J-20 5th Gen Fighter Thread IV (Closed to posting)

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Engineer

Major
I'm still quite confused about the operation of the launching mechanism.

If the launch mechanism activates with sufficient speed, the time the door is open, launch, and closes should be fast enough to mitigate an increased RCS signature.


The setup that we all believe, requires the door to open, launch mechanism comes out, closes, AND THEN, Opens, closes again, is 2 operations.

Wouldn't those 2 motions and door openings increase RCS just as much as keep the door open for a single operation?

Also, the complexity of the system increases....

I don't see the positives..

When the opponent can see you with naked eyes, any talk of RCS is meaningless. So, it doesn't hurt to extend the missiles out of the aircraft. In fact, it would be better since it would save time and the missile could achieve a lock by itself.
 

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
But I thought the argument was canards offer less aerodynamic advantages vs regular tail planes and it was only chosen to supplement less powerful engine.

It was chosen to supplement a less powerful engine because it offered an aerodynamic advantage versus regular tail planes, allowing it to meet the aerodynamic performance of its peers with a less exotic aerodynamic configuration but more powerful engines... Meaning if the same platform was equipped with equally powerful engines to a peer, then technically it should be aerodynamically superior overall.

Putting it in a very layman way.
 

kwaigonegin

Colonel
It was chosen to supplement a less powerful engine because it offered an aerodynamic advantage versus regular tail planes, allowing it to meet the aerodynamic performance of its peers with a less exotic aerodynamic configuration but more powerful engines... Meaning if the same platform was equipped with equally powerful engines to a peer, then technically it should be aerodynamically superior overall.

Putting it in a very layman way.

....I have always wondered why the US has NEVER fielded any production fighter with canards. The US is by far the most advanced nation in aircraft technologies and canards is not exactly a recent discovery. It's been around for a long time.
 

jobjed

Captain
....I have always wondered why the US has NEVER fielded any production fighter with canards. The US is by far the most advanced nation in aircraft technologies and canards is not exactly a recent discovery. It's been around for a long time.

The US also has a staunch fear of bullpup weapons for some reason. They also preferred to cling onto the unwieldy 7.62mm for their ASSAULT rifles during the cold war which condemned the British effort to introduce an intermediate cartridge; the .280 British. The US isn't known for its revolutionary concepts like stealth, jet engines or aircraft carrier all of which were patented by other nations, but it is known for being the best at what it chooses to pursue like all of the previous 3 mentioned.
 

Air Force Brat

Brigadier
Super Moderator
....I have always wondered why the US has NEVER fielded any production fighter with canards. The US is by far the most advanced nation in aircraft technologies and canards is not exactly a recent discovery. It's been around for a long time.

Dr. Song reasoned that distant coupled canards would offer more pitch authority to the J-2O, in the event that powerfull thrust vectoring engine technology did not become available in a timely manner, and also if they were available and were used, to maintain sufficient pitch authority to recover the aircraft to controlled flight in the event of engine failure in the post-stall flight regime, as a flame-out or multiple flame-outs would render a conventlionally configured aircraft unrecoverable.....

Now the US did experiment with canards and thrust vectoring on several test bed aircraft with great success, but elected to maintain the relative simplicity aerodynamically of conventional configuration, due to the availability of powerfull thrust vectoring engines, so we have or had no need to "play around" with canards, with TVC it is no sweat to push the nose of the aircraft wherever we want it, so pitch transitions in the F-22 are effortless, as are supersonic trim issues, the airplane is trimmed with the TVC rather than trim tabs deflected into the airstream...on another note, the main wing is passing through clean air, and may be trimmed to a very neutral, ie no lift enhancing devices deployed, further reducing parasite drag...so there is absolutely no advantage to the US to employ the canard, as it does increase the complexity of the FCS, and negates the need of the main wing to pass through disturbed air......

The J-20 took a different approach to aerodynamics because powerfull TVC engines remain unavailable in China and rather than rely on the Russians and their iffy and expensive engines, Dr. Song felt he could engineer his way to a superior solution, which he proceeded to do.....and he did, why I have said many, many times the J-20 is a very "smart aeroplane", reflective of an aeronautical genius, which I believe would be an appropriate term for Dr. Song.

Like Kelly Johnson at Lockheed, Dr. Song applied his genius to accomplish what others only attempted, so the J-20 and the F-22 are both very capable aircraft, which illlustrate the old farm boy engineering philosophy of,
"Go with whatcha got", a favorite saying of my Father when he expected me to repair something that we lacked parts for, in order to save a trip to town.... Brat

The Wrights used a canard on their gliders and the Wright Flyer, the Navy's copy of the J-20 does indeed use Canards, which I deplore, but they might change the way I feel.............Nah! I'm the Air Force Brat----and a child of Lockheed Aircraft!
 

MiG-29

Banned Idiot
Does the J-20's canards give it short take off ability? Anyone know what the definition of short take off is? I remember (General He?) saying that the J-20 would have "4S Capability" that is 1. Short take-off, 2. Stealth, 3. Supercruise, and 4. Super-maneuverability. However the super-maneuverability may be technically impossible without TVC.
Yes they do, they give it a shorter take off to its delta wing.

But canards are not the only solution for STOL, F-14 uses Variable geometry swing wing for example, so everything is configuration dependent.

Viggen uses canards for STOL but its canards are of lower aspect ratio and relatively bigger, more optimised for STOL and less for lower drag
 

MiG-29

Banned Idiot
....I have always wondered why the US has NEVER fielded any production fighter with canards. The US is by far the most advanced nation in aircraft technologies and canards is not exactly a recent discovery. It's been around for a long time.

They are not the only solution for the same problem, in the US they have implemented different solutions due to different requierements and different solutions to the same problem that can be solve with equally effective different ways other than canards.

For example

F-14 uses wing gloves to fix the problem of center or pressure shift at siupersonic speeds and Variable geometry for STOL or high speed.


Their disadvantage are increased weight but are equally effective

J-20 uses to do the same Canards, LERX and delta wings.

here weight is no concern, but you equally can get something similar with LERX as in F-16 and relaxed longitudinal stability.

So everything is mission dependant and requierement dependent
 
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Schumacher

Senior Member
....I have always wondered why the US has NEVER fielded any production fighter with canards. The US is by far the most advanced nation in aircraft technologies and canards is not exactly a recent discovery. It's been around for a long time.

Having researched it for a long time is quite different from mastering it. US didn't have as powerful supercomputers, design tools etc when they did those research compared to when China design J20.
In addition, even the Soviets never fully challenged US in terms of technologies during the cold war, the challenge was mainly in numbers. So there was never the need to take risks with canards.
With stuffs like J20 now pushing the US technologically, you see the likes of Boeing trying out canards again.
 
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