Russia’s Best Missile Can Hit Ukrainian Jets From 80 Miles Away. But Ukrainian Pilots Know How To Dodge.

Ukrainian air force pilots have worked out methods for dodging the Russian air force’s far-flying Vympel R-37M air-to-air missiles, according to one Ukrainian pilot.

“We created different tactics for how to avoid this missile—and that’s why it’s not so succesful against our jets,” Ukrainian Mikoyan MiG-29 pilot “Juice” told Lithuanian broadcaster Delfi.

The R-37M isn’t scoring a lot of hard kills, according to Juice. But it is forcing Ukrainian pilots to break away from their planned flight paths in order to perform evasive maneuvers.

That could count as a “soft kill.” Even when it doesn’t shoot them down, the R-37M might be preventing Ukrainian pilots from completing their missions.

It’s no secret the Russian air force has failed to achieve air superiority in the sky over Ukraine. Hamstrung by inflexible procedures, desperately short of precision weaponry and battered by stiff Ukrainian air-defenses, the Russian air arm at best is holding its own, despite a 10-to-one numerical advantage in fighters and attack jets compared with the Ukrainian air force.

The three regiments flying the Russian air force’s best interceptor—the twin-engine, two-seat Mikoyan MiG-31BM—are the rare winners. MiG-31 crews, flying high-altitude defensive patrols along the ever-shifting front lines and firing the powerful R-37M, reportedly have shot down several Ukrainian jets.

The Russians’ defensive patrols “have proven highly effective against Ukrainian attack aircraft and fighters, with the MiG-31BM and R-37M long-range air-to-air missile being especially problematic,” Justin Bronk, Nick Reynolds and Jack Watling wrote in a study for the Royal United Services Institute in London.

The MiG-31 flies higher, faster and farther than the Ukrainian air force’s best Sukhoi Su-27 interceptors. The heavyweight Russian fighter can fly as high as 60,000 feet out to 450 miles and dash at Mach 2.5 for short periods.

From their lofty perch, MiG-31 crews can search for targets with the jet’s Zaslon radar and fire a single, underbelly R-37M at targets as far as 200 miles away, although the missile works best at ranges no farther than 80 miles. A Ukrainian Su-27 by contrast can fire a Vympel R-27 missile no farther than 50 miles.

“The VKS has been firing up to six R-37Ms per day during October,” Bronk, Reynolds and Watling wrote, “and the extremely high speed of the weapon, coupled with very long effective range and a seeker designed for engaging low-altitude targets, makes it particularly difficult to evade.”

But not impossible to evade. Juice didn’t explain how Ukrainian pilots are dodging the R-37M shots, but it’s possible to guess.

For very long range shots farther than 80 miles, a MiG-31 crew detects a target with its own radar and fires the R-37M in the target’s direction. The missile immediately goes ballistic before diving down at six times the speed of sound.

For shots inside 80 miles, the missile flies a flatter trajectory at somewhat slower speed. In either case, at a distance no farther than 20 miles from its target, the missile switches on its own radar seeker and homes in.

But it’s possible to spoof the R-37M’s onboard 9B-1103M-15 seeker. The 9B-1103M-15 like many modern radars works by interpreting the Doppler shift of the radar energy bouncing between the radar and a target.

To understand Doppler shift, imagine a spring. Squeeze the spring, and its coils get closer. Stretch the spring, and the coils are farther apart. Doppler shift is the movement of the “coils” of electromagnetic energy between a radar and a target.

To avoid cluttering up a pilot’s screen, a Doppler radar has a “velocity gate.” It ignores slowly-moving or stationary objects such as trees and buildings. To disappear from Doppler radar, you could try to reduce your velocity relative to the radar.

What that means, for a fighter pilot, is flipping upside down, pulling back hard on the stick and diving. Pop some radar-foiling chaff for good measure and you just might trick the incoming missile. “Notching” is the term for this tactic.

Notching is a tried-and-true method of evading long-range missiles. It works best when the evading pilots has some altitude to spare. For Ukrainian pilots, who often fly at low level to avoid Russia’s ground-based air-defenses, diving in order to notch might not always be feasible. A perpendicular turn is a possible substitute.

But notching only works when you know the missile is incoming. A Ukrainian pilot’s radar-warning receiver should register the R-37M’s seeker once that seeker activates, 20 or so miles out. That should give the Ukrainian a few seconds to dive or turn.

If the pilot isn’t attentive to his RWR, he won’t have time to maneuver. “If you’re not aware of the launch of this missile, you’re dead,” Juice said.

It’s possible to imagine Russian MiG-31 crews, patrolling along the Russia-Ukraine border and lobbing R-37Ms at any Ukrainian jets they detect. It’s equally possible to imagine Ukrainian crews diving or turning to avoid most of the missiles.

Even when the R-37Ms miss, all that hard maneuvering still has the effect of disrupting Ukrainian sorties. “Sometimes we are forced to cease our offensive missions,” Juice said.