China Military Watch

[vina]

note how the MBAs knuckle dragged the riff raff technology guys who thought they had a lot to protect. when these tech guys are laid off later, the MBAs will get fat bonuses for cutting costs, raising shareholder value via their china JV and give speeches in ivy league schools.

Ah.. All you guys are just jealous. Who told you not to get a YumBeeYea ?. . You could have done all the "re-engineering" and "shareholder value creating" and the rest of it!

[Arya Sumantra]

Austinji - that is a lame excuse. Either you have stealth or you don't have stealth

+1 . Even between Day and Night the boundaries are blurred by a gradual increase in darkness but the answer to whether you will need an artificial light source to see something is a definite YES or NO.

Same way, whether the enemy is able to see your plane is a definite YES or NO regardless of where your plane lies on Visible-Stealthier-Stealthiest spectrum.

I think it would boil down to balance between Stealth and Performance and the need to have right amount of both can just vary between individual countries capability and requirements spelt out by their airforces

Austin sir, that’s why you should NOT optimize between stealth and aerodynamic performance but rather make your plane as stealth as possible. That makes sure that answer to whether enemy can see you is turned to a NO from a YES.
But the fossil minds at the head of RuAF seem so obsessed with flying at 2+ mach that they chose to compromise some stealth for aerodynamics. And their requirements become our shortcomings.

The main point of Stealth is: Bankability that you won’t be seen. It makes more sense to be slow but invisible rather than sporting semi-stealth with a curved rear belly and exposed engines. IMVVHO, Pak-Fa’s stealth is like the hiding of an ostrich by burying its head.

And with expensive regular maintenance when you take so much pains to maintain the stealth of your frame you would rather carry more pyrotechnics for your enemy than a minimalist baggage.
Still all is not lost. Making FGFA complete stealth(covered flattened rear) and more payload will give HAL probably more than 25% workshare that it seeks.

Maximum Stealth and Maximum Payload should be the idea for a heavy fighter like FGFA while somewhat acceptable stealth and medium payload for a workhorse fighter like AMCA. Makes sense because russkies are more advanced than us in aviation while we are still learning and need to pick up fast and mass produce. But the scenario is exactly opposite- Import & heavy FGFA from more advanced country to be compromised stealth and local and medium AMCA expected to be COMPLETE stealth. !!! Priorities all reversed. Soft on imports and demanding on domestic learners repeating itself.

JMT

[Cosmo_R]

@Singha^^^:"To make the GE deal happen, GE Chief Executive Jeffrey Immelt made an extraordinary concession, agreeing to fold into the venture all of GE's existing world-wide business in nonmilitary avionics."

Five years ago, Immelt projected $15bn/year in India revenues by 2015 and $10 bn by 2010. Today, the number is ~$2bn. He has publicly expressed frustration at the 'obstacles' to growth in India and in China.

While one can argue that what GE is actually giving up is a market lagging business unit (the old if we are not one of top 3 then out), then why did they not do something similar (JV) in India? For example, the F-136 engine which the Pentagon does not want but is still a great engine could have been produced along lines similar to the AVIC JV. One frustration is the 26% cap on defence FDI but could the GoI not have made the same strategic calculus that the PRC are making?

Note also, in the GM/SAIC deal, it's a classic Hezbollah defence. Get GM in between China and India so the Indians have to fight both if we want to impose anti-dumping.

[nits]

India's Joint Defence HQ Orders Study On J-20

Two days before retiring from service, Air Marshal SC Mukul, the chief of India's Integrated Defence Staff (IDS) has instructed a Group Captain-rank officer at HQ IDS to prepare a report on the recently revealed Chinese stealth fighter prototype. The report will be India's official assessment of what, by all accounts, is a Chinese fifth generation platform.

The study will, of course, rely mostly on open source material -- photographs, graphics, unofficial assessments -- on the J-20, officer entrusted with authoring the report will also take inputs from the IAF Directorate of Operations, the Directorate of Naval Aviation, the advanced projects and AMCA divisions of the Aeronautical Development Agency (ADA), the National Aerospace Laboratory (NAL), the Aircraft Research & Design Centre at HAL, apart from the R&AW. The report will be provided to the Indian Air Force and the office of the National Security Advisor.

