Is This China’s First Stealth Fighter? (Picture), page 10

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reply posted on 13-2-2012 @ 12:17 PM by slanteye

reply to post by anon72

The first picture shows the Shenyang 5th Gen stealth fighter J14 with its bulging engine thrusters quite further apart and the bottom pic shows the Chengdu J20.

reply posted on 13-2-2012 @ 12:35 PM by VonDoomen

reply to post by anon72

that second one looks very photoshoppy. Right around where the nose of the plane ends and the truck sitting off in the distance.

reply posted on 14-2-2012 @ 10:40 PM by aaa2500

I am not entirely convinced that the downplay of the F-117 tech is correct.

Remember that almost everything on the F-117 was radically different. The paint is the most obvious, but the materials of the internal and external structure were radical as well. The computersystems were a departure from the ordinary as well with non radar based targetting and a fly by wire system for an aircraft that had to be coerced into flying.

All in all, I am not convinced that there were no lessons to be learned, particularly since Chinas biggest problems lie in materials and application.

reply posted on 15-2-2012 @ 12:31 AM by Aim64C

reply to post by aaa2500

I am not entirely convinced that the downplay of the F-117 tech is correct.

There are some lessons they could learn from it - though exactly what would be pretty specific to the F-117.

However, the math and various LO principles employed in the construction of the F-117 have been in the public domain for quite some time; some dating back to the 50s, before the F-117 was constructed.

Remember that almost everything on the F-117 was radically different.

It represented a considerable departure from classic aviation engineering, sure.

The paint is the most obvious, but the materials of the internal and external structure were radical as well.

But not exclusive. Better composite materials existed, in 1990, in the civilian market, and a number of specialized paints developed for the industry were not all that different from those used on the F-117 (but focused on a different spectrum or to different temperature tolerances).

The computersystems were a departure from the ordinary as well

A graphing calculator is more sophisticated than the avionics on the F-117. That's a bit hyperbolic, as the key to Fly-By-Wire controls are ultra-fast sampling and response times; a different area of focus than a graphing calculator - but you get the drift. The computer you're using to post on these forums has enough theoretical computing power to fly the entire fleet of F-117s simultaneously (and still offer considerable contributions to your Folding At Home or Seti At Home 'guild.')

They'd learn more from your average PLC.

with non radar based targetting and a fly by wire system for an aircraft that had to be coerced into flying.

Really, there's not much they could learn, in that regard, that they didn't know, already. Sensitive electronics would have self-destructed when the pilot ejected. Flying aerodynamically unstable aircraft is unique to each airframe.

They've had FLIR systems for quite a while, at that.

All in all, I am not convinced that there were no lessons to be learned, particularly since Chinas biggest problems lie in materials and application.

Mostly in quality control. They have a #-ton of people to put to work. They would rather have fatigued human laborers performing a given task than a tireless, precise machine. They are currently running into huge employment problems because, to remain in the industry, they are having to shift to more modern methods of manufacturing (precision and machinery).

The huge problem, though, is that very little of the F-117 is applicable to aircraft like the F-35 or F-22. There would be little to no insight into the construction of such an aircraft present within the F-117. The materials have changed, considerably. The airframe has changed. The avionics have -completely- changed. And the weapons systems are on a completely different level.

Aircraft like the F-18E can be considered a "Generation 4.5" aircraft. The F-117 is more like a "Generation 4B" - a different take on the 4th generation of aircraft design.

reply posted on 15-2-2012 @ 08:39 AM by aaa2500

But not exclusive. Better composite materials existed, in 1990, in the civilian market, and a number of specialized paints developed for the industry were not all that different from those used on the F-117 (but focused on a different spectrum or to different temperature tolerances).

It's not about what's better, but what works. China was and is still far behind in materials science, so even a 30 year old technology would be worth studying.

A graphing calculator is more sophisticated than the avionics on the F-117. That's a bit hyperbolic, as the key to Fly-By-Wire controls are ultra-fast sampling and response times; a different area of focus than a graphing calculator - but you get the drift. The computer you're using to post on these forums has enough theoretical computing power to fly the entire fleet of F-117s simultaneously (and still offer considerable contributions to your Folding At Home or Seti At Home 'guild.')

They'd learn more from your average PLC.

Could you be a little more condescending, I've only worked with computers my whole life. The key to understanding radiation hardening is not Wikipedia, but to examine pieces of actual hardware, looking at routing, materials, etc.

Theory is nice, but nothing beats learning from actual hardware.

Really, there's not much they could learn, in that regard, that they didn't know, already. Sensitive electronics would have self-destructed when the pilot ejected. Flying aerodynamically unstable aircraft is unique to each airframe.

