Looking at the video again, but at full screen, it's a 22.5 degree/sec turn of 4 seconds for 90 degrees. I'm trying to figure out how many J-20 lengths the J-20 is from the center. Most likely, this is not a 9G turn, given that the radius looks like 5-15 J-20s, or 100 to 300 meters. I'll try to measure the video a bit more closely. So this is possibly a low-speed turn below corner speed.
Okay, so you're referring to Deino's short video, which shows the J-20 entering a vertical line from somewhere in the neighborhood of 350 to 500 knts,,, this in not necessarily done at "Full Burner", in fact, its normally done from a medium to high subsonic cruise, with throttle feed in as the energy begins to "bottom out" near the top of the vertical line..
so as you "pull to the vertical", its a rather hard pull, likely somewhere around 6 Gs or so, could be more, could be less, throttle is advanced as energy and airspeed begin to "bleed off"... at the top when the airspeed has dropped substantially, power is like fairly high in order to prevent the aircraft from further deceleration! at the top, where you see the airplane make a sharp transition from the vertical line the pilot has applied full aft stick, popping the aircraft onto its back and continuing on through in one very sharp pitch transition back to level flight in the same direction, at a much higher altitude than the initial pitch up!
This is an "airshow" maneuver that everybody does, and for reference, "Max Moga", the first Raptor Demo Pilot referred to this as his "power loop", of course the F-22 and the Flanker each has OVT, the J-20 has the "distant coupled" canards, which are quite capable of performing this "rapid pitch transition", which occurs at very low airspeed..
If you are looking for a nine G, full afterburner turn in every ones airshow routines, look for the "vapor cloud" type maneuvers, which could be a hard pull to the vertical, the "Pugachev Cobra", or even a very tight, full burner level turn..
the purpose of the J-20 performing this maneuver is to illustrate that even without OVT, the J-20 has "full pitch authority" to make very rapid pitch transitions, both very high positive, and very high negative G pitch transitions,, I would add the the Flanker and even the F-35 are able to perform similar "pitch transitions" without OVT..
so as different as all these aircraft may or may not be?? they are all extremely capable of very high G, very rapid pitch transitions, whether the limit is 9Gs or even 11 or 12Gs,,, (AF-02 has been to a documented 9.9 Gs), these maneuvers are very difficult physiologically and not terribly relevant most of the time....
