The PL-21 (Thunderbolt-21) missile is considered to be an active radar-guided ultra-long-range air -to - air missile independently developed by China . It can be used to kill enemy early warning aircraft and aerial tankers at long distances , and fundamentally weaken the opponent’s air combat system. And even the capabilities of the entire combat system. In the early years, some air-to-air missile development pedigrees circulated on forums showed the PL-21 model. The missile has wedge-shaped inlets on both sides, so it can be determined that it uses a ramjet engine . However, no similar missiles have been exposed yet. In 2016, a group of photos of an unknown missile mounted on the F-16 took off on the Internet. The missile is estimated to be close to or more than 6 meters in length. It is judged from the appearance that it is a long-range air-to-air missile driven by a rocket engine . Therefore, some media and netizens believe that this model is the rumored PL-21. As of 2021, Chinese officials have not disclosed any PL-21-related information, nor had it officially confirmed the existence of the number. Some sources claim the PL-20 and PL-21 are the same missile, though the provenance of the two designators remains unclear. The Chinese Military Aviation website reported that a new long-range active radar homing AAM is under development, based on the PL-12 technology. The new PL-21, is said to be similar to the British Meteror Beyond Visual Range Air-to-Air Missile (BVRAAM). Meteor is a new concept in air to air weapons, employing advanced air breathing motor technology and state of the art electronics to provide optimum performance against increasingly complex threats. Conventional rocket motor powered missiles rely upon an initial boost phase to achieve the high speed required followed by a 'coast' phase to intercept the target. Latest generation, highly manoeuvrable aircraft, are able to out run conventional missiles at the extremes of their range. The air breathing motor proposed for Meteor provides sustained power, following the initial boost, to chase and destroy the target.

PL-21（“霹雳”（Thunderbolt）-21）导弹被认为是中国自主研发的主动雷达制导超远程空空导弹。它可以用来远程摧毁敌人的预警机和空中加油机，从根本上削弱对手的空战系统,，甚至整个作战系统的能力。早些年，一些在论坛上流传的空空导弹发展谱系显示了PL-21模型。导弹两侧都有楔形进气口，因此可以确定它使用的是冲压发动机。然而，目前还没有发现类似的导弹。2016年，一组起飞时的歼-16配备未知导弹的照片在互联网上出现。据估计，该导弹的长度接近或超过6米。从外观来看，这是一种由火箭发动机驱动的远程空空导弹。因此，一些媒体和网民认为这种型号就是传说中的PL-21。截至2021年，中国官方尚未公布任何与PL-21——相关的信息，也没有正式证实该编号的存在。一些消息人士称，PL-20和PL-21是同一枚导弹，但这两个代号的来源尚不清楚。中国军用航空网站报道，一种基于PL-12技术的新型远程主动雷达寻的空空导弹正在研制中。新的PL-21据说与英国“流星”（Meteror）超视距空空导弹（BVRAAM）相似。“流星”是空对空武器中的一个新概念，它采用先进的吸气式冲压发动机技术和最先进的电子技术，在应对日益复杂的威胁时提供最佳性能。传统的火箭发动机动力导弹依靠初始助推阶段来达到所需的高速，然后是“滑行”阶段来拦截目标。最新一代，高度机动的飞机，能够在常规导弹射程的极限上逃脱。为“流星”设计的吸气式发动机在初始助推后提供持续的动力，以追逐和摧毁目标。

 

METEOR is a fast and highly manuverable Beyond Visual Range air-to-air weapon. Meteor uses a 'stealthy launch' technique, giving the enemy less time to take evasive action and it can engage multiple targets simultaneously - no matter what the weather conditions. METEOR provides the largest No Escape Zone of any air-to-air weapon, resulting in a long stand-off range and high kill probability to ensure air superiority and pilot survivability. Guidance is provided by an active radar seeker benefiting from enhanced technologies drawn from the MBDA Aster and Mica missile programs. METEOR is capable of engaging air targets autonomously by night or day, in all weather and in severe electronic warfare environments. The BVRAAM is equipped with both a proximity and impact fuse to ensure total target destruction in all circumstances.

