Russia’s integration of the A-50 radar plane and the S-400 surface-to-air missile system speeds up in response to anticipated Ukraine’s deployment of Western-provided combat aircraft, as Russia may accept more risks flying the A-50 closer to the frontlines, according to the UK Defense Ministry’s intelligence update published on 17 November.

The ministry tweeted:

• For the first time, Russia has likely started using A-50 MAINSTAY D, its Airborne Early Warning and Control aircraft, to identify targets over Ukraine for its SA-21 long-range ground-based air defence missile system. This adds to MAINSTAY’s core mission of co-ordinating fighter aircraft.
• Compared to SA-21’s usual ground-based radar, MAINSTAY can use its radar to spot adversary aircraft at longer ranges because its altitude allows it to see further around the curvature of the earth.
• Russia has likely expedited integrating MAINSTAY and SA-21 partially because it is concerned about the prospect of Ukraine deploying Western-provided combat aircraft. There is a realistic possibility that Russia will accept more risk by flying MAINSTAY closer to the front-line in order to effectively carry out its new role.

The Mainstay is the NATO reporting name for Russia’s Beriev A-50 a Soviet-developed airborne early warning and control aircraft based on the Ilyushin Il-76 transport. The SA-21 Growler is the NATO designation for Russia’s S-400 Triumf mobile surface-to-air missile (SAM) system.

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