[nits]

How It Works: China's Antiship Ballistic Missile

The most alarming weapon China is developing to deny the U.S. Navy access to the East and South China seas is the antiship ballistic missile—the first such missile able to change course to hit a moving aircraft carrier. Mounted on a mobile launch vehicle, an ASBM would rise in two stages, reach space and then use fins to maneuver at hypersonic speeds on its way back down. The warhead then glides along a level path to permit synthetic aperture radar, which processes multiple radar pulses to form a single picture to target the carrier. Finally, the warhead’s infrared seeker locates a carrier’s signature and closes in for the kill.

[ShauryaT]

Thanks Nits. I was speculating along these lines of a SAR controlled and terminal IR to guide this thing. If China has indeed perfected this technique. They do seem to have the assets in place by way of long range DF 21 and enough SAR based satellites in place for regional coverage.

How effective is SAR for targeting?

[Austin]

Austin sir, that’s why you should NOT optimize between stealth and aerodynamic performance but rather make your plane as stealth as possible. That makes sure that answer to whether enemy can see you is turned to a NO from a YES.
But the fossil minds at the head of RuAF seem so obsessed with flying at 2+ mach that they chose to compromise some stealth for aerodynamics. And their requirements become our shortcomings

I dont think one should invest more on one aspect say stealth over other say aerodynamic performance , if you just end up with a bird which is just stealth but compromises its flying qualities, kinemetics or agility then it is just a question of detecting the bird , who is to say stealth will not get detected by radars, EO/IR or passive detection now or in the future.

A balanced approach is always desirable , as far as PAK-FA goes i think they did the right thing by making the next level in aerodynamic performance over flanker which was sukhoi ace while keeping LO in mind , who is to say improvements in structures,materials ,RAM will not make stealth better without compromising performance , if there is any consolation then the chief designer of PAK-FA claimed that stealth of the fighter will not be inferior to F-22.

Recently Lockheed claimed that structure/materials used in JSF were more advanced then F-22 where stealth does not get degraded even in the event of some structural damage to the aircraft.

[Victor]

That pic posted by zlin on the previous page captioned “best picture so far” is indeed strange. Aircraft with all-moving tailplanes do use opposite control to use them as spoilers or brakes but in all cases, the deflection is even and equal on both tailplanes in order to preserve line of flight or ground roll. The tails in this picture have widely different angles and this is odd. The plane is shown turning around on the tarmac so it could be a ground steering mechanism connected to one tail (the left one).

[manum]

I think its about playing with your strength and putting your best foot forward...US has coined the term stealth and they are masters in it, no doubt, they have achieved the avionics, materials, engine and stealth shapes to gain to a level that then can depend on it totally...and now after F-22, there will be something next soon to reveal, mostly a most advance UCAV ...

russia on the other hand has always made the most maneuverable aircrafts, so they'll bank upon it, even if they try to adopt stealth, as per US established definition...but I don't know, when there are no dogfight scenario in case of BVR and radar as capable as much as f22 (as they say)...the game rule has to re-written, or one has to be absolute, PAKFA is still kinda old school, may be Indian venture will change the last baggage to an extent...

China, what they have to enter into the game...thats what is the question to ask, or they don't have any other option except to enter into absolute stealth....but then I would have liked them to bank upon UCAV...than stealth fighter...they could have also offered it to pukes, to change the game altogether and rush us...and others...

slowly it might become all about stealth and electronic warfare, in that case mathematical parametric computation might take over old aerodynamic studies...this is an unknown arena India still is to enter...China has, to an extent, and it'll slowly get in position to establish a doctrine by assessing what it has achieved so far, or might achieve. stealth is very Utopian term...and in case of real capability and propaganda it has great use...so is the case of ucav. because once you are aware of a bit of situation, you want to be completely aware of it....and once you enter into such a zone of utopian tactics to defy all contextual advantages by regional capabilities....you start growing the Idea and stealth will become a habit...

so once we know PRC has tried his arena already, we worry about next coming years and what still is to come....and it'll play in our mind, till we don't tread the path ourselves and know...

[Jamie Boscardin]

Cross posting from another thread, as this is the right forum:
In the world of defense there are only a handful of defense companies who based on their governments perogative decide to sell or not to sell to another country.
USSR and now Russia have always stood by India both militarily and politically for a long long time. And due respect to all folks, Russia is/has/will be a genuine friend of ours.

We ourselves cant help our own friends, if we don't have the means to help, and this is even highly applicable to complex country to country relationship. And there are no free lunches anywhere.
As long as the oil and gas prices remain high, Russia doesn't need anyone's money.

