J-20... The New Generation Fighter II
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bladerunner
Banned Idiot
No you are getting two different aspects mixed up. In my last post to Martin I was referring to the bottom section in a article posted by Kyli POst 465 and reproduced at the bottom of this post. THe bolden part is what Im suggesting martin is dismissing out of hand.
The one you are talking about was just an unsubstantiated opinion I cut and pasted from the WAB forum to illustrate another POV found on a pro western forum.
Re: J-20... The New Generation Fighter II
Anti-Stealth Sensors to Tackle Chinese and Russian LO Designs
Anti-Stealth Sensors to Tackle Chinese and Russian LO Designs
Posted by David A. Fulghum at 1/11/2011 2:13 PM CST
With first flight out of the way, the discussion about China’s new J-20 stealth prototype is switching to the aircraft’s mission (fighter or, more likely, long-range strike), sensors (strike missions would require a high-resolution long-range radar) and communications (which would demand high-speed datalinks and sophisticated integration).
Conventional radars have only one-half to one-third of the range of an active, electronically scanned array (AESA) radar. Moreover, the movement of a conventional, mechanically-scanned radar antenna provides a tell-tale glint of radio frequency (RF) reflections to enemy aircraft with advanced radars. Such reflections slash at the effectiveness of a stealth airframe. China is known to be pursuing newer radar technology.
“It's too early to tell the true status of the Chinese AESA program,” says a Washington-based intelligence official. “We've seen lots of press and airshow info on the program, but that doesn't automatically translate into a robust development or give us an accurate look at where the PRC is as far as fielding one anytime soon.
“Like the [high-performance] engine, it'll be a challenge to take the step from older radars to one designed for a 5th-Gen fighter,” he says. “Again, though, the J-20 is just the first or second -- depending on whom you believe -- prototype into a very long development program.”
A two-seat J-10 fighter acted as chase plane for the J-20 during the flight
Photographs show the J-20 flying at shallow angles of attack and with its undercarriage extended. An observer posting minute-by-minute reports of proceedings to the Global Times, apparently from the fence at Avic’s Chengdu facility, said at 12:50:08 local time (04:50:08 GMT) that the aircraft had begun moving, following a second later with “accelerating” and at 12:50:16 “flying”. The landing was reported 18 minutes later.
Two passenger aircraft, one a 737, arrived at the Chengdu facility less than an hour before the J-20’s takeoff, presumably carrying important officials. The Chengdu plant is part of the Avic combat aircraft division, Avic Defense.
“Chinese military [sources] are saying that the first test pilot for the new Chinese fighter is Liang Wanjun,” the analyst says. “He has previously test flown the J-7, J-10 and JF-17. Liang has a total of 2,300 flying hours, joined the PLAAF in 1982 and became a test pilot in 1998.
It is unclear whether the J-20 is a prototype or only a technology demonstrator. Either way, it is not the only program for an advanced combat aircraft.
The deputy chief of the air force, He Weirong, said in November 2009 that in 2017-19 China would field a “fourth-generation” fighter, which in China means an aircraft of the F-22’s technology level. He was not referring to the J-20, however, because a month later a prominent news report in English quoted the People’s Liberation Army Air Force (PLAAF) as saying that the 2017-19 fighter would be an improved J-10. It is possible that the 2017-19 fighter is a supercruise version of the J-10 since the Chinese navy has expressed the need for an aircraft that can maintain fuel-efficient, long-distance, supersonic flight, a necessity for keeping enemy forces away from the coast of China.
The Chengdu J-20 design has struck most analysts and observers as familiar and somewhat different that the Lockheed-Martin F-22 and F-35 as well as the Sukhoi T-50.
“The J-20 is reminiscent of the Russian MiG 1.42 both in terms of planform, and also with regard to the rear fuselage configuration,” says Douglas Barrie, senior fellow for military aerospace at London’s International Institute for Strategic Studies. “The most obvious difference is the greater forward fuselage shaping as the basis for low observable characteristics, along with the different engine intake configuration. The MiG program was cancelled by the Russian government around 1997.”
Others note that the planform also has a resemblance to Sweden’s SAAB Viggen.
Another issue that will continue to surround all stealth designs is how long will current stealth designs offer invulnerability as air defenses adopt even larger and more powerful AESA radars. From the early days of AESA development, a key goal was to build a radar that can detect a very small object like a cruise missile at a distance great enough to target and shoot it down or a larger object like a fighter with a very low observable treatment.
