So what is the chance we will see a J-11D with TVC? Nil?
Given the investment into J-20 I think it is more likely we will see upgrades of existing airframes for air force fighters. With only J-16 and maybe J-15 Flankers remaining in production.
It’s a far more complex and difficult job to retrofit TVC to twin engines fighters than single engined ones, well it is if you want to use TVC to its full potential with differential directional thrust.
On top of the already formidable FCS law re-writes, a far more challenging potential issue would be structural. Especially on a plane like your flanker with widely spaced engines.
On fighters, very kg is precious, so the odds of the baseline flanker airframe having the structural tolerances built in to handle differential directional thrust from TVC is slim to none. That may be a major contributing factor to why early Russian TVC testbed flankers did not feature differential deflection capabilities.
Indeed, one of the main reasons for the PLAAF to press ahead with its Su35 purchase may well be a desire to see what kind of structural reinforcements the Russians needed to put in to allow it handle differential thrust TVC.
The Su35 purchase is also another reason why I would rate it less likely that the Chinese would develop a J11/16 flanker TVC testbed. Why spending millions of dollars and years of research to re-invent the wheel when you already have the solutions from decades of Russian testing and refinements in the form of the Su35?
Indeed, the structural refinements on the Su35 compared to the baseline J11 and enhanced J16s would be if especial interest to the Chinese in helping to cut down on the time and efforts needed to adapt the J20 for TVC, if that was not already built into the design from the offset.
But even if structural strength to handle full TVC was already built in, looking at the evolution of the Flanker line may still yield useful info on how to better refine the existing design.
