regarding the engine stuff.

IN OTHER NEWS - if you read between the lines here, this latest report could almost immediately shut the door on everything we're discussing in this thread (which was always a possibility, and something I questioned; "they already have the F-35 though?") - perhaps (and I see some logic behind this) it's cheaper and nearly as effective to just get more F-35s, save $$ on commonality, training, and most importantly - no additional development/procurement costs. The extra planes still allow for an increase in defensive force projection that really can't be countered by either Russia nor China, regardless of whatever 5th gens they produce.

I don’t think this has shut the door on some type of Japanese development of a 5th gen aircraft. If we consider that currently Japan has the following fighter aircraft in service (according to wiki),

F-2 – 62
F-4 – 73
F-15J – 155
F-35 – 2

The initial F-35 order was always about replacing the F-4s and a lot of the commentary on the additional F-35 order is about replacing the remaining bulk of the F-4 fleet and a portion of the F-15 fleet that isn’t as upgradable as the latter deliveries. Hence that still leaves all the F-2s and a portion of the F-15s to be replaced in that 2030-40 timeframe. If we said that combined number was approx. 150 aircraft then it is certainly big enough for a development program to happen.

Saying that, I still don’t think the hybrid F-22 is going to happen, I think it is just too costly for the value it provides, but it certainly isn’t ruled out especially if China continues to increase PLAAF/PLANAF fighter numbers with advanced jets.

Perhaps, but this news also comes as a somewhat large surprise to many - as they don't even have a fraction of their first batch yet.

They're also about to drop NINE BILLION on these things. I'd imagine that would have to quiet things down about as far as defense spending and future programs is concerned. If you push the F-15s out between your estimate - say 2035, then something would need to begin in probably 6 years or so. Who knows what the battle space and requirements will look like by then - probably a lot different than anything we discussed above though haha.

I mean if they can stack two more missiles internally in the next few years as planned, that might just do it for them. Their order is so large, the last batch won't be rolling out for quite a while - perhaps AETP and other upgrades are on the table for those.

Ozair · Wed Nov 28, 2018 10:49 pm

estorilm wrote:
Perhaps, but this news also comes as a somewhat large surprise to many - as they don't even have a fraction of their first batch yet.

It is certainly a show of faith in the platform.

estorilm wrote:
They're also about to drop NINE BILLION on these things. I'd imagine that would have to quiet things down about as far as defense spending and future programs is concerned.

Don’t forget Japan is the third largest economy in the world and at the moment spends only approx. 1% of GDP on its defence budget. There is plenty of fat in the system for increased defence spending should they desire, especially if it goes to Japanese companies.

estorilm wrote:
If you push the F-15s out between your estimate - say 2035, then something would need to begin in probably 6 years or so. Who knows what the battle space and requirements will look like by then - probably a lot different than anything we discussed above though haha.

Agree and I expect that DEW will impact aircraft designs going forward, including Japan aspirations as well as the UK and Franco-German concepts.

estorilm wrote:
I mean if they can stack two more missiles internally in the next few years as planned, that might just do it for them. Their order is so large, the last batch won't be rolling out for quite a while - perhaps AETP and other upgrades are on the table for those.

Agree, if they look to acquire the bulk of that new order, follow on F-35As to replace the F-15s, after 2025 then they will have all Blk 4 mods as well as the current engine upgrades planned, even before AETP comes along. Given there is obviously a strong preference for the Japanese FACO to manufacture the bulk of these, and have a large backlog already coming from the FACO anyway, the delivery timeframe may work in their favour for increased capability.

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