YAKs are great fun planes, but under EU legislation they are a pain in the butt. There are only a few registers, where it does make sense to operate them. I have two friends, one with a YAK-50 and another with a -54, both are telling dramatic stories with maintenance and airworthiness paperwork. There where times when Lithuanian register was the way to go for them, then some changes to San Marino register, but whatever you do - it is a complicated matter to get permit to fly. And if something goes wrong with papers, you are dead in the water - the friends -50 is now grounded for more than three years due to paperworks issues (and from what I hear this is not uncommon for Yaks).

Wow that sounds scary! Stuff like this is why I slightly lean towards the Extras....

Chickenhouse you nailed it there..

I have a SU-29 grounded because of this.
EASA has made it possible to register such planes under a C of A.

The amount of paperwork needed is so huge, and the maintenance facilities (Can't publish names here) EASA approved both paperwork and maintenance so bad, that in the end you don't get what you pay for, if you are lucky to get your plane back without cosmetic damage done during careless maintenance.

These aircraft are almost exclusively operated by private owners. They are not used for training, They have stall speeds and wing loadings often incompatible with General Aviation certification requirements. Spares are difficult if impossible to find (Sukhoi's) other than engine parts. There an an insignificant number of them around, and there is no company or factory back up to issue SB,s, mod's, improvements.

The paranoia of EASA for regulations it's that they will provide for certification under CofA for aircrafts which, because of the issues above, belong Experimental category, so to make them fit into the "Certified category", they embark into endless amendments, and produce so much waivers, that it ends up as a joke, a sad and expensive joke for owners...

Another example how bureaucracy has lost touch with realities, leading to a dead end. This is what happens when regulations are drafted by lawyers in the light of potential litigation prevention and not by qualified people.

One more thing: beware of YAK with fitted autopilot! All I know are illegal and the fastest way to get grounded ...