“流星”（Meteor）是一种快速且高度机动的的超视距空对空武器。“流星”采用了“隐形发射”技术，让敌人有更少的时间采取规避行动，而且它可以同时攻击多个目标——无论天气条件如何。“流星”提供了所有空对空武器中最大的无逃生区，从而实现了较远的防区外射程和较高的杀伤概率，以确保空中优势和飞行员生存能力。制导由有源雷达导引头提供，该导引头受益于欧洲导弹集团紫菀（MBDA Aster）防空导弹r和“米卡”（Mica）导弹项目的增强技术。“流星”能够在夜间或白天、全天候和恶劣的电子战环境中自主攻击空中目标。BVRAAM配备了近炸引信和碰炸引信，以确保在所有情况下彻底摧毁目标。

 

The PL-12 features an active radar seeker and an integrated ramjet/solid rocket motor with a entral air inlet. As with the Russian R-27/AA-10, the PL-21 features 4 small stabilzing fins behind the active radar seeker. Two-way datalink antennas may be installed in the tail section for mid-course correction. The effective range of PL-21 is expected to be greater than 100km. The missile might be carried by the new J-11B and J-20 fighters for long-range interception. Chinese Military Aviation reports that the first ground launch test took place in March 2010, with development projected to be completed by 2012. Such a two year development cycle seems rather brief, considering the five years that elapsed between the first test flights of the METEOR in 2005 and first deliveries in 2012.

PL-12具有一个主动雷达导引头和一个带有内部进气口的集成冲压发动机/固体火箭发动机。与俄罗斯的R-27/AA-10一样，PL-21在主动雷达导引头后面有四个小稳定鳍。双向数据链天线可以安装在尾部，用于中途校正。PL-21的有效射程预计将大于100公里。该导弹可能由新型J-11B和J-20战斗机携带，用于远程拦截。中国军用航空报道称，2010年3月进行了首次地面发射试验，预计2012年完成开发。考虑到2005年“流星”的首次试飞和2012年的首次交付之间的五年时间，这样一个两年的开发周期似乎相当短暂。

 

The US media said that China's new ultra-long-range air-to-air missile codenamed "PL-21", which is 5 meters long, uses a high-thrust ballistic and double-pulse solid rocket engine, uses active radar and infrared imaging dual-mode guidance, and is guided by a two-way data link. Ballistics can be launched by mounting on the J-16 and J-20. The US Air Force believes that the air-to-air missile has a range of 400 kilometers and can pose a huge threat to US military early warning aircraft, electronic warplanes and other special aircraft. China should not underestimate the new long-range air-to-air missile being developed by the US Air Force, Chinese military experts said on Wednesday after the development of the new US weapon was revealed. The US Air Force is working with arms manufacturer Lockheed Martin and other branches of its military to develop a new long-range air-to-air missile called the AIM-260, which is expected to enter military service by 2022, US media outlet the National Interest reported on 24 June 2019. The motivation behind such a development is to counter China's top long-range air-to-air missile, the PL-15, which was made public in 2016, the National Interest reported, quoting US Air Force Weapons Program Executive Officer Anthony Genatempo.

美国媒体称，中国新型超远程空空导弹代号为“PL-21”，长5米，采用大推力冲压和双脉冲固体火箭发动机，采用主动雷达和红外成像双模制导，采用双向数据链路制导。导弹可以安装在J-16和J-20上发射。美国空军认为，空空导弹的射程为400公里，可以对美军预警机、电子战机等特种飞机构成巨大威胁。中国军事专家周三在美国新武器的研发被披露后表示，中国不应低估美国空军正在研发的新型远程空空导弹。美国媒体于2019年6月24日报道称，美国空军正在与武器制造商洛克希德·马丁公司及其军队的其他分支合作，开发一种名为AIM-260的新型远程空对空导弹，该导弹预计将在2022年前服役。《国家利益报》援引美国空军武器项目执行官安东尼·吉纳坦波的话说，这种发展背后的动机是对抗中国最顶级的远程空空导弹PL-15，该导弹于2016年公开。

 

Having a maximum range of about 160 kilometers, the US' current air-to-air missile the AIM-120 is apparently inferior to China's PL-15, judging by the US military's decision to create a new weapon, the National Interest report said. The PL-15 is equipped with active electronically scanned array radar and is thought to have a range of about 200 kilometers. China's top stealth fighter jet J-20 displayed its weapons including what analysts said was the PL-15 missile at Airshow China in Zhuhai, South China's Guangdong Province in November 2018. China is also developing a new missile known as the PL-21, which could reach targets 300 kilometers away, the Business Insider report said. Some Chinese military observers said the US, once a forerunner in weapon development, is now chasing China, and the new AIM-260 could be a copycat of the PL-15 in terms of applied technologies.

