Minelayers.

This is coolbert:

Guards Minelayers. The Russian tradition continues!

Courtesy the article as seen at the Internet web site isegoria.net

"Aviation mines use an acoustic-infrared sensor to identify the noise of an aircraft up to 3.2 km away and then launch a projectile when it’s within 150 meters"

"Russia designed aviation mines in the late 1990s"

Described as anti-helicopter mines. Fires when acoustic and infrared signature of a rotary-wing low-level aircraft in the area. Automatically activates sending a spew of projectiles toward the target.

See also from the Internet web site "19fortyfive" as further described of this Russian anti-aircraft mine.

"Helicopters Beware: Russia Is Deploying Anti-Helicopter Mines"

Additionally think of a similar weapon from the era of the Cold War. Soviet special purpose ranger/commando Spetsnaz units employing an acoustically fired MANPAD SA-7 Grail missile.

As described by the Soviet defector Suvorov:

"Spetsnaz. The Story Behind the Soviet SAS"

Chapter 9: Weapons and Equipment:

"On the subject of mines, we must mention a terrible spetsnaz weapon known as the Strela-Blok. This weapon was used in the second half of the 1960s and the first half of the 1970s. It is quite possible that by now it has been very substantially improved. In a sense it can be described as an anti-aircraft mine, because it operates on the same principle as the mine laid at the side of a road which acts against a passing vehicle."

"The Strela-Blok is an ordinary Soviet Strela-2 portable missile . . . A spetsnaz group carries one or several of these missiles with it. In the area of a major airfield the launch tube is attached to a tall tree . . . nd camouflaged. The missile is usually installed at a short distance from the end of the runway. That done, the group leaves the area. The missile is launched automatically. A clockwork mechanism operates first, allowing the group to retire to a safe distance, then, when the set time has run out . . . a very simple sound detector is switched on which reacts to the noise of an aircraft engine of a particular power. So long as the engine noise is increasing nothing happens . . . but as soon as the noise decreases the mechanism fires. The infra-red warhead reacts to the heat radiated by the engine, follows the aircraft and catches up with it."

Consider then these anti-helicopter mines as a version of the Strela-Blok but more sophisticated and going to be used on a much more massive scale.

coolbert.