Syrian rebel forces have posted a video showing a MiG-23 being shot down over Al Muhassan, a small town near Dayr az-Zawr, 280 miles northeast of Damascus. The state media is claiming that the plane went down because of mechanical problems, and the rebels claim they were able to hit the MiG with anti aircraft fire. They published this to YouTube as proof.
The Syrian official news agency claims that the pilot was able to eject before the plane crashed.
The Mikoyan-Gurevich MiG-23 Flogger is a third-generation Russian fighter with variable wings built in the 1970s. The first MiG-23s reached Syria during the Yom Kippur war against Israel, but never saw combat in that scenario because the war was over before the Syrian air force managed to assemble and test the planes sent in crates from the Soviet Union.