NRoa ji,
Its a truth that partnership/friendship is between equals, not when one is the provider and the other the require always. Russia/USSR has always been the supplier and we the users, modifiers..In this kind of a situation, you take what you get, or leave it...
Though may not be applicable but there is a saying, beggars cant be choosers. The point that Russians came to IAF long ago to take feedback on T-50, take notes and offer the platform does show that their is a level of friendship in play here. There of-course will be issues, but that doesn't mean that someone has to be put in tenterhooks. And I would assume that if India was a supplier and equiper to another nation, there would be a attitude issue among us also, cant help it, its human nature.

Singha ji,
If I assume that what you are saying is true (China is superior in every aspect than Russia), then would love to see your answers to some of the questions:
1. How come they have a huge espionage network, whose primary task is to get every and any kind of data relating to almost everything including military designs, which is used to reverse engineer stuff?
2. How come the Chinese slaves (Pakis), want to change the avionics of their fighters with western avionics, though they come standard with "technologically" superior Chinese stuff?
3. In the same context, how come the Pakis are buying western equipment, when they can get all those superior platforms from China in a fraction of cost Or even free if they can keep India busy?
4. How come superior China is getting ready for another big import of defense hardware from
Russia including the S-400 etc, SU-34 etc
5. How come they don't have a single engine to fly their birds in-spite throwing the entire nations top resources in getting it done.
6. The anti-carrier ballistic missile, the 5th gen fighter are all 10 yrs away and we are cranked up on it..

I can keep on adding to this list endlessly...

If China is good at something, that is at mass producing products at the cheapest possible price (by squeezing the life out of their fellow citizens)..obviously when you are developing RC planes, they dont become fighter planes just by increasing their size...so lets not make an issue out of nothing!!!!

[Austin]

China’s Military Modernization: the Russian Factor
Moscow Defense Brief by Mikhail Barabanov

[Indranil]

Close up of the gear doors:

It is really a little weird. Such a low undercarriage will take substantial FOD damage from the front wheel!

I would really like to see a close up pic of the plane. I want to see what kind of rivets are exposed (if it is exposed in first place).

I believe the canard tips align with the tips of the rudder. and would create vortices at high AoA not only for boundary layer separation but also yaw authority.

The canards really spoil the look of this plane and would surely be very detrimental to both front and side FCS. But I think it is good functionally.

Barring the canards and the ventral fins, the plane looks good. I like the high wing body blending. It is quite smooth.

[Jamie Boscardin]

China’s Military Modernization: the Russian Factor
Moscow Defense Brief by Mikhail Barabanov

Austinji,

Thanks for the article.
This is exactly what I was trying to say.
The Chinese government is actually planting the stories of their great technological might all across the globe so that they can hide the actual story behind. This is the same they do with their own citizens, who are fed information which the government wants them to read (I do sympathize with them when most of them settle abroad after knowing that the chinese world is different from the world outside)..

[Indranil]

This plane at least looks like having the space for rearward facing radar.

[Austin]

China's J-20 Stealth Fighter In Taxi Tests
By Bill Sweetman

[kvraghav]

This plane sports DSI intakes.Doesnt it mean that theoretically this plane max speed is 1.8 mach?

[DavidD]

That really makes no sense at all. There is no fine line on the observability axis dividing between stealth and non stealth. A platform is only stealthier or less stealthy and there are always compromises between stealth and maneuverability.

The only exception is the F-22. Therefore comparisons with the F-22 are pointless because that aircraft is currently rated has holding the standard for stealth and maneuverability combined. It sets a very high bar that no one has reached. Yet. Every other plane has to offer "excuses" as to why the stealth achieved does not match up to the F-22 but even after that compromise matching the maneuverability is a problem.

Nope, the F-22, like every plane in existence that's interested in both stealth and maneuverability, has compromises between the two qualities. That it's the most stealthy(B-2's stealthier tho) and maneuverable aircraft does not mean that it could not have been even stealthier or even more maneuverable had it sacrificed a bit more of one or another. For example, a sphere is THE perfect shape for LO, but the F-22 doesn't look like a basketball now does it? After all, a basketball-shaped aircraft probably won't meet the maneuverability requirements.

[DavidD]

Thanks Nits. I was speculating along these lines of a SAR controlled and terminal IR to guide this thing. If China has indeed perfected this technique. They do seem to have the assets in place by way of long range DF 21 and enough SAR based satellites in place for regional coverage.

How effective is SAR for targeting?

That seems a bit far fetched, the vehicle's reentry speed would heat it up so much that terminal IR guidance should be fairly useless.

