Where to visit for Aircraft enthusiasts?

Question

I am an Aircraft enthusiast and I would like to visit an Aircraft museum or factory (do a tour)  in Russia, especially for classic USSR fighter aircraft such as Sukhoi-27. My friend from Irkutsk tells me there is a Sukhoi factory in his city but doesn't know if it does tours like factories do in other countries. Also is there something similar to Air and Space Museum like in Washington DC? Any further info on this would be greatly appreciated!