The S-400 is one of the most modern Russian air defense systems, with an extraordinary range.
The US military believes it has found a weak point in the air defenses of Russia and China. And like the Achilles heel, this vulnerability is very low. In particular, the service believes that the lower-tier air defenses of its main adversaries have a weak point.
When it comes to invading other countries, kicking in the door and clearing enemy air defenses is often left to the US Air Force (USAF) and its fleet of stealth jets. The United States Army, in its brown uniform, tanks and helicopters, usually arrives later, after the enemy’s air defenses, communications networks and air forces have been destroyed.
However, the service believes that it should play a leadership role in suppressing enemy air defenses. He argues that new helicopter technologies give him an advantage that his USAF brethren lack.
“The lower level of air dominance is, in fact, decisive,” says Brigadier General Walter Rugen, director of the US Army Future Vertical Lift Cross Functional Team. “We don’t have a problem with what those who do. they fly high. We can hide in disorder, appear at a time and place of our choosing to actually create chaos in the enemy’s decision cycle.
The US Army believes it can use terrain masking – that is, hiding from radar behind hills and in valleys – more effectively than ever. Using innovative flight controls that automate parts of low-level flight, the service believes it can fly its Future Attack Reconnaissance Aircraft (FARA) at higher speeds and lower altitudes than previously thought possible or safe.
“We are being very innovative in that space. Very, very innovative in terms of how low we can go, how fast we can go, ”says Rugen. “And so far, it is working. We have done a lot of races «.
The use of army helicopters to attack air defense systems is unprecedented. At the beginning of Operation Desert Storm in 1991 to liberate Kuwait, Boeing AH-64 Apache attack helicopters were used to fly low and destroy Iraqi radar sites. This created a coverage gap that was exploited by fixed-wing aircraft.
Stealth low flight
The claims by the US Army come as the Lockheed Martin F-35 Lightning IIs of the USAF, the US Navy and US Marine Corps, and other attack aircraft of low observability, they face increasingly sophisticated and lethal air defenses. In particular, US war planners are concerned about the Russian-made S-400 Triumf surface-to-air missile system, which Moscow says has anti-stealth capabilities.
That battery can hit air targets at ranges up to 135 nm (250 km), with a future missile upgrade possibly extending its range to 210 nm, according to the think tank of the Center for Strategic and International Studies (CSIS). After Turkey bought and received the missile system from Russia in 2019, Washington expelled its NATO ally from the F-35 program, saying the stealth fighter could be compromised.
Still, the S-400 has a problem. The weapon is optimized for hitting high-flying aircraft and needs protection against low-flying threats like stand-off munitions, cruise missiles or helicopters, says Ian Williams, deputy director of the CSIS Missile Defense Project. To protect it from low-altitude weapons, the Russian military typically surrounds the S-400 with short-range air defense systems, such as the Pantsir-S1 and cannon-equipped missile battery. “They always put them together with their longer range air defenses, to protect them from these types of threats,” Williams says.
In fact, the Pantsir-S1, also known by its NATO name SA-22 Greyhound, is exactly the kind of threat the US Army is eager to take on with FARA, which is scheduled to be deployed in 2028. .
“In the penetration phase of the Future Vertical Lift, we are certainly going after the SA-22 with our advanced entry tactics, techniques and procedures that we are developing,” says Rugen. “Then we go after the command and control vehicles. Then we go after the long-range enemy capability.
The United States Army wants the FARA to be an agile “knife fighter” that will duck and stand between enemy air defenses. It must have a cruising speed of at least 180 knots (333 km / h) and a rotor diameter of no more than 12.2 m (40 ft). The little helicopter is expected not only to hide behind hills, but among high-rise buildings in megacities.
However, hiding behind solid ground, or even between structures, is not a new concept. During the Cold War, the Rockwell B-1 Lancer variable-swept wing bomber was designed to fly low and close to the ground to avoid detection by radar-guided missiles in hypothetical nuclear strikes against the USSR.
The B-1B fell out of favor in its penetration attacks when it was discovered in the late 1970s that Moscow was developing a look-down / shoot down radar. Such radar would allow a higher-flying aircraft to detect incoming low-flying bombers against the backdrop of the ground without mistaking the aircraft for objects on the ground. Therefore, the penetration and suppression of enemy defenses mission was transferred to stealth aircraft, beginning with the Lockheed F-117 Nighthawk.
In the same way that the B-1B would be exposed to look-down / shoot down radar, it would appear that a helicopter with its many angles that reflect the radar, including the main and tail rotors, would be highly vulnerable.
Not so, says Rugen. Instead, the US Army believes that FARA can hide itself by flying extremely low to the ground, much lower than jet aircraft are capable of. Rugen declines to say how low and fast his next-generation scout helicopter will be able to fly, citing classification restrictions, but reiterates that the service’s “high-fidelity model” shows that the lower level of air dominance is “decisive.”
