How Can Helicopters And Planes Detect And Sink Submarines?

Two aircraft flying over a surfaced submarine

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It might seem counterintuitive to have an aircraft in the sky find something hiding deep under the ocean’s surface but not only is it a common task in the United States Navy, there are aircraft specifically designed to do so. This has been a mission for various aircraft since World War I when blimps hunted German U-boats. Of course that was before the age of nuclear power, before a military submarine could stay underwater indefinitely. Even though the crews of these submarine-hunting aircraft have a variety of systems at their disposal, it’s still like finding a needle in a haystack. The aircraft utilize both sonar and radar systems to detect these lurking leviathans. When they find their prey, they drop aerial torpedoes.

Sometimes the search can be a general search over a wide area while other times it can be based on intelligence received from other sailors at sea. When the aircraft reaches the area a submarine is suspected of hiding, they’ll drop the sonobuoys, which are basically a giant microphones. The moment a sonobuoy impacts with the water, an inflatable cushion deploys, keeping a radio transmitter on the ocean’s surface to communicate with the aircraft while hydrophone sensors and stabilizing equipment descend to anywhere between 90 and 1,500 feet, depending on the submarine being hunted.

Most submarine-hunting aircraft arm themselves with aerial dropped torpedoes when necessary, but most of the time the aircraft is there to act as a deterrent. The Navy simply wants to know where the submarines are and let them know they know.

Sonobuoys aren’t the only tracking system

P-8 Poseidon crew watching instruments in the cabin

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Older United States Navy aircraft were also equipped with a magnetic anomaly detector that was a long cylinder protruding from the aircraft’s tail. This was often referred to as the plane’s “stinger.” It wasn’t a weapon like that found on a wasp, but rather a sensor that detected the smallest of disturbances in Earth’s magnetic field, specifically those caused by large metallic objects like a 300-foot submarine. Hunting submarines, whether from the air or right in the water with them, is a lot like playing real-life “Battleship,” figuring out where the submarine isn’t before finding its exact location.

The U.S. Navy also utilizes an advanced sensor that tracks submarines in the most unthinkable way possible. Rather than using sonar or magnetic detection, this new sensor simply uses radar, but what it’s actually doing is locating the wake left behind a submarine. Unlike traditional radar systems that use a large dish, the Raytheon AN/APS-154 Advanced Airborne Sensor will be sit within an unassuming pod underneath an anti-submarine warfare aircraft. It’s a solid-state array without any moving parts that can scan a broad 360-degree view or a more focused, pinpoint area.

The AN/APS-154 can track objects as small as an individual person from high above the clouds and provide a clear, monochrome image. Moreover, it functions over multiple frequencies that helps in preventing adversaries from jamming it.

The aircraft that hunt submarines

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The U.S. Navy had a versatile aircraft designed to hunt its underwater prey in the S-3A Viking, but it has since upgraded to the larger P-8 Poseidon. The Navy’s Poseidon is so much scarier than it looks, specifically for submarines. It’s a militarized version of Boeing’s 737-800ERX that seats a team of nine, including three pilots, a tactical coordinator, a co-tactical coordinator, two acoustic operators, and two electronic warfare operators. It doesn’t utilize a magnetic anomaly detector like its predecessor, but it does deploy sonobuoys and has Raytheon’s Advanced Airborne Sensor. It also has the ability to drop Mk. 54 torpedoes and launch cruise missiles.

The Navy uses is a variant of the UH-60 Black Hawk, the MH-60R Seahawk. Unlike the P-8 Poseidon, it fulfills a variety of roles, including hunting submarines as well as surface vessels. On top of the ability to launch sonobuoys, the Seahawk is also equipped with a Raytheon AN / AQS-22 low-frequency dipping sonar and a forward-looking infrared sensor. In the event that a Seahawk has to engage with a submarine, it can launch lightweight torpedoes. This doesn’t include the aircraft that other navies around the world use, though many American allies purchased the SH-60B variant of the Seahawk.