The Avia S-199 is a propeller-driven fighter aircraft built after World War II, notable as the first fighter obtained by the Israeli Air Force, and used during the 1948 Arab-Israeli War. Constructed in Czechoslovakia, with parts and plans left over from Luftwaffe aircraft production, the aircraft had numerous problems and was generally unpopular with its pilots. Czechoslovak pilots nicknamed it Mezek ("Mule"), while in Israel it was officially known as the Sakeen ("knife" in Hebrew).