This new air-to-air missile appears to be the US Navy's answer to the growing reach of China's weapons

• US Navy fighter jets have been spotted carrying the air-launched variant of the SM-6, known as the AIM-174B.
• It looks to be a major upgrade for the US arsenal, boasting a longer range than other air-to-air missiles.

The US Navy is extending the reach of its fighter aircraft with a new long-range air-to-air missile only recently made operational, a weapon needed for a potential conflict with China.

The missile helps to close the gap between US capabilities and those of China, which is fielding new beyond-visual-range air-to-air missiles with reach.

The air-launched version of the Standard Missile 6, which is known as the AIM-174B, was spotted in photos by experts and analysts during its development; however, the details of the program were a bit unclear at the time.

The Navy acknowledged the AIM-174B in July when US Navy F/A-18E Super Hornets aboard the Nimitz-class aircraft carrier USS Carl Vinson and at Hawaii's Joint Base Pearl Harbor-Hickham were seen sporting the missiles during the Rim of the Pacific Exercise. The Navy revealed that this missile is now operational. Experts then immediately assessed the focus was China.

"The AIM-174B is intended primarily for the Indo-Pacific to counter to developments within the People's Liberation Army Air Force (PLAAF) and naval aviation," Douglas Barrie, a senior fellow for military aerospace at the International Institute for Strategic Studies, wrote in July.

Beijing's development of long-range air-to-air missiles, as well as its broader missile capabilities, have caused concern in Washington.

In the most recent Pentagon report on Chinese military developments, officials noted its work on "beyond-visual-range air-to-air missiles." These weapons could be used to target fighters but also high-value enablers, like air-to-air refueling planes or early warning and control aircraft.

The PL-15 was China's answer to the US AIM-120D Advanced Medium-Range Air-to-Air Missile (AMRAAM). A 2020 Royal United Services Institute report said this missile, a follow-on to the PL-12, "features a miniature AESA seeker head and outranges the US-made AIM-120C/D AMRAAM series."

China has also been working on longer-range options, like the PL-17, that are also pushing the US to develop new capabilities.

Justin Bronk, a RUSI airpower expert, told Business Insider that "China already deploys the PL-15 missile, which has better kinematics than the AIM-120D3, so there is an incentive" to have a missile that "can match or exceed that performance."

That is even more important, he said, considering "the Super Hornet as the primary fighter type still for the US Navy has significantly less impressive kinematic performance itself than the J-20 or J-16," which carry the PL-15 and PL-17.

The AIM-174B gives US Navy carrier air wings a new ability to engage China's air force and naval aviation aircraft at a greater range than its predecessor, potentially closing the gap.

The ship-launched SM-6 missile, also known as the RIM-174, is believed to have a range of up to 230 miles, and it saw combat for the first time last fall against the Houthis. The missile is a three-in-one extended-range weapon for anti-air and anti-surface warfare. It's also able to kill ballistic missiles during the terminal phase of flight.

In an air-to-air role, it brings some of those capabilities to bear in new ways to help the US match newer Chinese weapons.

Bronk said the PL-17 is probably most comparable to the AIM-174B, but the Chinese weapon might have a longer range, in part because of the platforms that are primarily going to be carrying it.

The PL-17 is a rather large missile that appeared on the Chinese J-16 multirole strike fighter during development. More recently, amid indications it was approaching operational status, it was seen on the jet last December. China's J-16 fighter jet is a highly capable fourth-generation aircraft.

The AIM-174B, on the other hand, is carried by the Navy's Super Hornets. Observers have noted that Super Hornets may have trouble carrying the AIM-174B due to its size and weight — the missile is likely five times the weight of the AIM-120D — and that the weapon could impact the jet's top speed and altitude.

That said, the new missile provides valuable reach. In an air combat scenario with China, the AIM-174B could likely be most useful at disrupting China's kill chain, or the process by which a target is identified, targeted, and destroyed and which assets are involved in completing that task. In particular, the missile could target China's airborne early warning and control aircraft that help set up those kill chains.

It also gives American aircraft the ability to target rear assets, like Chinese bombers and intelligence, surveillance, target acquisition, and reconnaissance aircraft.

The air-to-air missile range game is expected to continue though. As the Pentagon noted in its report, China is at work on its air-to-air missiles, and the US is likewise working on next-generation systems like the AIM-260.

Estimates on exactly how the new AIM-174B and China's missiles could perform are based on publicly available data and understanding, and there's a gap in the knowledge of how the missile would actually perform. But even the weapon's existence could be enough to be useful to the US Navy.

"Deterrence," Bronk said, "is about affecting your opponent's calculations, so in some ways, there's inevitably going to be a degree of ambiguity."