....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!