[DavidD]

That pic posted by zlin on the previous page captioned “best picture so far” is indeed strange. Aircraft with all-moving tailplanes do use opposite control to use them as spoilers or brakes but in all cases, the deflection is even and equal on both tailplanes in order to preserve line of flight or ground roll. The tails in this picture have widely different angles and this is odd. The plane is shown turning around on the tarmac so it could be a ground steering mechanism connected to one tail (the left one).

But what if you want yaw control AND airbraking at the same time? Then you'd need them to be turned differentially. In fact, you NEED yaw control at all times, so if the only yaw control surfaces are to be used as airbrakes, then they would have to be able to turn differentially.

[DavidD]

OK, BRF really needs a multi-quote function! I suppose in the meantime I'll just try to do it myself

Close up of the gear doors:

It is really a little weird. Such a low undercarriage will take substantial FOD damage from the front wheel!

I would really like to see a close up pic of the plane. I want to see what kind of rivets are exposed (if it is exposed in first place).

I believe the canard tips align with the tips of the rudder. and would create vortices at high AoA not only for boundary layer separation but also yaw authority.

The canards really spoil the look of this plane and would surely be very detrimental to both front and side FCS. But I think it is good functionally.

Barring the canards and the ventral fins, the plane looks good. I like the high wing body blending. It is quite smooth.

The landing gear doors are on the left, the maintenance doors are on the right, they're separate. Only the maintenance doors have very low clearance, and they wouldn't be open during flight.

China’s Military Modernization: the Russian Factor
Moscow Defense Brief by Mikhail Barabanov

Austinji,

Thanks for the article.
This is exactly what I was trying to say.
The Chinese government is actually planting the stories of their great technological might all across the globe so that they can hide the actual story behind. This is the same they do with their own citizens, who are fed information which the government wants them to read (I do sympathize with them when most of them settle abroad after knowing that the chinese world is different from the world outside)..

There's a saying among the Chinese expats that goes something like "when we were in China, all we do is curse the CCP, and when we're outside of China, all we do is defend the CCP." What the expats find out after they leave China is that the CCP portrays China as heaven while the westerners portray China as hell(I'm exaggerating a bit on both accounts), but the truth is somewhere in between.

This plane sports DSI intakes.Doesnt it mean that theoretically this plane max speed is 1.8 mach?

There's some talk that the DSI is adjustable, we probably have to wait a long time to get confirmation of that though.

[Don]

http://www.defensenews.com/story.php?i= ... =AIR&s=TOP

Photos of Chinese 5th-Generation Fighter Revealed
By WENDELL MINNICK
Published: 30 Dec 2010 08:02 TAIPEI - China's fifth-generation stealth fighter program took a noticeable step forward this week when the first high-resolution photographs appeared on Chinese non-governmental websites of a prototype of the Chengdu J-20 fighter being built for the People's Liberation Army Air Force (PLAAF)

In the photos, the J-20 appears to be conducting a high-speed taxi test. There have been suggestions the photographs are fake, including questions over the unusually large Chinese red star painted on the tail. PLAAF red star insignias are normally smaller with parallel adjacent red bands.

In the past, due largely to grainy photos taken by cell phones, the existence of the J-20 was treated with some skepticism by many observers.

However, the newest photos are "the real deal," said Richard Fisher, an Asia military affairs analyst at the Washington-based International Assessment and Strategy Center.

The photos reveal the J-20 has a canard-delta twin-engine configuration, diverter-less supersonic intakes, and a shaped nose consistent with the use of an active electronically scanned array (AESA) radar.

The J-20 design is similar to the Lockheed Martin F-22 Raptor and the Sukhoi T-50 fighters. Sources indicate the twin-engine J-20 prototype could be using the Russian-built Saturn 117S (AL-41F1A) engine, the same being used in the T-50 and Su-35 prototypes. China has expressed interest in procuring large quantities of the Saturn 117S from Russia and rumors at the recent Zhuhai Airshow in China indicate a J-20 prototype had been outfitted with the 117S.

There is also the possibility the prototype is being outfitted with the Chinese-built Shenyang WS-10 or WS-15 engine.

"At first glance this fighter has the potential to be competitive with the F-22 and to be an efficient F-35 killer," Fisher said. Fisher is the author of the new book, "China's Military Modernization."

The release of the J-20 photos follows comments made last week by U.S. Pacific Commander Robert Willard in the Japanese media that China had reached the "initial operational capability" of its first anti-ship ballistic missile (ASBM), the Dong Feng 21D. The DF-21D has been dubbed the "aircraft carrier killer" in China, a reference to China's overall anti-access and area denial (A2/AD) strategy.