《国家利益》报告称，美国目前的空对空导弹AIM-120的最大射程约为160公里，从美军制造新武器的决定来看，显然不如中国的PL-15。PL-15配备有源电子扫描相控阵雷达，被认为射程约为200公里。中国顶级隐形战斗机J-20在2018年11月于中国南方广东省珠海举行的中国航展上展示了其武器，包括分析人士所说的PL-15导弹。中国还在开发一种名为PL-21的新型导弹，该导弹商业内幕报道称，它可以到达300公里外的目标。一些中国军事观察人士表示，美国曾经是武器开发的先行者，现在正在追赶中国，而新的AIM-260在应用技术上可能是PL-15的山寨版。

 

An anonymous Chinese military expert, however, told the Global Times 26 June 2019 that China should not underestimate the AIM-260 due to its late-mover advantages. The expert predicted that the US missile could use revolutionary technologies to boost range significantly without making it significantly larger, and these technologies will in return bring pressure to China's air-to-air missile development. US media used to hype that China made copycat weapons, which makes little sense as weapon designing tends to converge due to similar combat requirements, said the expert, suggesting the US is probably not trying to copy China's weapons.

然而，一位匿名的中国军事专家在2019年6月26日告诉《环球时报》，中国不应低估AIM-260的后发优势。这位专家预测，美国导弹可以使用革命性的技术来显着增加射程，而不会使其尺寸明显变大，而这些技术反过来会给中国的空空导弹发展带来压力。这位专家说，美国媒体过去常常大肆宣传中国制造的仿制武器，这毫无意义，因为由于类似的作战要求，武器设计往往趋于趋同，暗示美国可能没有试图复制中国的武器。

 

From the picture published in the media, both sides of the PL-21 missile appeared inlets, suggesting that PL-21 uses a ramjet. The air-to-air missile system's main driving force is normally solid rocket motors. The advantages are simple structure, compact size, reliable operation, low cost, wide applicable height and speed range, and convenient maintenance. The disadvantages are low specific impulse, short working time, difficult thrust adjustment, and it is difficult to switch on and off multiple times. Solid rocket In order to increase the working time of the engine and increase the effective range of the missile, the single-chamber double-thrust method is used for the engine to generate two kinds of thrust in a fuel chamber through different charge designs or two kinds of grains with different burning speeds, that is, the take-off phase. The high thrust of high-speed combustion and the small thrust of low-speed combustion in the cruise section, but this increases the complexity and cost of the engine, especially the solid rocket motor needs its own oxidizer and fuel, so as the range of the missile increases, its weight and volume also increase.

从媒体公布的图片来看，PL-21导弹的两侧都出现了进气口，表明PL-21使用了冲压发动机。空空导弹系统的主要驱动力通常是固体火箭发动机。其优点是结构简单、体积小、运行可靠、成本低、适用高度和速度范围广、维护方便。缺点是比冲低，工作时间短，推力调节困难，难以多次开关。固体火箭为了增加发动机的工作时间，增加导弹的有效射程，发动机采用单室双推力的方法，通过不同的装药设计在燃料室内产生两种推力，或两种不同燃烧速度的颗粒，即起飞阶段。巡航段高速燃烧的大推力和低速燃烧的小推力，但这增加了发动机的复杂性和成本，尤其是固体火箭发动机需要自己的氧化剂和燃料，因此随着导弹射程的增加，其重量和体积也会增加。

 

For example, the American AIM-54 air-to-air missile weighs more than 400 kilograms, which is almost twice the weight of the AIM-7M Sparrow air-to-air missile of the same period. The heavier weight and volume of AIM-54 not only its own maneuverability, but also reduces the fighter aircraft. Therefore, the long-range air-to-air missile needs a new power system to achieve the unity of range and maneuverability. This is the ramjet, which is not enough with the solid rocket motor. The ramjet is an air-breathing engine. Oxygen is used as a combustion-supporting agent to mix fuel with the fuel carried by the missile itself to form thrust. Since there is no need to carry a combustion-supporting agent, compared with ordinary aspirated engines, ramjets use the static pressure generated by the missile's high-speed flight, thus eliminating the need for conventional Compressor required for jet engineTherefore, it has the characteristics of simple structure, low quality and low cost. Therefore, the missile with a ramjet can effectively control the volume and weight.