Airborne detection of stealth aircraft may have already been accomplished in a series of tests done at Edwards AFB, Calif. in the second half of 2009. Those with insight into the research say Lockheed Martin’s CATbird avionics testbed –a 737 that carries the F-35 joint strike fighter’s entire avionics system -- engaged a mixed force of F-22s and F-15s and was able to target the F-22s.
"The F-35 mission systems suite is the most sophisticated and powerful avionics package of any fighter in the world," said Dan Crowley, Lockheed Martin executive vice president and F-35 program general manager at the time of the tests.
His clue about the fighter’s anti-stealth capability is in a reference to confronting new, sophisticated, foreign aircraft.
“The F-35's avionics include on-board sensors that will enable pilots to strike fixed or moving ground targets in high-threat environments, day or night, in any weather, while simultaneously targeting and eliminating advanced airborne threats,” Crowley said.
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EDIATH
Junior Member
I think it is pretty clear that there are two J-20 prototypes out there, each one using different engines so the PLAAF can see which performs better. For example
and a couple of more showing the same:
Could those engines in fact be the AL-31F also used on the J-11 and the WS-10A used on the J-11B?
Yet the nozzle is perhaps the most changeable (may I say the least complex too?) part on a jet engine, would it be premature to determine the actual engine based on nozzle shape? For example, AL-31FP is quite the same engine as AL-31F apart from its TVC nozzle.
Maggern
Junior Member
About the engine...There's four points:
1. There have been rumours about two prototypes, with two different engines.
2. There haven't been a picture with two different prototypes in the same image, and "!both" use the number "2001".
3. There have been two different pictures about two prototypes using two types of engine,
4. The weird-kind of engine was used during the test-flight.
A couple of points:
1. We discussed earlier the chance of the PLA changing the engines of one prototype. If this happened, it happened incredibly fast and without anyone taking any kind of notice of it. Kinda incredible.
2. Just as with the space walk, the Chinese might want to have one indigenous platform and one imported, proven one. They might want one imported, proven one, to do the basic stuff that has little relevance to the engine, and then do one flight with the indigenous engine to have one try with a completely indigenous design to show something off to the big shots.
3. It seems noone has been able to confirm the kind of engine used during the test flight, though few has been able to claim it was an AL-31F. Most likely it was indigenous of some kind.
PS: I doubt is was WS-15, but I guess it was some kind of stop-gap Ws-10 used to push forward the indigenous engine infrastructure (as tphuang have indicated), though not fully optimizes, as we have heard from maya that the WS-15 is still far from completed. Also, I kind of agree with some of the senior members that the 117S is doubtful to be used, as the Russians would bask in the glory of this sale and use it for every penny it's worth. We'll have to see.
So far I see it like this: WS-15 is not completed and far from any practical use in a prototype. 117S is so cutting-edge a sale would be adverstized in every page imaginable. WS-10 itself is guised to be too little powerful to fully allow the J-20 to fully utilize its potential. I'm practical enough to allow some kind of WS-10-version to be used so as to satsify the level of indigenization used here while still using a version that is not completely functional.
PPS: Thanks, all moderators (and esp. Popeye). This thread was going the wrong way. I appreciate the work you put into making it come back full circle and....you know...
1. There have been rumours about two prototypes, with two different engines.
2. There haven't been a picture with two different prototypes in the same image, and "!both" use the number "2001".
3. There have been two different pictures about two prototypes using two types of engine,
4. The weird-kind of engine was used during the test-flight.
A couple of points:
1. We discussed earlier the chance of the PLA changing the engines of one prototype. If this happened, it happened incredibly fast and without anyone taking any kind of notice of it. Kinda incredible.
2. Just as with the space walk, the Chinese might want to have one indigenous platform and one imported, proven one. They might want one imported, proven one, to do the basic stuff that has little relevance to the engine, and then do one flight with the indigenous engine to have one try with a completely indigenous design to show something off to the big shots.
3. It seems noone has been able to confirm the kind of engine used during the test flight, though few has been able to claim it was an AL-31F. Most likely it was indigenous of some kind.
