The Russian news organization Baza has produced a story detailing how one MiG-31 accidentally shot down another in 2017.

Two MiG-31s in flight
Photo: Fedor Leukhin (Wikipedia)

The two interceptors were engaging a target drone when the wing-man accidentally targeted the lead plane instead. Due to a fault in the IFF system, the MiG’s backseater did not realize the error, and two live R-33 (NATO calls them AA-9 Amos) were launched. Apparently the other MiG’s RWR was working, as they were able to eject before the airplane was destroyed.

An R-33 mounted underneath a MiG-31 at the 1999 Moscow Air Show
Photo: Jno~commonswiki (Wikipedia)

The crew of the targeted MiG survived, and the crew of the targeting MiG was found to have committed a “violation of safety measures and missions for flight, expressed in the premature activation of the aircraft’s on-board radar station by the navigator and the unauthorized launch of the R-33 guided missiles by the commander,”