例如，美国AIM-54空空导弹重量超过400公斤，几乎是同期AIM-7M“麻雀”空空导弹重量的两倍。AIM-54较重的重量和体积不仅降低了自身的机动性，而且也降低了战斗机的。因此，远程空空导弹需要新的动力系统来实现射程和机动性的统一。这就是冲压式喷气发动机，使用固体火箭发动机来说是不够的。冲压式喷气发动机是一种吸气式发动机。氧气作为助燃剂，将燃料与导弹自身携带的燃料混合，形成推力。由于不需要携带助燃剂，与普通吸气式发动机相比，冲压式喷气发动机利用导弹高速飞行产生的静压，从而省去了喷气发动机所需的常规空气压缩机，具有结构简单、质量低、成本低等特点。因此，带有冲压发动机的导弹可以有效地控制体积和重量。

 

But the ramjet also has its own shortcomings; it cannot generate thrust when it is stationary, so it cannot take off by itself. The thrust system, in addition, has low thrust at low speeds, is not suitable for low-speed flight, and has high fuel consumption. In addition, it is more sensitive to changes in flight status. Changes in flight altitude, angle of attack, and speed will affect the performance and status of the ramjet engine. Based on the above shortcomings, an integral ramjet has emerged, which is to integrate the solid rocket booster and the ramjet, and use the combustion shell of the solid rocket booster as the combustion chamber of the ramjet to reduce the weight and volume of the ramjet. There are two types of ramjets used for air-to-air missiles, one is a solid rocket ramjet and the other is a liquid fuel ramjet. The former is the familiar meteor air-to-air missile. It is equipped with a gas generator using oxygen-poor solid propellant.

但是冲压发动机也有自己的缺点；它静止时不能产生推力，因此不能自行起飞。此外，推力系统在低速时推力较低，不适合低速飞行，并且燃油消耗较高。此外，它对飞行状态的变化更为敏感。飞行高度、迎角和速度的变化将影响冲压发动机的性能和状态。基于上述缺点，出现了一种整体式冲压发动机，即将固体火箭助推器和冲压发动机结合起来，用固体火箭助推器的燃烧壳体作为冲压发动机的燃烧室，以减轻冲压发动机的重量和体积。用于空空导弹的冲压发动机有两种，一种是固体火箭冲压发动机，另一种是液体燃料冲压发动机。前者是我们熟悉的流星空对空导弹。它配备了使用贫氧固体推进剂的燃气发生器。

 

Using the oxygen-lean gas produced by the generator as fuel to supply the ramjet fuel chamber for secondary fuel, while the liquid fuel ramjet uses ordinary aviation kerosene as fuel, and the advanced mid-range air-to-air missile that competed with Meteor back then was The use of liquid ramjet has its own advantages in terms of the performance characteristics of the two. The solid rocket motor has the characteristics of simple structure and high reliability, but lower energy, while the liquid ramjet has higher energy, but the structure is more complex and the reliability is low.

使用发生器产生的贫氧气体作为燃料，为冲压发动机燃料室提供二次燃料，而液体燃料冲压发动机使用普通航空煤油作为燃料，而当时与“流星”竞争的先进中程空空导弹则是液体冲压发动机，从两者的性能特点来看，液体冲压发动机有其自身的优势。固体火箭发动机具有结构简单、可靠性高、能量低的特点，而液体冲压发动机具有能量高、结构复杂、可靠性低的特点。

 

The Pili-21 missile adopts the normal aerodynamic layout, that is, the wings are in the front and the rudder surface is behind. The advantage of this layout is that the rudder surface is farther from the center of gravity of the missile, so a smaller area of the rudder surface can be larger. Torque, thereby reducing the volume and weight of the missile. At the same time, because the wings are fixed, the washing effect on the rear rudder surface is small, and the aerodynamic performance is better. The disadvantage is that the missile’s engine is generally located in the middle and rear part, so The installation of the steering gear and the control system is limited. In addition, the lift generated by the wings is sometimes opposite to the lift generated by the rudder surface. The responsivness of the missile is poor, especially when the weight and volume of the missile itself are relatively large, so the Thunderbolt-21 A set of fixed winglets are added to the warhead, whose role is to improve the stability and maneuverability of the missile's full ballistic flight. 