China's ability to undermine two critical pillars of U.S. deterrence in Asia, with the ASBM and now with the advent of its first 5th generation fighter, "points to a real crisis in U.S. political-military leadership" in Asia, Fisher said

[ShauryaT]

^^ How reliable is this guy, before I buy his book. I am open to recommendations to read book(s) and/or sites to understand the most likely Chinese defense capabilities. Please recommend, before I go on a wild goose choose.
Thanks.

[Don]

http://www.spacewar.com/reports/China_s ... r_999.html

China steps up anti-carrier missile tests: US commander


by Staff Writers
Tokyo (AFP) Dec 28, 2010
China is stepping up efforts to deploy a "carrier-killer" missile system, the commander of the US Pacific Command has said in an interview with a Japanese newspaper, published Tuesday.
"The anti-ship ballistic missile system in China has undergone extensive testing," Admiral Robert Willard told the Asahi Shimbun in Honolulu, according to a transcript of the interview on its website.

Willard said China appeared to have achieved "initial operational capability" but it would take "several more years" before fully deploying the system.

US military analysts have warned China is developing a new version of its Dongfeng 21 missile that could pierce the defences of even the most sturdy US naval vessels and has a range far beyond Chinese waters.

Washington has expressed rising concern over China's military intentions following a string of double-digit increases in Chinese military spending and the rapid modernisation of its armed forces.

In the interview, Willard also said China aims to become a global military power by extending its influence beyond its regional waters.

"They are focused presently on what they term their near seas -- the Bohai, Yellow Sea, South China Sea, East China Sea," Willard said.

"I think they have an interest in being able to influence beyond that point, and they have aspirations to eventually become a global military," he said. "In the capabilities that we're seeing develop, that is fairly obvious."

Referring to tensions on the Korean peninsula, Willard warned that North Korea is ready to take another provocative step and called on China, Pyongyang's sole major ally, to play its role in defusing the situation.

"I think, for now, we're past this particular crisis, but we have no doubt, given North Korea's history, that a next provocation is readied," Willard told the daily.

"It's a matter of assessing how it might be deterred or how the North Koreans might be dissuaded from exercising the next provocation," he said.

"We think the US-Republic of Korea (South Korea) alliance is part of that deterrence effort," he said. "We think the international community and China in particular are another part of it."

Tensions have been high following the North's shelling of a South Korean border island, which killed four people, including two civilians. The South's forces are on alert for any fresh attacks.

[shiv]

Close up of the gear doors:

Nice image. So it is some sort of access door. The serrated edges, as per the theory I have read should give a far lower radar signal than a straight edge. An extension of that - from reading here and there is the need to maintain the perfect fit that the serrated doors are supposed to maintain with the serrated edge of the hatch.

Anyone who cleans the kitchen knife and the cutting board in the kitchen knows that dirt collects up in the grooves between the teeth of the knife that takes more effort to clean than the board. This of course is true of a door that sits near the undercarriage of an aircraft. The added issue is that a serrated edge may be twice or 3 times as long as a straight edge. Knocks and bumps of day to day use eventually erode the quality of stealth - at least as per the criticisms levelled against the F-22. Presumably these doors will fit into their place far better than the fit seen of the JF-17 (FC-1).

[shiv]

http://www.defensenews.com/story.php?i= ... =AIR&s=TOP
Photos of Chinese 5th-Generation Fighter Revealed
By WENDELL MINNICK
a shaped nose consistent with the use of an active electronically scanned array (AESA) radar.

Correct. As Einstein points out above the shape of the nose determines whether an AESA can be accommodated inside or not. For example the shape of the nose of the F/A-18 is incompatible with an AESA, unlike the F-22 and F-35 and J-20.

One of the things that non technical reader morons (such as most of you imbeciles on this board) do not understand is the importance of shapes and appearances. Despite being bald and having a paunch I put on a bikini at the beach yesterday and was mobbed by young men who saw my bikini an mistook me for a beautiful model.

[amit]

China's J-20 Stealth Fighter In Taxi Tests
By Bill Sweetman

Sweetman's article has this very interesting point:

The way in which the J-20 was unveiled also reflects China’s use and control of information technology to support national interests. The test airfield is located in the city of Chengdu and is not secure, with many public viewing points. Photography is technically forbidden, but reports suggest that patrols have been permitting the use of cell phone cameras. From Dec. 25‑29, these images were placed on Chinese Internet discussion boards, and after an early intervention by censors—which served to draw attention to the activity—they appeared with steadily increasing quality. Substantial international attention was thereby achieved without any official disclosures.