PS: I doubt is was WS-15, but I guess it was some kind of stop-gap Ws-10 used to push forward the indigenous engine infrastructure (as tphuang have indicated), though not fully optimizes, as we have heard from maya that the WS-15 is still far from completed. Also, I kind of agree with some of the senior members that the 117S is doubtful to be used, as the Russians would bask in the glory of this sale and use it for every penny it's worth. We'll have to see.
So far I see it like this: WS-15 is not completed and far from any practical use in a prototype. 117S is so cutting-edge a sale would be adverstized in every page imaginable. WS-10 itself is guised to be too little powerful to fully allow the J-20 to fully utilize its potential. I'm practical enough to allow some kind of WS-10-version to be used so as to satsify the level of indigenization used here while still using a version that is not completely functional.
PPS: Thanks, all moderators (and esp. Popeye). This thread was going the wrong way. I appreciate the work you put into making it come back full circle and....you know...
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歼20是军工业内隐患最多的战斗机
身为中国总装备部飞机项目总验收官的章兆衷少将，他在中国航空军工界内被誉为：火眼金睛。他参与验收了解放军空军的歼7，歼8，歼10，歼11，枭龙等著名的空优战斗机，其验收量高达4000架。但是，他却对目前网络热炒中的歼20战斗机不屑一顾，以下是他对美国《哨兵报》记者专访时，一篇发言：
章兆衷少将：一架战斗机的先进与否，不是依靠他的外观来得到的，而是真实的实力表现。歼20目前估计一架需要2.5亿美金造价甚至更多，即便今后的我国军方倾其所有来制造。那么最近 10年空军的军费预算中也就是能采购30架服役。这些数量战斗机，在一定程度上可以以其先进的技术，来弥补其数量不足。但是，在第2次世界大战末期，纳粹德国制造了世界上首批喷气战斗机，Me262。它对于盟军任何一种战斗机，都是具有绝对地速度，航程，机动等三大致命优势。但是，70架的Me262战斗机面对的却是当时盟军动用的4000架P40等老式战斗机。因此，它最终还是被淹没在盟军战机的海洋中。而歼20同样未必能给中国空军带来质的改变。
歼20现阶段有很多缺陷无疑在实际作战中是完全致命的。首先，由于它坐舱设计有问题，导致飞行员没有后视视角能力。但是在目前的战场上，如果没有这个能力，如何能面对俄罗斯印度等国先进的具有可以回旋发射的苏30战斗机呢？
其次，歼20在先决射击上有重大失误。歼20由于技术积累不足，在与对手直接面对期间，其在同等发现概率时间下，必须晚于对手1.0-2.0秒的时间，才能完全完成开仓－下拉－发射这个连贯动作。因歼20的导弹都是安装在弹仓内部。但是对手的导弹却是挂在机翼下部。而电子坑余度的幅度差仅有百万分之1，因此，这等于在1秒到2秒内，歼20处于非隐形状态坐等对手开火射击，如果对手同样具有3代战斗机的快速自动火控能力下，那么不需要1秒，歼20的飞行员就会看到对方导弹进入了自己的机舱。
另外，根据成飞提交的阶段研究报告，歼20目前机械性能极差，预计每次最多能安全运行1.7小时就得维护，而且维护时间很长，要24小时。一旦这个问题无法解决，这将导致歼20战斗定位出现很大问题。对付二流空军的国家歼20属于大炮打蚊子，费效比远不如歼10和歼11。对付空军一流的军事大国，耐力差的它连长时间值班的能力都没有。鉴于歼20预计中的高昂造价，它能起的作用实在与其价格不成比例。
歼 20在成飞的报告书上，自称将达到超音速巡航飞行，其实这是一个十分含糊的概念。超音速巡航飞行，通常会被人们误认为是：从基地起飞就是一直超音速巡航，一直到战役结束。但是，实际上歼20提出的超音速巡航，仅仅是类似前苏联那种铝制米格25M的瞬间超音速加速巡航飞行理念。歼20只能以1.5倍音速最大巡航时间 7.5分钟。这对于在战区内的歼20起不到根本的逃避作用。至今为止，全世界只有一种飞机可以真的实现远距离超音速巡航飞行那就是美军的F22猛禽。只有它们可以采用3倍音速加速飞行，2倍音速航行2个小时。这是世界纪录，没有任何一架战斗机可以匹敌它。
