Talk about your modern-day David versus Goliath stories. It seems that a $400 Ukrainian drone has taken out a $300 million Russian early warning and control aircraft. The Beriev A-50 is sometimes referred to as Russia’s “eye in the sky”. Its NATO reporting name is Mainstay.

The Fall of the Mainstay

In a move that would make even the most seasoned war strategists do a double-take, Ukraine’s Security Service (SBU) executed Operation Spiderweb on June 1, 2025. This audacious operation saw over 100 first-person-view (FPV) drones, some costing as little as $400, launched from concealed positions deep within Russian territory. Their targets: major Russian airbases, resulting in the destruction or damage of at least 41 aircraft, including the prized Beriev A-50 “Mainstay” airborne early warning and control (AEW&C) aircraft. 

The Beriev A-50 “Mainstay” is Russia’s flying radar dome—a Cold War dinosaur that’s somehow still lumbering through modern skies. Developed by the Beriev Aircraft Company and packed with radar tech from Vega-M, the A-50 is essentially a Soviet clone of the U.S. E-3 Sentry. It rides on the back of the Ilyushin Il-76 airframe, a heavy-lift military transport repurposed into a high-altitude command post. The A-50 made its first flight in 1978 and officially joined the Soviet Air Forces in 1985. It was built to keep tabs on NATO bombers, cruise missiles, and anything else sneaking around the edge of Soviet airspace. And in a way, it still serves that same role today—for a fraction of the original fleet.

Only about 40 of these aircraft were ever made. Of those, fewer than ten are thought to be flight-ready now, thanks to the usual suspects: aging airframes, sanctions squeezing parts supplies, and the general entropy that comes with trying to maintain 40-year-old flying radar trucks. The A-50 was never meant to fight wars forever, but here we are, 2025.

What makes the A-50 matter is what’s sitting on its back: a giant 30-foot rotodome housing theShmelradar system, sometimes calledLiana.This thing can spot incoming air targets from up to 650 kilometers away, and it can see ground targets at a range of around 300 kilometers. The radar can track 50 or 60 targets at once, feeding targeting data to fighter jets, surface-to-air missile systems, and command posts. It’s not just a passive observer; it’s a coordinator, able to guide up to ten aircraft into combat at the same time. Think of it like a flying quarterback calling plays and keeping the team in formation.

Inside, it’s a packed house—15 to 20 crew members including pilots, radar operators, and mission planners all crammed into the belly of this beast. These aren’t comfy commercial flights. It’s all business in the sky: long missions, cold interiors, and a crew glued to their screens while the world burns beneath them.

Over the years, the A-50 has had a few updates. The original version ran on analog guts—those are mostly phased out now. The A-50M added some upgraded nav gear, but the real leap came with the A-50U. That’s the modernized version with digital avionics, satellite comms, and a better radar picture. Only a few of the active fleet have been brought up to this standard, which makes each A-50U worth its weight in rubles and then some.

The Mainstay is crucial for Russia’s air dominance strategy. It extends radar coverage far beyond what ground stations can manage. Ironically, it helps detect low-flying drones and cruise missiles trying to sneak in under the radar. It’s the glue in the Russian integrated air defense system, especially when operating over hostile territory or near contested borders. That’s why it’s deployed to hot zones like Syria, Crimea, and Ukraine.