When the Su-21S, codenamed "Flagpole" by NATO, appeared in 1978, it surprised the West which initially thought the plane to be just another failed Flagon update experiment or a testbed for systems of the recently identified Ram-L or Ram-K aircrafts.
It turned out to be a long endurance PVO interceptor, possibly meant as an interim or low-cost alternative to these new designs, using a clearly Flagon inspired but brand-new airframe and, according to some intelligence, reusing existing systems to mitigate development risk.
The aircraft is purported to use a single uprated R-35 derived from the one already used in PVO Floggers for propulsion, also borrowing the MiG-23P's radar, albeit with a larger antenna and more powerful emitter and using R-24 and R-60 missiles (up to 4 of each for a total of 8). It has been seen using up to 3 large drop tanks to accomplish its goal of long endurance patrol in the defence of the central and eastern regions of the USSR. Going against the trend of recent PVO-only interceptors, the Su-21 has 2 internal guns, sources suggesting these to be weirdly old-fashioned NR-30 with a hundred rounds each, as well as what seems to be decoy launchers.
This surprisingly elegant design was joined in 1980 by a dual-seat version, initially thought to be a trainer, but proving to be another interceptor, the Su-21P. While the single-seater Su-21S became a not too uncommon sight on the Soviet Western frontier, the Su-21P was almost absent, being more common on the other borders, the exact operationnal reason remains unclear as these planes seem to be otherwise identical.
Recent sightings suggest that the plane might not be a PVO exclusive as what are thought to be Su-21s were spotted in AV-MF colours, but not enough is known at present.   NOTEWORTHY OBSERVATIONS - As it was started as an AI only asset for my own use, I kept the original F-15 cockpit.
- Likewise, as an AI only asset for my own use, I haven't taken the time to produce hangar and loading pics.
- I did the minimal amount of modification to the INI.
- All skins can be used on both variants if you want to switch things around.
- I have included AV-MF inspired skins in the Su-21P folder, for those that might be interested (waves at Stratos), they should be considered a not so hidden easter egg.
- PSD templates specific to this Soviet version should be released alongside.
- Read the damn READ ME for install. CREDITS Everyone at Cocas Aircraft Factory for their work on the plane, and especially Cocas for listening to my whin... errrr... suggestions and always nicely doing what I was pestering him to do (the guy is just too nice for his own good) and to Nyghtfall for giving us the templates without which I probably wouldn't have bothered to do something in a releasable form.
AmokFlo for the ejection seats.
The Trooper for the pilot reskin.
(I believe) PauloPanz for the Dark Blue Soviet numbers decals.
(I believe) Lindr2 for the R-24 and R-60.
Any error or omission is just that, feel free to correct me if I forgot or misattributed anything, everything should be under the CA Fair Use umbrella unless I messed up. Have fun and good flight  Gunrunner
     Version 1.0 - 15/05/2020
    Nyghtfall :
        Original skins and templates, he did the hard part of the job
    Cocas :
        Dual-seat LOD
        Elevator modifications
        Specular map support
        Soviet variants
    Gunrunner :
        Mostly pestering poor Cocas for changes
        Normal/Specular/Holes maps
        Minor INI changes
        Bringing parts together
        Getting the credit for other people's hard work, then profit from it somehow and maybe, tomorrow, world domination ! Muwahahahahahahahahah... cough... cough... cough...