Well, I would love to disagree with you here as I go by Airframe on another forum, not on there much, but I like the pretty parts better, kind of like attractive members of the opposite sex, do you prefer pretty or smart, the right answer is both, but............ Well you see where I'm going, I LOVE PRETTY, and I love the old eng adage, "form follows function", but as you and Dr. Song would agree, a gorgeous airframe with a loser power plant is still stuck on the ground. On 4/08/11 pugacheve-diver translated a text of Dr. Song in post 1675, where Dr. Song states that the F-119 engine in the F-22 is "unhumanly powerfull", and then goes on to lament, "we had no decent engine, no decent materials", but hopes that by the prototype stage those concerns are answered. I really think at some point, the PLAAF should buy those 50 or so Su-35s with the upgraded engines and avionics for some right now capability as well as hands on experience working on the powerplants with OVT, and I would order 200 or so OVT powerplants, and get a team involved in developing the J-20b, with OVT. That friend is the brilliance of Dr. Song, able to tell the truth, accept it and work toward a solution, rather than berating everyone else. Has he written any thing else lately on the J-20, I would love to know what he thinks after the J bird is having a very successfull test program, this powerplant issue was forseen by Dr. Song and planned for and engineered around it to give the PLAAF a very capable aircraft, even without OVT. but...... I would like to see the J-20 with the OVT engines that Dr. Song was dreaming of, once again he was able to envision this gorgeous airplane, design it and build it. It is an engineering and performance master piece, and yes form does follow function!
F-119 is a very powerful engine, however MiG-31`s D-30F has a 15 tonnes of thrust and the MiG-31 can fly at Mach 2.3 a similar time to F-22`s supercruise time, the difference is MiG-31 does use afterburner so the MiG-31 carries lots of fuel close to 23 tonnes of fuel and weights almost 10 tonnes more than a fully loaded F-22 making it a lumbering aircraft .
On fifth generation fighters the engines are almost the core of the system, without them you can not get supercruise, you can not get STOL, niether you can get the gains in agility without increasing wing area or reducing wing loading,
You can not exploit post stall at its max flight envelop in fact most aircraft can not even enter post stall and the few they do without TVC nozzles the maneouvres are limited.
Stealth is also limited because the IR signature depends a lot on the engine signature and the RCS increases with aerodynamic controls deflection.
with this i am not saying the airframe is not important, but to get to its max potential the stealthy airframe needs a right engine.
So in few words the airframe is much less important on a fifth generation fighter than the avionics and engines.
I am sure J-20 will get the right engine and achieve all what is expected of it, no doubt the jet will achieve its full potential, but as any weapons race the point is always when, most developed countries are making stealth machines unmanned and manned and the ability to field them on the right time is what matters.
By 2020, F-22 will be an old jet and by 2025 an old concept, in fact the reason why Russia or China want to field their jets by 2018 is not because they want to show they can build stealth fighter but because the technology also is getting obsolete, in fact the Russian project PAK-DA has been on the same pressure, some russian analylists think a STEALTH Bomber concept is obsolete,while some think it might be worthed.
Dmitry Rogozin, who has responsibility for military-industrial affairs, and the Armed Force’s General Staff over the need for a new “traditional” strategic bomber.
Rogozin said on his blog last week that it would be undesirable for Russia to "go down the American route," and produce a bomber like the Northrop B-2, and repeated his earlier calls for a hypersonic air vehicle system instead of a traditional long-range bomber.
In earlier comments, Rogozin had appeared to dismiss the need for PAK-DA, saying long-range bombers would fall victim to air defense systems long before reaching their targets.
hey by the way why do you use the Russian acronym for TVC nozzless? OBT equals
отклонения вектора тяги is not better use TVC nozzles or even AVEN (Axisymmetric Vectoring Exhaust Nozzle?
