‘Stay Down Low’: Ukraine Fears Formidable Russian Air Defenses in the Donbas

The Ukrainian military is increasingly concerned that Russia is creating anti-access air zones in the contested Donbas region to keep Ukrainian aircraft from flying through the area, limiting Ukraine’s ability to support its ground forces. While U.S. officials believe that Russia’s progress in the region has been slow and uneven so far, with troops wary of fighting beyond their supply lines, the introduction of more Russian S-400 air defense batteries and drones, as well as low cloud cover in the region, has left Ukrainian pilots uniquely vulnerable.

“They created in the Donbas a powerful [anti-access/area denial] zone, and in these circumstances, it is really dangerous to fly over them,” one Ukrainian official told Foreign Policy in an interview, speaking on condition of anonymity because they were not authorized to speak to the media. “In low altitude, the Russian air defense is waiting for us.”

The Russian air defense zones have also complicated Ukrainian military plans to ask for more U.S. and Western-owned fighter jets, especially Soviet-era MiG-29 aircraft. The Ukrainian military hopes to use new jets to force Russian planes lower in altitude, where they can be targeted by surface-to-air missile batteries or shoulder-fired Stinger missiles.

Officials and experts believe that the more concentrated deployment of Russian forces in the Donbas means that the air defenses there are denser and better coordinated. But a senior U.S. defense official said on Monday that Russia is keeping most of its air defenses for the Donbas fight over the border.

“That’s always been a thing,” said one congressional aide, speaking on condition of anonymity because they weren’t authorized to speak with the media. “In the Donbas, they’re protected under the umbrella of the [Russian] Western Military District. You’re not just dealing with what they have in Ukraine on Ukrainian territory and in the separatist republics, but you’re also dealing with the systems that are in Mother Russia. They’re going to have much better air defense and denial than they would anywhere else.”

But Ukrainian aircraft have also faced threats from upgraded Russian anti-aircraft systems, necessitating a restocking of jets. “We are losing our planes not every day, but we are losing them,” the Ukrainian official said. “Of course we need a new supply of these jets.”

NATO nations have provided enough spare parts for the Ukrainians to get 20 more MiGs flying again, senior U.S. defense officials have indicated, but Ukraine is focused on using them to help push back Russian forces in Mykolaiv and Odesa, the Ukrainian official said, as the Biden administration has warned of Russia’s desire to create a land bridge running from Crimea into the Donbas.

And over the weekend, the possibility of Ukraine getting more fighter jets appeared increasingly likely. The New York Times reported that Slovakia and Poland had reached a deal for joint air policing, allowing Polish F-16s to patrol Slovak skies and the potential for Soviet-made MiG fighter jets to move forward into Ukraine.

With Russia still not in control of Ukraine’s skies nearly 70 days into a war that Western intelligence officials first estimated could be over in a matter of hours, Russian pilots remain wary of entering Ukrainian airspace to conduct raids, fearing Ukrainian surface-to-air missile coverage. U.S. and British officials believe that most Russian strikes are being fired from western Russia or from the Black Sea. And Ukraine’s air defenses could yet improve, with more Russian-made S-300 air defense batteries coming in from Eastern Europe and German “Cheetah” air defense tanks on the way.

Ukraine’s sorties have helped keep its MiG jets alive, moving them around so Russia cannot locate and destroy them. But part of its strategy is also to try to force the Russians to fly at different altitudes, giving the Ukrainians a better shot at hitting Russian jets with surface-to-air missiles. Ukraine’s military said in an update on Monday that it had destroyed 194 aircraft, 155 helicopters, and 271 Russian drones since the start of the war.

“If either side materially increases the ability to use air power, that would make a big difference in their favor and might preempt a ground slugfest,” said Phillips O’Brien, a professor of strategic studies at the University of St. Andrews in Scotland. “Otherwise, a slugfest is probable, if the Russians can concentrate enough power and not have it frittered away.”

Despite Russia’s air advantages in the Donbas, including higher freedom of action in the air than in other parts of the country, experts said it hasn’t been able to press the initiative so far. U.S. officials have noted that harsh Western sanctions and export controls have limited Russia from restocking inventories of precision-guided munitions, forcing the Kremlin to rely on “dumb bombs.” Justin Bronk, a senior research fellow at the Royal United Services Institute, a London-based think tank, said Russia’s lack of targeting pods, cloud cover, and limitations in sensor coverage and ground controllers had limited its ability to hit military targets that are on the move.

But the low cloud cover could also give Ukrainian pilots more incentive to emphasize a game plan based on staying low for short periods of time, where they could be out of detection range for Russian radars. Experts believe early footage of the so-called “Ghost of Kyiv” that reportedly shot down 40 Russian pilots in the first days of the war was likely pieced together from different sources, but the tactical blueprint is still sound.

“The tactics that they showed in those little clips were exactly what the Ukrainians would need to do to be able to just survive, to stay down low out of the S-300 and S-400 threat that the Russians have, where you’re in the ground clutter of Russian radars,” said John Venable, a retired U.S. Air Force colonel who now serves as a senior research fellow at the Heritage Foundation. “When you choose to engage and you pop out of that environment, you have one shot at that. And if you’re successful and you knock down one of the Russian fighters, that’s a huge win.”