“It’s much easier to be seen when the air is clear and clean, higher than, depending on where you are, 300 feet, 1,000 feet or 3,000 feet above the ground,” says Rugen. “It is very anecdotal to say that they can look down and take down. I’ve seen very few reports of the ability to do that, if any. And I have not seen any model or test that has been able to demonstrate that they can do that in the most routine way possible with people who operate at the top level of air dominance.
Distinguishing FARA from the ground, a building or a moving vehicle would be difficult, he says. “There is a lot of disorder. A milk truck is a mess, right? Some of our things just fly as slow as a milk truck, ”says Rugen. “There is a lot to solve. I don’t know if anyone has an algorithm to do that.
However, the danger for FARA is that pilots could accidentally step out of the shadows of the radar and alert the enemy to their presence. “If we raise our heads too much, we get in trouble,” says Rugen. “But that’s where a lot of this cognitive offloading work that we’re doing comes in, to make sure we can fly as fast as possible, as low as possible.”
The US Army is working on several initiatives to make it easier for FARA pilots to fly low. For example, its “Holistic Situation Awareness – Decision Making” development program, launching in fiscal 2021, seeks data fusion technologies to simplify internal cockpit information and facilitate decision making by pilots, says a request for information published in April by the service.
Additionally, Bell and Sikorsky’s proposals for the FARA program are fly-by-wire helicopters that they say can be piloted optionally, which means that the aircraft’s flight computers should be capable of some precision autonomous flight without the pilot’s hand on the lever.
Bell is building the 360 Invictus, a winged helicopter with a tubed tail rotor and a backup auxiliary power unit; and Sikorsky is building the Raider X, a coaxial compound helicopter with a thrust propeller.
Rugen declines to discuss how automated low-flying would work or to name the companies that work on the FARA subsystems. It is also unclear to what extent these complicated maneuvers would be automated.
In fact, relying on a helicopter to fly only at high speeds, close to the ground, and obstacles in between is a huge engineering task. Just avoiding power lines, the number one deadly enemy of helicopters everywhere, requires constant attention from pilots.
However, the United States military wants to free pilots from the burden of flying. In April, the service sent a request for information on possible mission systems for the FARA. He requested sensors covering a 360 ° field of view to fly the helicopter in degraded visual environments, day or night. These sensors must be able to detect cables and obstacles in low light, as well as avoid collisions with the ground. “The FARA project manager is also interested in software solutions and applications that support supervised autonomy and optionally manned flight,” says the request for information.
The service recently practiced using undisclosed software to automatically divert the helicopter in bad weather and threats, Rugen says of the August and September “Project Convergence” exercises at Yuma Proving Grounds in Arizona. “Flying and entering, a lot of that will be automated because we understand the terrain. We understand what is going to come and maybe it will impact us on the ground, “he says.
Long range attack
However, penetrating Russian or Chinese airspace will require more than terrain-masking flight techniques. Both countries have layered missile defenses, including not only radar-guided short-range missile batteries, but also easy-to-conceal portable air defense systems such as shoulder-fired surface-to-air missiles (MANPADS).
To avoid weapons in the line of sight, such as heat seeking missiles fired from MANPADS, “the helicopters would operate in a relative sanctuary just outside the enemy’s weapons combat zone and flood the zone with air-launched effects. that push forward to detect, identify, locate and report the most dangerous threats that would then be attacked and attacked with long-range precision munitions, ”says Rugen.
The air-launched effects are a form of unmanned aerial vehicle (UAV) that the service plans to launch from General Atomics Aeronautical Systems’ FARA and MQ-1C Gray Eagle UAV. The United States Army wants the FARA to hide in clutter on the ground and use air-launched effects to spy behind enemy lines. The small drones launched from tubes would be used for intelligence, surveillance and reconnaissance missions, electronic warfare, decoys, and roaming ammunition.
Effects launched from the air could dramatically increase the vision and impact range of the FARA and could be networked to transmit information. “We’ve had our airdrop effects chained at about 61 km,” says Rugen of the Area I drone exercises at Project Convergence.
Once a target is detected, via an airdrop effect, the MQ-1C or the FARA, the service wants that information to be sent to any soldier, helicopter pilot, gunner or UAV operator with a weapon inside. of the attack scope (hence the name of the Project Convergence exercise). During recent exercises in Yuma, the US Army transmitted information about targets on the battlefield using TrellisWare software-defined radios and ruggedized tablets.
The United States Army also aims to speed up the process by which targets are detected and attacked. Accelerate the exercise process using an artificially intelligent program. “We are working with our ground partners to have simultaneous execution of targets at extremely fast speed, facilitated by software we call Firestorm that distributes target data to the correct shooter,” says Rugen.
Firestorm is even capable of automating Lockheed AGM-114 Hellfire air-to-ground missile firing from the MQ-1C. “If determined to be the best shooter, Gray Eagle is assigned the fire mission, the software on board the Gray Eagle automatically calculates the route and ammunition required to strike the target and sends it back to the commander on the ground, who must approve it, ”says Rugen. . “Then the Gray Eagle gets into position and executes the fire mission without further input.”
Ultimately, the US Army believes that this type of automation will give it an advantage.
“It’s really refining our chain of death, taking them from minutes to seconds,” says Rugen.