The Chinese take their Sun Tzu very seriously. The speculation machine will now get to work and build a sooper dooper plane out of this J20 even before it takes to the air.

We've already had some folks here, hinting that this plane is even better than F22. And we've had "anal-ysts" writing that it's "certainly" better than the PAK-FA, without knowing what, radar it will carry or what engines will power it. All based on some pictures released by the PLA of a taxi trial. (BTW was any video released of the plane actually moving?)

Jai Hu!

[amit]

Despite being bald and having a paunch I put on a bikini at the beach yesterday and was mobbed by young men who saw my bikini an mistook me for a beautiful model.

Doc don't be too harsh. The bikini was your stealth skin and so you looked more comely (and small in the middle) on the radars of these young men.

That's how stealth works rite?

[Singha]

>on the radars of these young men.

[songfeihong]

Now military fans in China are bashing each other with another rumor: There are other two models of G5 birds being produced in Shenyang. The logic is that the one leaked is exclusively used for air superiority purpose as counter part of F22. One of the other two models is a multipurpose fighter and the other is for navy carrier. The unreleased two models will have normal layout as F22 or T50 without canard. Twin engines configuration. At least one of these two,most likely the multipurpose one, will have it maid flight sometime next year.

[kvraghav]

@DavidD
Adjustable DSI?I thought DSI was meant to eliminate moving parts and the flow dynamics restricted the Mach numbers greater than 1.8 .Please suggest some links to elaborate on adjustable DSI.

[dinesha]

China readying for military conflict from all directions, says minister
http://timesofindia.indiatimes.com/worl ... z19exXWeQo

China's defence minister BEIJING: China's defence minister has put aside diplomatic tact and said the country's military will prepare itself for "military conflict in every strategic direction" in the next five years. The military will speed up modernization and development of equipment, he said.

"We may be living in peaceful times, but we can never forget war, never send the horses south or put the bayonets and guns away," defence minister Liang Guanglie said in an interview published in state-backed newspapers. China's pace and scale of military modernization and construction of military related infrastructure has caused alarm among neighbours like India, South Korea and Japan.

http://www.telegraph.co.uk/news/worldne ... ction.html

"The modernisation of the Chinese military cannot depend on others, and cannot be bought," Mr Liang added, "In the next five years, our economy and society will develop faster, boosting comprehensive national power. We will take the opportunity and speed up modernisation of the military."

[disha]

Now military fans in China are bashing each other with another rumor: There are other two models of G5 birds being produced in Shenyang. The logic is that the one leaked is exclusively used for air superiority purpose as counter part of F22. One of the other two models is a multipurpose fighter and the other is for navy carrier. The unreleased two models will have normal layout as F22 or T50 without canard. Twin engines configuration. At least one of these two,most likely the multipurpose one, will have it maid flight sometime next year.

Excellent point. That is what I thought too, that there is already J20 for Ground Strike and another for Air Superiority and a slight change to make a naval version just like Joint Strike Fighter.

Now do you have a photo of one landing on an Air carrier deck? In the middle of a Ocean? It will prove our point!

[neerajb]

@DavidD
Adjustable DSI?I thought DSI was meant to eliminate moving parts and the flow dynamics restricted the Mach numbers greater than 1.8 .Please suggest some links to elaborate on adjustable DSI.

There are simpler/fixed intakes on supersonic aircrafts too like MiG-27 which uses splitter plate. DSI is not meant for simplicity but lower RCS by avoiding splitter plate which is a good reflector of RF. Fixed DSI is stealthy analogus of normal fixed intake sporting splitter but with a performance penalty (?) as with a fixed geometry intake. Adjustable DSI should bring the advantages of variable geometry with stealth.

Cheers....

[Indranil]

The landing gear doors are on the left, the maintenance doors are on the right, they're separate. Only the maintenance doors have very low clearance, and they wouldn't be open during flight.

That makes sense ... What doesn't make sense is why was this access door open even during the "taxi" trials?

[Kanson]

China's defence minister has put aside diplomatic tact and said the country's military will prepare itself for "military conflict in every strategic direction" in the next five years.

It seems, actions and statements of China brought back memories of the rise of Nazi Germany and WWII.

Just as Obama went for appeasement in the form G2, Anglo-France alliance went for appeasement with Nazi Germany. Just as there is economic depression, there was economic depression, which forced the allies for the appeasement. Just as Chinese leaders are praised, fascist leaders were praised.