That is where I think you were wrong. Russia sold China SU-27 and SU-33 with first generation(for those aircraft) computer systems, looking at comparable US systems would be very educational for the chinese. Even if sensitive electronics had self destroyed as you claim, the chinese would have been looking at it from a systemswide viewpoint. You can learn much by looking at the physical aspects of an electronics system, how is it organized, how is it routed, dimensions and materials etc.

The huge problem, though, is that very little of the F-117 is applicable to aircraft like the F-35 or F-22. There would be little to no insight into the construction of such an aircraft present within the F-117. The materials have changed, considerably. The airframe has changed. The avionics have -completely- changed. And the weapons systems are on a completely different level.

Yes, but you are assuming that China is at par with the US, and so even the F-117 is old news. Chinese aircraft construction is based on methods and materials used in the USSR up untill the 60's. They have been building copies of soviet aircraft for 50 years, but were incapable of designing and building a civil airliner until recently and it is comparable to a 70's Boeing and has been designed with massive foreign help.

The fact that they have had access to AL-31 and RD-33 for 20 years and have been unable to design and produce an indigenous copy or derivative should tell you something.

Aircraft like the F-18E can be considered a "Generation 4.5" aircraft. The F-117 is more like a "Generation 4B" - a different take on the 4th generation of aircraft design.

But still something way beyond what China was capable of in the 90's.

edit on 15-2-2012 by aaa2500 because: (no reason given)

reply posted on 15-2-2012 @ 11:24 PM by Aim64C

reply to post by aaa2500

It's not about what's better, but what works. China was and is still far behind in materials science, so even a 30 year old technology would be worth studying.

How do I word this.... Ah:

en.wikipedia.org...

Chrysler Turbine Cars were automobiles powered by gas turbine engines that the Chrysler Corporation assembled in a small plant in Detroit, Michigan, USA in 1963, for use in the only consumer test of gas turbine-powered cars. Of the total 55 units built (5 prototypes and 50 "production" cars), most were scrapped at the end of a trial period, with only a handful remaining in museums and private collections. It was the high point of Chrysler's decades-long project to build a practical turbine-powered car.

Studying this car would yield virtually no useful information on how to build:

www.pcmag.com...

The car also features a new dual-motor, all-wheel drive system, with a motor in the front and rear of the car. This allows power to quick shift to where there is the most traction, providing "incredible road holding and traction," Musk said. Additionally, the second motor boosts torque by 50 percent, allowing the car to reach 60 miles and hour in less than five seconds.

The Chrysler Turbine Car was a special build of the era, using what was available at that time.

The Tesla Model X is an all-electric car utilizing completely different construction methods, materials, and sophisticated stabilization electronics ("power steering" is taking on a whole new meaning in the computer-assisted age of driving).

It's apples and oranges; not a linear progression.

Could you be a little more condescending

Don't encourage me.

I've only worked with computers my whole life.

You do realize how tempting this is, right? ...

The key to understanding radiation hardening is not Wikipedia, but to examine pieces of actual hardware, looking at routing, materials, etc.

Again, decades old theories behind those constructions; the current ones were developed after further analysis of previously used methods.

The "Radiation hardening" of the F-117 was to not mount a giant microwave cannon on it and to go radio silent after clearing a pre-determined waypoint.

Theory is nice, but nothing beats learning from actual hardware.

Except you can learn more about radiation-hardening your electronics from a modern digital computer than you can from the F-117. The measures taken to avoid cross-talk and prevent processor cycles from inducing hell in other areas of the computer are far more advanced than anything in the F-117.

You can learn much by looking at the physical aspects of an electronics system, how is it organized, how is it routed, dimensions and materials etc.

Yeah... but there was nothing unique about the F-117's layout.

The only thing related to what you are talking about wouldn't even be on the aircraft. The simulations and math used to derive a set of instructions for handling an inherently unstable aircraft would be of great value (regardless of the generation of aircraft, or the program in question). But that is not going to be present on the aircraft.

The fact that they have had access to AL-31 and RD-33 for 20 years and have been unable to design and produce an indigenous copy or derivative should tell you something.

It's not a matter of capability for them so much as it is a matter of policy. As I said - their employment practices are their key kicker that gets in the way of technologically advanced processes.

Nor is it an issue of understanding. They simply haven't had a need to compete in the high-tech industry that has low employee-to-product ratios.

But still something way beyond what China was capable of in the 90's.

But not anything related to the aircraft on display, now.

reply posted on 16-2-2012 @ 01:56 AM by aaa2500

So basically you are maintaining that China could not under any circumstances learn anything at all from the wreck.

Well, to each his own i guess.

reply posted on 21-2-2012 @ 10:11 AM by kilcoo316

reply to post by aaa2500

They may have obtained a baseline for comparison of some things; which has some limited use.

However, it is 99% sure that the Chinese would have already been more advanced in any and all specific areas than what they would have learned from the F-117 wreckage.

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