Hello!
Of course this topic is about Polikarpov's projects. Not about arrests, not about Yakovlev or something else. But I think I must answer to colleagues Arjen and Wurger. Excuse me if something is wrong.
Do you really think so? OK, let’s try to count…
Antonov, Arkhangelsky, Bakshaev, Bedunkovich, Belyaev, Beriev, Bisnovat, Bolkhovitinov, Borovkov/Florov, Cheranovsky, Chetverikov, Dubrovin, Gribovsky, Grushin, Ilyushin, Kamov, Kocherigin, Kozlov, Kurbala, Lavochkin/Gorbunov/Gudkov, Mikoyan/Gurevich, Moskalyov, Nikitin, Pashinin, Polikarpov, Rafaelyanz, Rentel, Samsonov, Scherbakov, Silvansky, Shavrov, Shevchenko, Sukhoi, Tairov, Tsybin, Yakovlev, Yatsenko, Yermolaev. Probably it isn’t the complete list. I think I didn’t remember them all.
All these people were Chief Designers at late ‘30s – early ‘40s in the USSR. You can see here the “great names” (marked out) and not so great names; of course there were more and less talented, more and less experienced, more and less successful among them. But they all projected and built aircraft of their own designs. And nobody of them was imprisoned.
Who WAS imprisoned? If we’ll count those who designed aircraft of their own – Tupolev of course, then Bartini, Chizhevsky, Kalinin, Nieman. Petlyakov and Myasischev weren’t in this category: they were only Tupolev’s subordinates before being arrested. You can say it sounds sacrilegious, but it’s still a fact – their arrest turned a chance to realize themselves in designing their own projects! I don’t mention Korolyov, because at the time of his arrest he already wasn’t aircraft designer at all: he worked on rockets in the RNII.
Were ALL they victims of spurious charges? Actually, we don’t know!.. Of course you can say: “How can you doubt?! Any doubts here are sacrilegious!” But we need FACTS, not emotions – don’t we? Even if somebody is a technical genius, it doesn’t mean he cannot be involved in anything bad. Somehow the original documents of Tupolev’s case aren’t published until now. We only can read in literature that “accusations were typical, like “damage-making” and espionage”. But why can’t we see true documents? If he was totally innocent, what‘s the reason for keeping them secret?
(Of course I know that Tupolev was rehabilitated in 1955. But this could be a political act as well).
Returning to Polikarpov - his arrest in 1929 is totally different story, which took place in totally different era. And we must understand one thing: that time Polikarpov wasn’t yet the great man we know today! Before 1929 he designed just a few aircraft, and only ONE of them – the I-3 was relatively successful! (Also the R-5, but it just finished the tests. I don’t count the R-1, as it was only DH-9 copy and nothing more). The first Polikarpov’s own design – IL-400 fighter prototype had its CG at 52 % of MAC. It crashed on August 15, 1923 during first flight attempt, and it was true wonder that test pilot K. Artseulov survived. The 2I-N1 two-seat fighter destroyed in the air on March 31, 1926, during maximum speed test flight, killing test pilot V. Filippov and a timekeeper. Even the first prototype of what became the legendary U-2 (Po-2), arisen in 1927, was almost unflyable – until its wings were completely redesigned…
Today, knowing the whole Polikarpov’s career, we regard all this only mistakes caused by lack of experience. But imagine how could it be interpreted by the contemporaries! They really could consider Polikarpov a “damage-maker”, it surely didn’t look like a nonsense!
Who are they? I know Konstantin Kalinin only, and I'm sorry but I can’t regard him an innocent victim... Try to imagine: the K-7, a giant, extremely expensive aircraft, destroys in the air killing 16 people onboard… Of course I don’t think he intentionally made that mistake in his calculations. But I also can understand those who deemed he must bear responsibility for this. Who else, if not the designer?.. Designing aircraft is not a joke, it’s very serious...
Is it so strange – to be a patriot of your Motherland? Is it necessary to become a traitor for everybody who met some difficult days in his life?
Oh my god! How is Yakovlev connected with this?.. He left Vice Minister chair on July 8, 1946, of his own free will. All the aircraft you mentioned arose later! For example, Su-9 was first flown on November 13, 1946; Su-11 on May 28, 1947; Alexeev’s I-211 in late autumn 1947 – only couple of months before MiG-15! The I-212 was built already in summer 1948! Do you really think that these straight-wing designs had prospects in the MiG-15 era?
And what does it mean, to your mind? As for me, it means only one thing: that the bald, fat man with a shoe in his hand ;D , known as great lover of maize and rockets, pulled him away like many others whom he considered “Stalin’s guys”…
Don't forget, this man nearly destroyed Soviet military aviation at all!
And you say, Yakovlev’s creativity faded away?.. Who designed Yak-25, the first successful all-weather interceptor in the USSR? And the first and only Soviet VTOLs? And the excellent Yak-40 regional jet, probably the world’s progenitor of this popular class?... 
But Soviet aviation is my primary interest. So I think that rather you are mistaken, than I am .
