Moderators: richierich, ua900, PanAm_DC10, hOMSaR
Quoting mats01776 (Reply 3): March 15, 2016: ”Smoke test" for afterburners, one side at a time? |
Quoting Spudh (Reply 7): Traditional area ruling reduced cross sections, thereby reducing internal volume |
Quoting angad84 (Reply 8): Oh and incidentally, keeping everything internal in a VLO/LO design actually saves you some drag versus an equivalent loadout mounted out in the airstream on a 4th-gen fighter. I'm not sure if there's any data floating around, but I would wager that subsonic drag for a large range of payload/fuel/range combinations would probably be lower on fifth-gen types. It's only when you start talking about lots of firepower (A2A or A2G) over relatively short ranges that 4th-gen birds would likely come out ahead, because of their larger carrying capacity overall (more hardpoints). |
Quoting tjh8402 (Reply 11): even if it isn't carry as much ordinance as the 4th gens |
Quoting angad84 (Reply 8): I'm not sure if there's any data floating around, but I would wager that subsonic drag for a large range of payload/fuel/range combinations would probably be lower on fifth-gen types. |
Quoting angad84 (Reply 12): so when you find yourself with a fleet full of F-35s and needing lots of missile or bomb carrying capacity |
Quoting angad84 (Reply 12): Exactly and this is why stuff like Boeing's 2040C F-15 Eagle exists. An F-35 will probably be less draggy overall and have longer legs than a 4th-gen bird with equivalent *weaponry*, but most 4th gen types can comfortably outshoot an F-35, so when you find yourself with a fleet full of F-35s and needing lots of missile or bomb carrying capacity, you's suddenly strapping things onto the *outside* of an F-35 and it's a very, very awful story for all involved. Physics can be a bitch sometimes. Cheers A |
Quoting KiwiRob (Reply 19): |
Quoting KiwiRob (Reply 19): So why are the Japanese building this demonstrator, will it turn into a product they will eventually build? |
Japan will delay a decision to develop a new advanced fighter jet, four sources said, as military planners struggle to settle on a design and officials splash out on new U.S. equipment such as ballistic missile interceptors and F-35 stealth planes.
Faced with a growing military threat from North Korea and increased activity by Chinese air force jets over the East China Sea, Japan is under pressure to improve its defenses on two fronts.
Any delay to the new fighter, known as the F-3, will raise a question mark over the future of what could be one of the world’s most lucrative upcoming military contracts, estimated at more than $40 billion to develop and deploy.
A decision after the first half of 2018 would be too late for it to be included as a core program in a new five-year defense equipment plan beginning April 2019 that Japan will reveal at the end of next year.
“The direction is for the F-3 decision to be put back,” said one the sources who have knowledge of the discussion.
Ozair wrote:Looks like any work on a new Japanese fighter jet is now going to be delayed.
Japan will delay a decision to develop a new advanced fighter jet, four sources said, as military planners struggle to settle on a design and officials splash out on new U.S. equipment such as ballistic missile interceptors and F-35 stealth planes.
Faced with a growing military threat from North Korea and increased activity by Chinese air force jets over the East China Sea, Japan is under pressure to improve its defenses on two fronts.
Any delay to the new fighter, known as the F-3, will raise a question mark over the future of what could be one of the world’s most lucrative upcoming military contracts, estimated at more than $40 billion to develop and deploy.
A decision after the first half of 2018 would be too late for it to be included as a core program in a new five-year defense equipment plan beginning April 2019 that Japan will reveal at the end of next year.
“The direction is for the F-3 decision to be put back,” said one the sources who have knowledge of the discussion.
http://www.reuters.com/article/us-japan ... DD0D4?il=0
Funding priorities and a tight timeframe are the major concerns. If this occurs it also presents difficulties for the agreement signed earlier this year between the UK and Japan to investigate co-development.
LightningZ71 wrote:You have to imagine that any further development would have to be in cooperation with South Korea with their aspirations for a stealth aircraft as well. You also need buyers that will likely never threaten either country for geographic reasons. We know that several Middle Eastern countries want stealth fighters, Saudi and UAE in particular. Why not involve a four way partnership where the deep pockets of those emirates help support the development of a joint aircraft between S.K. and JPN? That way, everyone gets what they want, and no one is dependent on US and european designs and support.
