2 February 2024

Air-to-air missiles push the performance, payload envelope

Douglas Barrie

Loitering munitions and hypersonic glide vehicles are grabbing most of the attention when it comes to air force modernisation efforts, but that focus risks overlooking enhancements in another area of combat: air-to-air missiles (AAMs).

China and its close aerospace partner Pakistan are among those pursuing upgrades to make their combat aircraft more lethal. Beijing may be near to introducing a very-long-range AAM into service, while Islamabad is upgrading aircraft to carry more of the weapons. Meanwhile, the United States, in addition to developing a longer-range AAM to adjust to a more complex threat environment, is working on increasing by 50% the number of medium-range AAMs it can pack into the main internal bay of the Lockheed Martin F-35 Lightning II combat aircraft.

Big stick

The People’s Liberation Army Air Force (PLAAF) appears to be on the brink of fielding an AAM that could pose a challenge to potential adversaries. The PL-17 (CH-AA-X-12) likely has a range of around 400 kilometres, using a dual-pulse solid rocket motor combined with a lofted trajectory to achieve the distance. The weapon is intended to engage what are sometimes referred to as high-value airborne assets, such as airborne early warning or tanker aircraft.

The PL-17 first publicly emerged in a 2016 picture that showed a very large missile carried by a Shenyang J-16 Flanker N during the development and test programme. Images of a J-16 carrying a PL-17 appeared on social media in December 2023. That missile body was painted blue, indicating it was a training or ground-handling round rather than a live weapon. Its appearance, however, suggests the missile is being introduced into service.

China has not released design details of the weapon or what company is behind it. However, the PL-17 may well feature active and passive radar guidance. The passive sensor would be intended to detect radar emissions from aircraft such as the Boeing E-3D or E-7A Wedgetail airborne early warning aircraft at considerable range. The active seeker would be used for terminal guidance. The PL-17 may combine use of a passive sensor with receiving target-location updates from offboard sensors for much of the missile flight, making it harder for the aircraft being targeted to recognise it was under attack.

Twin track

The PL-17 will complement the PL-15 (CH-AA-10 Abaddon) medium-to-long range AAM in PLAAF service that has also been exported to Pakistan. Islamabad is widening the types of aircraft that can carry the PL-15. The Pakistan Air Force (PAF) already uses an export version of the PL-15 with its Chengdu J-10C Firebird fighter ground-attack aircraft and is now adding the weapon to its Chengdu JF-17 Thunder Block III aircraft. The Block III replaces the JF-17’s mechanically scanned radar with an active electronically scanned array (AESA) to improve targeting capabilities. The China Airborne Missile Academy/Luoyang PL-15 is one of likely three in-service radar-guided AAMs with an AESA rather than a more conventional radar antenna. Japan has fielded an AESA-equipped AAM, while the IISS assesses that the US probably has an AESA on some AIM-120 medium-range AMRAAMs.

The PAF is also adopting a twin-rack-launcher option for the J-10C and JF-17 Block III to increase the number of active radar-guided AAMs each aircraft can carry. Increasing the number of missiles provides, all things being equal, an aircraft with greater combat persistence.

The PLAAF is also increasing weapon load-outs. The service’s Chengdu J-20 heavy fighter can carry four PL-15s in its main weapons bay, but the PL-16 programme aims to pack six into the same space. The PL-16 features a compressed carriage design with folded fins, but it is supposed to deliver the same performance as the bulkier PL-15, probably by using a high-performance dual-pulse motor. The PL-15 likely features an energetic boost-sustain solid-propellant motor.

Lightning load

China’s missile developments have prompted the US to pursue upgrades to its air-to-air missile capability. The F-35 was designed to carry up to four AIM-120s internally in its main bay. The US, through a programme known as ‘Sidekick’, is working on enhancing that to six AIM-120s on the F-35A flown by the air force and the US Navy’s F-35C. The Pentagon intended the F-35 primarily as a ground-attack aircraft, complementing the US Air Force’s air superiority fighter, the Lockheed Martin F-22 Raptor. Still, the US has increasingly been pushing to bolster its air-to-air capacity too.

The US is also working on the Lockheed Martin AIM-260 Joint Advanced Tactical Missile as an eventual replacement for the AIM-120. The US has closely guarded performance goals for the AIM-260, which has been in development since around 2017, but its requirement was informed by the capabilities of the Chinese PL-15, including its projected 200 km range.

The move–countermove cycle now playing out between the US and China in the AAM realm is emerging as another clear example of how Beijing has supplanted Moscow as the principal threat driver Washington worries about.

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