Zavod 39 (TsKB-) designations

[igor-mich]

Also, I've just added to the list:

• the TsKB-31, mentioned on the Czech website Ruslet as being a projected development of the Kocherigin LR (TsKB-1): https://ruslet.webnode.cz/technika/ruska-technika/letecka-technika/kocerigin-s-a/lr-ckb-1/
• the TsKB-37, mentioned in the book Fighting Cockpits, by Donald Nijboer, as being the first Ilyushin Il-2: https://books.google.fr/books?id=ON0uDAAAQBAJ
• the TsKB-50, mentioned on a German website as a 1939 prototype of the Il-2: http://www.sepsy.de/rus-il2.htm

Of course, all of these will have to be confirmed from other sources.

The prototype of the TsKB-50 was not the TsKB-55 (BSH-2) - the first flight on October 2, 1939.The IL-2 had a prototype of the TsKB-55, TSKB-55P and TSKB-57.