Twenty Russian Glide-Bombs Pummel Ukrainian Forces Every Day. Some Weigh A Whopping 3,300 Pounds.

It’s no secret that, after 14 months of hard fighting, Ukrainian forces are running low on surface-to-air missiles. For the Russians, this is an opportunity.

For more than a year, Ukraine’s air-defense batteries have held off the Russian air force’s hundreds of modern fighter-bombers. To bombard Ukrainian targets beyond the front line—cities, military bases, power plants—the Kremlin has to reach into its dwindling stockpile of (expensive) long-range cruise and ballistic missiles.

The slim cost-benefit margin of long-range missile strikes has constrained the Russian air campaign. But as Ukraine’s SAMs run out, the calculus is shifting. More and more, Russian jets are finding gaps in Ukrainian air-defenses—and flying toward them to lob crude glide-bombs.

These winged bombs, rough analogs of Ukraine’s own American-made JDAM-ERs, aren’t terribly accurate. But they don’t always have to be very precise when some of them pack a whopping 2,000 pounds of high-explosive. Better yet for the Russians, the handmade glide-bombs are cheap. Perhaps just a few tens of thousands of dollars apiece.

For the first year of Russia’s wider war on Ukraine, stiff Ukrainian air-defenses—dozens of long-range S-300 and medium-range Kub and S-125 batteries plus scores of mobile Buk launchers and many hundreds of shoulder-fired short-range missiles—effectively protected most of Ukraine from Russian attack planes.

The Russian air force and navy lost scores of jets trying and failing to roll back these defenses. The Ukrainians never fully controlled the air over all of Ukraine. But then, neither did the Russians.

“Without air superiority, Russia’s attempts at strategic air attack have been limited to expensive cruise and ballistic missile barrages at a much more limited scale,” Justin Bronk, Nick Reynolds and Jack Watling from the Royal United Services Institute in London wrote in their definitive study of the Ukraine air war’s early months. “These failed to achieve strategically decisive damage.”

The aerial stalemate didn’t last forever. Most of Ukraine’s SAM launchers fire Soviet-made missiles. Once the ex-Soviet stocks run out, the Ukrainians realistically will have two options: acquire replacement missiles from abroad, or swap out Soviet-style air-defenses for Western systems, missiles for which Kyiv can get from its European and American allies.

In fact, Ukraine has chosen both options. It’s gotten a few S-300, S-125 and Buk launchers and missiles from Slovakia and Poland. The United States and Canada and various European countries have pledged an array of air-defenses including long-range Patriots and medium-range NASAMS and IRIS-Ts, among others.

But the Western systems so far have been too few, and too late, fully to replace the old, ex-Soviet systems. After firing dozens of S-300 and Buk missiles every day for more than a year, the Ukrainians are expected to run out of Buks this month and S-300s next month.

As Patriots and other new launchers and missiles are just beginning to arrive, the result is expanding gaps in Ukraine’s air-defenses. The Ukrainians know it—hence their increasingly urgent pleas for more and better SAMs and also Western fighter jets.

The Russians know it, too. And they’ve rushed to exploit the gaps, by fitting plentiful bombs with simple wings and dropping them from medium or high altitude along sectors of the front line where Ukrainian SAM coverage is thinnest.

It started last month. On or before March 4, a Russian jet tossed what appeared to be a UPAB-1500V glide-bomb at a target in Chernihiv Oblast. Chernihiv city lies 25 miles south of the Russian border. It just so happens that a 3,300-pound UPAB-1500V—at least a ton of which is warhead—should travel around 25 miles if the launching plane releases it at 40,000 feet or higher.

Before recently, it would’ve been extremely risky for an Su-35 or Su-34 to approach the Ukrainian border at such high altitude, from where it would be visible to a host of Ukrainian radars. Now that Ukrainian air-defenders are running out of missiles, however, it’s much easier for a Russian Sukhoi to climb high, zoom toward the border, drop its UPAB-1500V then turn, dive and escape.

Easier, but not easy. Ukrainian air force spokesman Yuriy Ignat on March 5 claimed the air force shot down one Russian Su-34 while its crew was attempting a glide-bombing run.

The UPAB-1500V and the smaller FAB-500 glide-bomb broadly are similar to the Australian-designed, American-made JDAM-ER, a kit that combines GPS guidance and pop-out wings to give a standard dumb bomb the potential to strike pinpoint targets as far as 50 miles away. The Russian munitions home in on coordinates from the GLONASS satellite-navigation system, Russia’s less-precise version of the American GPS.

Ukraine is modifying some of its warplanes—Mikoyan MiG-29s, apparently—to drop JDAM-ERs, and there are reports of reliability problems with the sophisticated munitions as Ukrainian technicians and their American advisors improvise interfaces between the old Soviet jets and the new U.S. weapons.

The UPAB-1500V might also have problems. On April 20, a 3,300-pound UPAB-1500V or unguided FAB-1500 fell from a Russian fighter taking off at an airfield in Belgorod in southern Russia, 20 miles from the Ukrainian border. The resulting impact dug a deep hole in a city block and injured two people. The Kremlin described the incident as “an irregular flight of aviation ammunition.”

The small FAB-500 glide-bombs might be even less reliable and less accurate than the FAB-1500Vs are. A photo of a FAB-500 with a wing kit that circulated online early this month underscores just how crude the weapon is. The wing kit has visible welds. The interface between the bomb and pylon includes cheap commercial electrical components. It’s apparent Russian industry developed the FAB-500 glide-bomb quickly—and is building copies one at a time, more or less by hand.

All the same, the glide-bombs are making a difference. The Russians lately have been dropping as many as 20 of them every day, according to Ignat.

To deter the Sukhois carrying the munitions, Ukraine needs more air-defenses, Ignat said. That means more Patriots, NASAMS and IRIS-Ts—and also “fighters that can use air-to-air missiles at long distances.” In other words, American-made F-16s with AIM-120 missiles.