歼20预计将从2020年12月起开始装备中国空军。预计到2030年，军方可能才有足够的钱完成购买30架飞机的计划。 从技术上来讲，军方研制购买歼20的策略也有非常大的风险。歼10的设计制造是用了二十多年才完成，军方购买飞机时，一手交钱，一手交货，对歼10的性能了解非常清楚；但空军未来在购买歼20时，对歼20的性能不是非常了解，歼20很可能会改来改去长期无法定型生产。
最后再来说它被网络热炒得十分耀眼的隐身。歼20的隐身技术在实际质地上，与美国B2轰炸机以及F22战斗机相差甚远。甚至很可能不如早期的F117。成飞提交的隐身涂料验收时不过关，未达到性能，暂时只能靠涂很厚的不合格涂料来勉强达标。这样做的话很容易造成涂料脱落，无法应付真正的战场，简单的说就是它根本不能隐身。在进
行开引擎机体实验时，引擎开加力后，歼20机身温度会急升，导致红外信号特征大涨，其机身整体热效反映将接近一架波音767，那么即便是最老式远程预警雷达都可以对其识别。一旦失去了隐身外衣以后，暴露在阳光下面的就是歼20那身臃肿的身躯，接下来我估计对手的飞行员，会开始思考从那里下第一口，去吃掉这头价格高昂的胖鸟了。为了解决这个难题，成飞又不得不给它多设计了一层蒙皮，由于隐身涂料抹得特别厚，万一飞行中有剥落，被吸入进气道，后果就不堪设想了，所以这是一个很严重的安全隐患。
在我看来，这种设计思路落后的战斗机根本达不到五代机标准，要对付拥有足够数量四代战斗机的对手，是很难有太大效果的。
附歼20的其他缺陷：
1，歼20预计造价超过了F22，这还不是最大的麻烦。它最大的缺陷就是对机械维护要求极高，一架飞机需要几个高级工程维修人员照顾，所需要的特殊螺丝特制抹布都价格惊人。就算PLAAF能买得起，也养不起太多歼20。
2，制造歼20内引擎叶片合金必须使用特殊的重稀土材料，该材料受制于国际市场。我国稀土储存量很大，但稀土分轻重，我国只有轻稀土出产，重稀土大多产自北美大陆。
3，歼20的机体结构强度也存在很大问题，而且飞控要求很高，飞行员在高G状态时很容易忽然昏迷，造成飞机坠甚至落空中解体。未来的歼20很可能无法在恶劣天气下使用。
4，歼20机体大耗油量也大，因为国内设计水平不高导致机内燃油不足，预期歼20服役后会有腿短的毛病，航程会惨不忍睹，甚至有可能只有歼6水平。而且因为内油不足，即使歼20能达到超音速巡航，它的超巡时间也大大缩水了。具体多少，很难说，悲观估计可能只有7分多钟。
5，为歼20开发的WS15发动机性能预测并不好，导致歼20气动设计过于保守，空中超机动性能很可能无法达标。
6，歼20设计弹仓太小，不能装对海对舰的大型导弹，只好开发小直径导弹来用。如果能用隐身远攻大型导弹，还勉强可实现全程隐身攻击，在对方防区外发射隐身巡航弹，打完立刻调头返航。现在要飞到离目标较近的位置才能陆攻，在高水平防御体系面前，无法保证全身而退。
7，歼20内部挂点太少，只有6个(4+2)，俄罗斯的T50有8个内部挂点（6+2），而设计最优秀的F22猛禽的内部挂点更多更好。
J-20 is the most problematic aircraft ever built.
production cost for J-20 is higher than F-22,engine tend to overhead making her vulnerable to IR detection and her supercruise capapbility report to also limited.
the aircraft is not as agile as F-22.
J-20 plan to enter service in 2020.
it admission some of RAM material are substandard.
despite her large size.her internal storage is in fact slighly smaller than t-50.only 6 internal weapon phylon .compare 8 to T-50
Engineer
Major
Considering China is fielding the biggest type of airborne AESA radar out there, I would say China is actually ahead in stealth-detecting capabilities.
NO I did not, he claims you do not have the RCS or AESA data for J20, which is indeed true. Regarding LM, did they say at what ranges the F35 can detect F22 or provide any specific numbers? Even current Russian radars are claimed to be able to detect F22 at a close enough range.
(Wait until you get to engage one) speech.
I was waiting for some on eto bring this up. This showed up as a baiting post on CD before. The author pieced together an article criticising the F-22(allegedly written by an engineer at Northrop Grumman) and some personal speculations.
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