Su-15s and 27s, to be directed to targets spotted by MiG-31 (a maximum of four (long-range) for each MiG-31 aircraft). The A-50 AEW aircraft and MiG-31 can automatically exchange aerial and terrestrial radar target designation, as well as air defense. The MiG-31 is equipped with ECM of radar and infrared ranges. The flight-navigation equipment of the MiG-31 includes a complex of automatic control system SAU-155МP and sighting-navigation complex KN-25 with two inertial systems and IP-1-72A with digital computer, electronic long range navigation system Radical NP (312) or A-331, electronic system of the long-range navigation A-723. Distant radio navigation is carried out by means of two systems: Chayka (similar to the system of Loran) and «Route» (similar to the system of Omega). Similarly to the complex S-300 missile system, aircraft group with APD-518 can share data obtained by various radars from different directions (active or passive scanning of radiation) and summarize the data. The target can be detected passively (via its emissions of jamming or use of its radar) and/or actively simultaneously from many different directions (with the MiG-31 using its radar). Every aircraft with the APD-518 will have the exact data, even if it is not involved in the search. interacting with ground-based automated digital control system (ACS «Rubezh» Operating radius of , can control multiple groups of planes), operating modes of remote aiming, semi-automated actions (coordinate support), singly, and also: to direct on the target missiles launched from the other aircraft. Digital immune system provides the automatic exchange of tactical information in a group of four interceptors, remote one from another at a distance of and aiming at the target group of fighters with less-powerful avionics (in this case the aircraft performs the role of guidance point or repeater). Radars Adopted in 1981 RP-31 N007 backstop (Russian: Zaslon). the range of detection of air targets with Zaslon-A: (for the purpose of a radar cross-section of 19 m2 on a collision angle with probability 0.5) target detection distance with radar cross-section of in the rear within with a probability of 0.5 number of detected targets: 24 (was originally 10) number of targets for attack: 6 (was originally 4) range of automatic tracking: detection of infrared signature targets: Effective in the detection of cruise missiles and other targets against ground clutter Until 2000, it was the world's only fighter in service equipped with phased array radar, when the Mitsubishi F-2 entered