Just like Chinese, Hilter took that as the arrival of German Aryans.

If China become Nazi Germany in toto, it is the question of when, wondering who will be Poland, France, Britain and Russia. Of course we can safely guess who will be Austria and without batting an eyelid we can say Taiwan will be Czechoslovakia. In this scheme of things Iran will be Italy.

[Kanson]

Now military fans in China are bashing each other with another rumor: There are other two models of G5 birds being produced in Shenyang. The logic is that the one leaked is exclusively used for air superiority purpose as counter part of F22. One of the other two models is a multipurpose fighter and the other is for navy carrier. The unreleased two models will have normal layout as F22 or T50 without canard. Twin engines configuration. At least one of these two,most likely the multipurpose one, will have it maid flight sometime next year.

Hmm....are you talking about J-16/J-19? Heard one more stealth design with conventional layout without canards.
Are they not dropped for J-20? Any pics? description? More than rumour is there any information to confirm its presence.

One of the other two models is a multipurpose fighter and the other is for navy carrier.

Is it J-13?

[Kanson]

DF-21 Delta: Some Early Thoughts

The so-called DF-21D is much in the news recently, mostly because it hasn’t shown up yet. It is reputed to be the anti-ship version of China’s short-range workhorse, the DF-21. (China uses some version or other of the DF-21 for short-range ballistic missiles, anti-satellite weapons, and ballistic missile defense.) I thought I’d start the analytical discussion of this virtual missile by making some simple calculations about what sort of transverse accelerations its terminal phase guidance and control systems are going to need.

The first point to make is that (unless it is using a nuclear warhead) it is going to need terminal guidance to fine tune the warhead’s trajectory as it reenters the Eearth’s atmosphere. This is true regardless of how well China needs the position of the target carrier—the only target worthwhile shooting at. Consider the scenario China’s military must assume: as soon as a DF-21D is launched (and hence detected by US early warning satellites) every carrier anywhere near the missile takes off at maximum speed in some random direction. If the DF-21D is launched at maximum range (again something China’s military planners would need to assume), each ship could be some 13 km away from where it was a the time of launch. The DF-21D would have to correct for that change sometime during its flight. The most logical place to correct for those changes are sometime after the end of the boost phase since the target carriers—the only targets worth shooting at—can zig and zag at anytime.

Thrusters vs. Fins

The answer is, of course, both if you got ‘em. But each mechanism for changing the warhead’s trajectory will require its own target tracking system. Ideally, you want to make changes in trajectory as early as possible since the longer you have to accelerate to the new trajectory, the lower the magnitude of the required trajectory (and, among other things, the more control you have over the final result). If the DF-21D warhead uses infrared sensors—putting aside the question of whether or not China has the required technology for a moment—then it will have to use them during the coast phase of its trajectory. Otherwise, the heat of reentry will blind the sensor if it tries to use them after it reenters the atmosphere, say something like 50 km altitude to pick a round number.

At these altitudes, the warhead cannot use aerodynamic surfaces to change its direction. So it will need thrusters—little rocket engines—to change its direction. Of course, China does has plenty of experience with fine tuning trajectories with small thrusters from its satellite insertion operations. The most likely method China might use for such a platform is a “bus” that holds the warhead while little thrusters change its position. What sort of thrust would they need? Assuming the warhead makes its corrections as the warhead passes below 100 km altitude in order to minimize the time the target has for changing its direction (again, I’m pulling these numbers out of thin air) it would have enough umph to change the velocity of the warhead/bus combination by 0.6 km/s. (This is calculated by assuming the thrusters need to change the direction of the warhead by 13 km in the 22 seconds the warhead has between when it passes 50 km—the minimum altitude I assume it can still use IR sensors). That, in turn, requires a little more than three G’s (three times the acceleration of gravity). That is probably about the requirements needed for China’s ASAT weapon tested in January 2007. So that seems possible.

If the warhead shuts down its IR sensor as it passes 50 km altitude, it is about 22 seconds before impact. It is too much to hope that the carrier can change its direction or even its speed in those few remaining seconds so the we can expect; the George H. W. Bush displaces 100,000 tons! That means the warhead can “safely” extrapolate the position the carrier will be 22 seconds after its tracker shuts down. During those 22 seconds, the Bush could travel 370 meters, which is about the length of the Bush (333 meters) but five times the beam of the Bush (77 meters). How likely a hit will be will depend on two things: how accurately the tracking system can determine the position and velocity and how finely it can tune its acceleration to match the desired trajectory.

