Inside the Helicopter NATO Warships Lean on to Find Russian Submarines

ABOVE THE NORWEGIAN SEA — The sleek, gray NH90 helicopter cut through the brisk Arctic air, leaving the jagged coastal mountains and fjords behind. From above, the frigid blue waters below showed no signs of life.

The helicopter wasn’t on the hunt when Business Insider flew from Tromsø, Norway, out to the Royal Netherlands Navy frigate HNLMS De Ruyter, but it’s built for that mission.

Had a Russian submarine been lurking below the surface, as they often do in this remote part of the world, the helicopter could have employed its powerful dipping sonar and other advanced — and secretive — equipment to find the hidden boat.

The flight out to the Dutch frigate, the lead ship of Standing NATO Maritime Group 1, as it was conducting operations in the Norwegian Sea, was merely an airport transfer; however, the NH90 plays an integral role in anti-submarine warfare, one of the standing group’s key missions in this latest deployment.

Several of De Ruyter’s crew members described the helicopter as essential to its sub-hunting capabilities. “It’s a fantastic asset,” British Lt. Cdr. Michael Royle, the staff anti-submarine warfare officer aboard De Ruyter, said of the NH-90. He described the helicopter as a valuable “force multiplier.”

‘A big addition’ to the warship

The NHIndustries NH90 is a twin-engine multirole helicopter made by a consortium of European companies and is in service with nine NATO militaries, including the Netherlands. Although they aren’t members of the alliance, Oman, Qatar, and New Zealand also operate the aircraft.

The NH90 was developed to satisfy NATO’s need for a helicopter that could operate in naval environments. Since the aircraft made its first flight in the mid-1990s, over 500 of them have been built in two variants — an army transport version and another that can be embarked on frigates like the De Ruyter.

One of the NH90’s main mission sets is anti-submarine warfare. It is equipped with dipping sonar — a deployable underwater sensor that emits pulses and analyzes echoes — and expendable sonar buoys, which rely on acoustic sensors to track submarines and potential threats underwater.

The helicopter is relatively spacious. Two pilots sat in the cockpit, while a third crew member sat in the back. At one point, as the aircraft approached De Ruyter, he slid open the door, giving way to a blast of Arctic breeze. The NH90 is full of sensitive equipment, so much so that Business Insider was not permitted to take photographs of the interior.

Royle said that the sonar system can be dropped into the sea at “a big depth;” he declined to say how deep. “That allows you to exploit the water column in order to get the massive ranges for sonars to be able to potentially detect submarines.”

Dutch Cpl. Duncan, a NH90 maintainer with the De Ruyter who was only authorized to use his rank and first name for security reasons, told Business Insider that by deploying both the sonar and the buoys, “you can determine the exact spot and triangulate where something — or someone — could be.”

The NH90 helicopter can also operate in bad visibility, which can be a challenge in the Arctic region, making it an important tool in countering Russia’s submarine force.

Russia fields one of the largest submarine fleets in the world, with an estimated 64 active boats. Dozens of boats belong to its Northern Fleet, based in the Murmansk region along the Barents Sea. To get to the Atlantic and Mediterranean as quickly as possible, they have to sail through the Arctic and head west around the northern tip of Norway, through the waters where Standing NATO Maritime Group 1 was operating last week.

In recent years, top Western military officers have drawn attention to growing Russian submarine and naval activity in the Atlantic, among other waterways. There is also increasing concern in Europe about damage to critical underwater infrastructure; in January, NATO deployed military forces to the Baltic Sea to respond to sabotage incidents.

Commodore Arjen Warnaar, the Dutch commander of the Standing NATO Maritime Group, told Business Insider that countering submarines is one of the De Ruyter’s main tasks on its current Arctic deployment.

“One of the main reasons for me to be here is to increase our readiness. So that’s basically what we’ve been doing up north,” he said.

“We’ve been exercising all kinds of different operations,” Warnaar explained. “Surface warfare, anti-submarine warfare — just basic picture compilation, replenishment, logistics are important. And at the same time, we’ve been having a good look around.”

NATO forces operate several other aircraft equipped to track down Russian submarines, such as Boeing’s P-8 Poseidon or Lockheed’s P-3 Orion. These planes, while well-equipped, are less flexible than helicopters like the SH-60 Seahawk or NH90 because they operate from airfields rather than ships at sea, limiting time on site.

Cpl. Duncan called the helicopter “a big addition” to De Ruyter because it can extend the range of the warship’s anti-submarine warfare capabilities.

“The range extension of the sonar is an important aspect because of the abilities of detecting, seeing, and determining if there are any contacts on the water,” he explained, adding that the helicopter can clear water columns of potential threats — also known as sanitizing the area — before the ship moves into the space.

Adm. Stuart Munsch, the commander of US Naval Forces Europe-Africa, previously told Business Insider that anti-submarine warfare is one of the hardest missions to execute in naval operations. However, he said NATO forces have become increasingly proficient at this task in the Atlantic Ocean and in the High North region.