- I-210: The original version of the I-211, powered by a pair of Tumanskii RD-20, a copy of the German BMW 003, jet engines. Never went beyond the desing board given the availability of the better Lyul'ka TR-1 engines which powered the I-211.
- I-211S: The I-211 with backwards swept wings and tail. Unfortunately the blueprints we found for this one are not in good quality so we couldn't drawn it.
- UTI-212: Trainer two-seater version of the I-212.
- I-213: Apparently another version of the I-212. Further details are unknown.
- I-214: An I-212 version with the tail berbette replaced by a rearwards facing radar and even heavier forward armament. Intended as a specialized night fighter.
- I-215D: An I-215 with a by-cycle undercarriage. Built by OKB-21 order.
- I-217: Proposed version of the I-212 with two sub-variants, one with forward swept wings and backwards swept tail and another one with backwards swept wings and backwards swept tail.
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| A blueprint of a I-211S (AKA I-211C Arrow). |
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| A general diagram showing various sub-variants. |
Sources:
1. https://en.wikipedia.org/wiki/Alekseyev_I-21
2. https://en.wikipedia.org/wiki/Alekseyev_I-212
3. http://survincity.com/2012/05/transformer-alexeev-i-211-215-216-okb-21-fighter/
