The MB-339 is a jet trainer developed in the 70s for the Italian air force and was used by the Frecce Tricolore (their equivalent of the Red Arrows) The Skyhawk is a carrier capable light attack aircraft developed in the 50s for the US Marines, but was used by other air forces, notably the Argentinians. I have tried 4, some seem to be buggy resulting in a game crash but hopefully this will be fixed over time. It turns out there are a few free mods, some are based on planes in the game but some do not seem to be. However I like variety and even though I have a reasonable amount of modules I like to try new planes. I have been practicing flying aircraft in DCS, I haven't relearnt how to use the weapons, but for now just flying around is enough.