LightningZ71 wrote:You have to imagine that any further development would have to be in cooperation with South Korea with their aspirations for a stealth aircraft as well. You also need buyers that will likely never threaten either country for geographic reasons. We know that several Middle Eastern countries want stealth fighters, Saudi and UAE in particular. Why not involve a four way partnership where the deep pockets of those emirates help support the development of a joint aircraft between S.K. and JPN? That way, everyone gets what they want, and no one is dependent on US and european designs and support.
LightningZ71 wrote:While I fully support the idea of the historic enmity between South Korea and Japan, it seems over the last few years, and especially since the suspected hydrogen bomb detonation in North Korea, that, at least at higher levels, South Korea and Japan have begun to see things as more of a cooperative struggle with respect to China and North Korea. Public opinion may still be less than favorable between the two, and especially in South Korea, but, it's not as heated or overt as it used to be. If I may be so bold, it appears that the younger generations of both countries have moved beyond the past to a great degree, especially considering how popular it seems that the J-POP and K-POP artists are in each other's countries lately.
ThePointblank wrote:There are still many Koreans outraged by the Japanese for the suffering their people had endured when Korea was a colony of Japan, and the lack of refusal by Japan to even acknowledge the issue.
From Wikipedia
In January 2005, the South Korean government disclosed 1,200 pages of diplomatic documents that recorded the proceeding of the treaty. The documents, kept secret for 40 years, recorded that the Japanese government actually proposed to the South Korean government to directly compensate individual victims but it was the South Korean government which insisted that it would handle individual compensation to its citizens and then received the whole amount of grants on behalf of the victims.[9][10][11]
The South Korean government demanded a total of 364 million dollars in compensation for the 1.03 million Koreans conscripted into the workforce and the military during the colonial period,[12] at a rate of 200 dollars per survivor, 1,650 dollars per death and 2,000 dollars per injured person.[13] South Korea agreed to demand no further compensation, either at the government or individual level, after receiving $800 million in grants and soft loans from Japan as compensation for its 1910–45 colonial rule in the treaty.[11]
However, the South Korean government used most of the grants for economic development,[14] failing to provide adequate compensation to victims by paying only 300,000 won per death in compensating victims of forced labor between 1975 and 1977.[13] Instead, the government spent most of the money establishing social infrastructures, founding POSCO, building Gyeongbu Expressway and the Soyang Dam with the technology transfer from Japanese companies.[15] This investment was named Miracle on the Han River in South Korea.
As the result of this revelation[according to whom?], there have been growing calls for the South Korean government to compensate the victims. A survey conducted shortly after the disclosure showed that more than 70 percent of South Koreans believe the South Korean government should bear responsibility to pay for those victims. The South Korean government announced that it will establish a team to deal with the appeals for compensation, although "It has been the government's position that compensation for losses during the Japanese occupation has already been settled".[12]
July 03, 2005 23:18
In every country there are crimes that uniquely reflect its society. National Intelligence Service director-designate Kim Seung-kyu, in a lecture he gave late in May when he was justice minister, said: "The three representative crimes of our country are perjury, libel and fraud." In simple comparison, not taking into account population ratio, South Korea saw 16 times as many perjury cases in 2003 than Japan, 39 times as many libel cases and 26 times as many instances of fraud. That is extraordinarily high given Japan's population is three times our own.
The common denominator of the three crimes is lying; in short, we live in a country of liars. The prosecution devotes 70 percent of its work to handling the three crimes, the former justice minister said. And because suspects lie so much, the indictment rate in fraud cases is 19.5 percent, in perjury 29 percent and in libel 43.1 percent. "Internationally, too, there is a perception that South Korea's representative crime is fraud," Kim said, adding that recent major scandals show how rampant lying is in this country.
Meanwhile, the X-2 technology demonstrator that Japan built to help prepare the way for the fighter program has exceeded goals in tests, a program official says. Manufacturer MHI first flew the X-2 in April 2016 before handing it over to ATLA, which put it to work in test flights beginning the following November. At first, 50 test flights were planned—but data from many was so good that later excursions could be skipped, says the official, speaking at the seminar. The data was accumulated in only 34 flights, each about 1 hr. in duration.
Radar signature was one area of outperformance, the official says, declining to elaborate. The IHI XF5 engines also did better than expected under the adverse conditions of high angles of attack.
LightningZ71 wrote:You have to imagine that any further development would have to be in cooperation with South Korea with their aspirations for a stealth aircraft as well. You also need buyers that will likely never threaten either country for geographic reasons.