If, for some reason, China relies solely on aerodynamic surfaces for maneuvering then it will have to wait until it gets even closer to the Earth’s surface for really effective control. Let’s assume it needs to wait until its 30 km above the Earth’s surface before the warhead’s fins “bite.” Of course, it could have stored the needed maneuvers from an IR sensor that shut down several seconds before it started maneuvering. On the other hand, it could use a radar to track the target since 50 km is well within the range of most radars mounted on fighter jets today.

At 30 km, the warhead is 13 seconds before impact. If it has to do all its maneuvering to cover the 13 km assumed miss distance, than it will need to change its velocity by nearly 1 km/s. That, in turn, will need an acceleration of 7 G’s. That is certainly possible achieve using only aerodynamic surfaces (SCUD warheads probably had nearly 10 Gs of transverse acceleration as they corkscrewed during their reentry during the first Gulf War). However, it needs to be very finely tuned and that seems the hardest point. No matter what, it would require considerable testing to develop.

Is a DF-21 Anti-Ship Missile Possible?

These rather simple calculations have shown that both types of guidance and control for an anti-ship ballistic missile are possible. But both would be pushing China’s technology considerably. For instance, China can most likely build mid-infrared detectors for military space applications. These might be used for their missile defense interceptor, even though they are barely applicable for anti-satellite weapons. Could they be used for an anti-ship application? Possibly. They could certainly see through most clouds so cloud cover is not an issue. But it would take more thought than I have given it to know that it could discriminate between a ship and the ocean. Radars, which with their limited range would require aerodynamic maneuvering, seem even more problematic because of the need to control large accelerations.

So, while I cannot rule out the DF-21D on first principles, it would need a sustained test and evaluation program no matter what technology it used. I, for one, am unaware of China undertaking such an extensive test program.


George William Herbert

Don’t assume carriers can’t maneuver much in 22 seconds; most iron bombs dropped in WW 2 had fall times not much longer than that and missed by wide margins as carriers and other ships changed direction rapidly. Knowing when the key 22 sec period is might be hard for the defender, though.

Midcourse guidance updates might be passive, rather than active, as well. A lot of antiship missiles take a datalink update that way. As long as whatever provided the initial target position indication can provide an update halfway through missile flight or later, you can get a lot of the target position uncertainty reduced.

There are terminally guided submunitions listed in media descriptions, but not how many or how big. They list destroying aircraft, the control tower, and “penetration” but no particular details that I know of.

It’s important to take this with somewhat of a grain of salt. Various Russian antiship missiles were described as the end of carriers in the 80s; SM-2 improvements and F-14s with Phoenix missiles to engage missile carriers out at the edge of engagement range made those less of a threat.

DF-21D warheads are SM-3 engageable exoatmosphericaly and SM-2 engageable on terminal descent. You can see them coming 1000+ km away on radar due to the trajectory, and the launch warnings from satellites should be robust. They’re a threat – but it’s not clear if it’s really that much worse than prior threats.

[kvraghav]

There are simpler/fixed intakes on supersonic aircrafts too like MiG-27 which uses splitter plate. DSI is not meant for simplicity but lower RCS by avoiding splitter plate which is a good reflector of RF. Fixed DSI is stealthy analogus of normal fixed intake sporting splitter but with a performance penalty (?) as with a fixed geometry intake. Adjustable DSI should bring the advantages of variable geometry with stealth.

I have seen the Mig-27 ones and i know the advantages.I just wanted to know what is the adjustable DSI intakes,because DSI intakes are usually fixed and they stand for divert less.So does the adjustable intakes means that there will changes to the position of the BUMP in front of the intakes, Something similar to the mirage-2000 intakes?

[neerajb]

Actually what I wanted to point out was your assertion that DSI's (Diverterless (aka Splitter plate less) Supersonic Intake) main purpose is simplicity. Simplicity wise DSI or fixed intakes are similar, the main objective of DSI is to reudce RCS by removing the diverter from a conventional intake.

I heard about 'adustable DSI' for the first time in this thread only and assuming that the contour and position of the 'bump' will be changed dynamically to provide compression as well as removal of boundary layer. Check out the youtube video of F-111 intake posted by me in this thread, I think it should be something similar to it. JMT.

Cheers....

[Singha]

even the Mirage2000 has a moveable cone thing + splitter plate. other a/c have some structures inside to constrict the airway at higher speed (mig29/25/F15).......fixed intake with no such cone or structure is allegedly limited to mach1.8 - like Tejas.