As my wife is from Ukraine I've been interested in this and from what I can find out the Ukrainian government are planning a maximum age of twenty years for all jet powered passenger aircraft, this is mainly due to the number of incidents with older aircraft, I believe the recent incident with Bravo airways MD-83 at Zhulyani and the constant delay after delay due to the maintenance issues on older aircraft is causing the government to take action. As far as I can find out freight aircraft and prop passenger aircraft will not be part of the age limit, but this is likely to change in due course. This is likely to see the demise of one or two Ukrainian airlines who only use older aircraft. A family friend told me that Motor Sich are looking to replace some aircraft with modern aircraft in the next couple of years.