The differential between the gross domestic product (GDP) of Korea and Japan was 17 times in 1980, 11.4 times in 1009[sic], 5.4 times in 2010, and 4 times last year. The GDPs of Korea and Japan last year were US$1.221 trillion and US$4.901 trillion, respectively.
estorilm wrote:I know this got dragged out of the archives already, however I just can't help but comment on the design of this thing.
What exactly is the purpose of it? A demonstrator should attempt to tackle the most difficult aspects of a successful 5th gen stealth fighter, correct? AKA internal weapons stores and dealing with both IR and radar signatures of the thrust vectoring / nozzles? It doesn't seem like they've done either. I mean I appreciate the chevron-pattern deflectors at the rear, but the exposed brackets, braces, and other misc hardware seems like a HUGE hit to any hope of a decent RCS, not to mention it would appear to be fairly inefficient aerodynamically (large gaps from exhaust to deflectors, etc). Likewise, it has a massive F-16-style bubble canopy on it with (what appears to be) zero coatings or other RCS. Also, there doesn't appear to be any actual RAM or coatings on the aircraft - another huge developmental hurdle that will need to be figured out.
I hate to take something away from them (it is flying, after all) but aren't the items I mentioned (in addition to extremely complicated avionics and LO radar / sensor systems) about 90% of what makes development of 5th gen fighters so complicated and expensive? It seems like they skipped over all the hard stuff, focused on the other 10%, and said "look, we can do it too!"
keesje wrote:estorilm wrote:I know this got dragged out of the archives already, however I just can't help but comment on the design of this thing.
What exactly is the purpose of it? A demonstrator should attempt to tackle the most difficult aspects of a successful 5th gen stealth fighter, correct? AKA internal weapons stores and dealing with both IR and radar signatures of the thrust vectoring / nozzles? It doesn't seem like they've done either. I mean I appreciate the chevron-pattern deflectors at the rear, but the exposed brackets, braces, and other misc hardware seems like a HUGE hit to any hope of a decent RCS, not to mention it would appear to be fairly inefficient aerodynamically (large gaps from exhaust to deflectors, etc). Likewise, it has a massive F-16-style bubble canopy on it with (what appears to be) zero coatings or other RCS. Also, there doesn't appear to be any actual RAM or coatings on the aircraft - another huge developmental hurdle that will need to be figured out.
I hate to take something away from them (it is flying, after all) but aren't the items I mentioned (in addition to extremely complicated avionics and LO radar / sensor systems) about 90% of what makes development of 5th gen fighters so complicated and expensive? It seems like they skipped over all the hard stuff, focused on the other 10%, and said "look, we can do it too!"
I wouldn't pay to much attention to the details, this is more proof of concept.
It's a prototype, most of it will be fine tuned / adjusted for a final design. Like in the past.
Oh I totally get that, I guess my point was just that they only seem to be proving the easier concepts, not the ones they should probably be looking at or which will give them the most issues. I can respect that they know more about aeronautical engineering than I ever will, but it was just more of an observation I suppose.
estorilm wrote:keesje wrote:estorilm wrote:I know this got dragged out of the archives already, however I just can't help but comment on the design of this thing.
What exactly is the purpose of it? A demonstrator should attempt to tackle the most difficult aspects of a successful 5th gen stealth fighter, correct? AKA internal weapons stores and dealing with both IR and radar signatures of the thrust vectoring / nozzles? It doesn't seem like they've done either. I mean I appreciate the chevron-pattern deflectors at the rear, but the exposed brackets, braces, and other misc hardware seems like a HUGE hit to any hope of a decent RCS, not to mention it would appear to be fairly inefficient aerodynamically (large gaps from exhaust to deflectors, etc). Likewise, it has a massive F-16-style bubble canopy on it with (what appears to be) zero coatings or other RCS. Also, there doesn't appear to be any actual RAM or coatings on the aircraft - another huge developmental hurdle that will need to be figured out.
I hate to take something away from them (it is flying, after all) but aren't the items I mentioned (in addition to extremely complicated avionics and LO radar / sensor systems) about 90% of what makes development of 5th gen fighters so complicated and expensive? It seems like they skipped over all the hard stuff, focused on the other 10%, and said "look, we can do it too!"
I wouldn't pay to much attention to the details, this is more proof of concept.
It's a prototype, most of it will be fine tuned / adjusted for a final design. Like in the past.
estorilm wrote:"Oh I totally get that, I guess my point was just that they only seem to be proving the easier concepts, not the ones they should probably be looking at or which will give them the most issues. I can respect that they know more about aeronautical engineering than I ever will, but it was just more of an observation I suppose. "