In 2012, the owner of Suprunov Designs, and author of the high-fidelity Yakovlev Yak-40 regional jet simulation for FS2004 died in a glider accident.
Since that time, the Russian flightsim community has uploaded the complete Yak-40 for FS2004 so that others may continue to gain enjoyment from Mr. Suprunov's creation. It is available here:
http://avsimrus.com/f/fs2004-aircrafts-40/...omments&hl=
Additionally, the community has been active in adapting the highly technical simulation for FSX as a port over. Over the past few weeks, they have made steady progress with some solid FSX iterations, and continue to work further to add additional functionality.
The latest version at the time of this writing is available from this direct link:
http://www.avsim.su/jump.phtml?http://yak4...-Yak-40_3-4.rar
As a side note about copyright, according to a commercial rep (unrelated) at English Avsim, a moderator on Russian Avsim said that this is legal. I have no further information.
http://forum.avsim.net/topic/411041-igor-s...0-now-freeware/
So, there you have it, a Yak-40. I'm still more of a Tu-154 person myself, but here's another desperately needed Soviet jetliner for FS.