Alex is correct, concerning the delay. This was published about two-three weeks ago by the Serbian minister of transport. I was really looking forward to having a nice addition of new aircraft to the JAT fleet this year, however we will have to wait
Nevertheless, JATs fleet-in-operation is not that old. The two Boeing 727-200s currently in operation were delivered in the early 1980s, ATR72s in 1990s, the Boeing 737-300s between 1985 and 1988. JAT has anyhow phased-out many of the DC9s and B727s from its operational fleet. Nine of these aircraft are currently out of operation, while another four aircraft are on storage infront of the main hanger at BEG.
All of the CFM56 engines on the Boeing 737s will be overhauled, thus extending the operational life of these aircraft. Overall, JAT will eventually take delivery from Airbus, as one aircraft (A319) has already been paid for.