MOSCOW (AP) _ A military newspaper today identified the new head of Soviet air defense forces, whose predecessor was fired when a West German teen-ager flew a plane unimpeded over Soviet air space and landed it near the Kremlin.

Western military attaches said Gen. Ivan M. Tretyak was commander of the Soviet far eastern military district when a Soviet fighter shot down a Korean Airlines jumbo jet that strayed into Soviet airspace. All 249 people aboard the Boeing 747 were killed in the Sept. 1, 1983, attack.

The military newspaper Red Star identified Tretyak as the new head of Soviet air defense forces. It said he addressed the top Communist Party members of the forces on the role of Communists in strengthening military preparedness.

Tretyak had been named commander of the Soviet far eastern military district in May 1976.

The ruling Politburo fired the previous head of Soviet air defenses, Chief Marshal Alexander I. Koldunov, on May 30, two days after 19-year-old Mathias Rust flew from Helsinki, Finland, to Red Square.

In its report on the flight, the Politburo said the West German had been spotted by radar and Soviet fighters, but that nothing was done to make him break off his flight.

The wording of the Politburo statement indicated that the defense forces should have forced Rust to land, rather than shoot him down.

The day of Koldunov's firing, Defense Minister Sergei L. Sokolov was retired and replaced by Gen. Dmitri T. Yazov, who served as commander of the far eastern military district after Tretyak.

It was not known if Tretyak and Yazov had served together in the district.

The Western defense attaches, who spoke on condition of anonymity, said it was also not certain when Tretyak left the far eastern district, whose headquarters are in Vladivostok. They said he had recently been working in Moscow.