J-XX Fighter Aircraft

Re: J-xx

:coffee:
PLA general Xu Guang Yu said China's fourth-generation fighters come out within five to seven years.
Xu Guang Yu also said: As far as he knew, the fourth generation of a few years ago to start, but in 10 more thrust engine development should not be a problem, the stealth aspect of the electronic and have made great progress. Finally, he said, five to seven years come out no problem.

above statement from Phoenix Satellite TV, "military intelligence Observation Room" program. my understanding is until 5 to 7 years the first prototype plane will be born, for test flying,they need 4 to 6 prototype plane, to test many different thing,like aviation technical, engine,radar,electronic system, weapon....we don't know how long the test will be past,maybe 5 to 10 years.
after this done, the 4th generation fighters service in PLAAF,but to start, usually just small amount fighters deploy operational in airforce,they need more years to produce large amount plane service in the airforce.
general Xu saying is right, but that means saying nothing,we can think this is regular official talking. or we can think China maybe get little bit develop in Jxx project,but we should not so happy,engine still is a problem for Jxx, I think.

Re: J-xx

In a major way the turbofan is the main lacking of the modern air force in China, who used almost exclusively built Russian engines till the 80's... The WS-10 gets the job done, but it has several major flaws (response time, digital operation), yet the current is a determined one and success will shortly be realized.

Re: J-xx

China also lacks a good passive mode radar warning receiver, high frequency common integrated processors with reliable fiber optics data bus (like firewire B), a reliable FADEC.

Firewire B has 800 megabytes per second, good enough for transfer 8bit data at 10bit DC balanced betamode.

Re: J-xx

dh19440113 said:

China also lacks a good passive multimode AESA radar, high frequency common integrated processors with reliable fiber optics data bus (like firewire B), a reliable digital solid state FADEC.

Firewire B has 800 megabytes per second, good enough for transfer 8bit encoding data at 10bit DC balanced betamode.

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firewire is a kind of serial link, so the speed (800megabits/s) has nothing to do with bit width. firewire chips are widely available, so not being able to produce them directly is no impediment at all.

not sure what you mean by passive AESA and solid state FADEC. I would have thought AESA implies active emissions from each array element, and no one is going to design a FADEC with vacuum tubes so it must be solid state anyway.

Re: J-xx

jonsl said:

firewire is a kind of serial link, so the speed (800megabits/s) has nothing to do with bit width. firewire chips are widely available, so not being able to produce them directly is no impediment at all.

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I am talking about 8bit/10bit data encoding standards.
Even though a firewireB databus is faster, lighter (require less cable) and use off the shelf parts we haven't seen chengdu or shengyang adopt this innovative IEEE standard in their fighter's avionics suite.
If you know why please do tell.

Re: J-xx

dh19440113 said:

I am talking about 8bit/10bit data encoding standards

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individual serial interface standards specify a word length, but since all transmissions occur 1 bit at a time, there is no physical limit to where you place your start bits and stop bits.

moving on to 8b10b was to reduce distortion by maintaining DC balance, it makes a faster bit rate possible, but converting each 8 bit word to 10 bits is actually an overhead.

Re: J-xx

jonsl said:

no one is going to design a FADEC with vacuum tubes so it must be solid state anyway.

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Full solid states electronics has no moving part, that include hard drives and any moving device that's prone to failure.

jonsl said:

moving on to 8b10b was to reduce distortion by maintaining DC balance, it makes a faster bit rate possible, but converting each 8 bit word to 10 bits is actually an overhead.

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It is more reliable, since a integrated avionics suite uses the same cable to do many jobs. 8b/10b codes cut down low frequency and timing constraint, reduce transmission error. not having to resend packet mean improving performance.

Re: J-xx

dh19440113 said:

Full solid states electronics has no moving part, that include hard drives and any moving device that's prone to failure.

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that is true, but no one is going to be storing any program code on a hard drive, you would probably use an FPGA and load it in from ROM, or a CPLD are keep the whole lot on the chip itself. but i could only relate to the coding side of it, i suspect at some point you would have to interface with the mechanics of the engine through servos, etc.

Re: J-xx

Older Chinese electronic engine control has manual overide, which doesn't satisfy the definition of solid state. Full solid state FADEC has software set limit
(precalculated aircraft limits) that cannot be overiden.

Re: J-xx

Roger604 said:

^ Well that claim from Phoenix TV show is definitely an authoritative statement. The folks on that show are very reliable. J-XX will fly by 2012. I think all those steps... small batch production, etc... can be compressed into 3 years if necessary. And I believe the PLA senses an urgent need for J-XX. I think the first J-XX squadrons will enter service in 2015. If, as previously claimed, that the J-XX will cost less than the F-35, then it can be deployed in the high hundreds and be a formidable spearhead of the PLAAF.

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Although Phoenix TV is a major satellite channel in China, it doesn't have a very good record when comes to accurately reporting PLA related news. For example, last month Phoenix TV broke out a news that PLAAF has test flied a stealth strategic bomber H-8 which later on proved to be obviously inaccurate.