Pili-21导弹采用正常气动布局，即弹翼在前，舵面在后。这种布局的好处是舵面离导弹重心较远，所以，在方向舵表面的一个更小的面积就会产生更大扭转力，从而减少导弹的体积和重量。同时，由于弹翼固定，对后舵面的冲刷作用小，气动性能更好。缺点是导弹的发动机一般位于中后部，因此舵机和控制系统的安装受到限制。此外，弹翼产生的升力有时与舵面产生的升力相反。导弹的响应性很差，尤其是当导弹本身的重量和体积相对较大时，因此在弹头上增加了一组固定小翼，其作用是提高导弹全弹道飞行的稳定性和机动性。

 

The advanced engine and reliable aerodynamic layout only solve the problem of the missile's flight distance. In order to effectively attack the target, A sophisticated guidance system is also needed. Our country has mastered the technology of the composite guidance system for medium-range active radar-guided air-to-air missiles. Therefore, the guidance system of the Pili-21 air-to-air missile will definitely develop from this system. Subsonic speed is used to ensure the stability of the fuel. During this process, the temperature in the fuel chamber rises sharply due to aerodynamic work. Therefore, the speed of the ramjet generally does not exceed Mach 4, so the missile needs to fly for nearly 2 minutes to enter the terminal guidance. Stealth aircraft is quite unfavorable, so I think it is necessary to transplant the composite terminal guidance system technology developed for the Pili-21 for the Pili-12B air-to-air missile, which is to add a passive guidance system. 

先进的发动机和可靠的气动布局只能解决导弹的飞行距离问题。为了有效地攻击目标，还需要一个复杂的制导系统。我国已经掌握了中程主动雷达制导空空导弹复合制导系统技术。因此，Pili-21空对空导弹的制导系统肯定会从这个系统发展而来。亚音速用于确保燃油的稳定性。在这个过程中，由于空气动力的作用，燃料室内的温度急剧上升。因此，冲压发动机的速度一般不超过4马赫，因此导弹需要飞行近2分钟才能进入末制导。隐形飞机是相当不利的，所以我认为有必要移植为Pili-12b空对空导弹开发的复合终端制导系统技术用于Pili-21，即增加一个被动制导系统。

 

The passive guidance system uses the opponent’s radar signal to guide. The signal is only reduced in one way and the radar power of the early warning aircraft is larger, so the detection range of the terminal guidance system can be expanded, thereby reducing the dependence on fighter guidance. 

被动制导系统利用对手的雷达信号进行引导。信号仅以一种方式减少，预警机的雷达功率更大，因此可以扩大末制导系统的探测范围，从而减少对战斗机制导的依赖。

 

The development of ramjet engines in China started early. Since the 1960s, it has started to develop the supersonic anti-ship missile Haiying-3 with ramjet engines . Since the 1990s, it has broken through the integrated ramjet technology and successfully developed integrated liquids. Ramjet and integral solid rocket ramjet, then which one is used by Pili-21? From the characteristics of the two engines, I think it is more likely to be an integral solid rocket motor. I said that solid rocket ramjet is The high temperature and rich combustion gas produced by the combustion of the oxygen-lean propellant in the gas generator is used as a powerful fire source for the ram afterburner, so the engine can work under a wide air-fuel ratio. When the external atmospheric conditions and flight attitude change, it will not cause flameout, so that the missile can work at a larger angle of attack, which increases the mobility of the missile. This is very valuable for air-to-air missiles that often need to change their flight trajectory. For the shortcomings of insufficient energy of solid rocket ramjets, the emergence of fuel-efficient high-metal content propellants makes up for this shortcoming, which is why solid rocket ramming is used The main reason why the engine's meteor missile can win the competition is that the air intake of the Pili-21 missile is located under the side of the projectile on both sides, and the air intake is swept back to increase the area of ??the air intake. The purpose is to improve the ability of the missile to pre-compress the airflow with the missile body under the condition of a large angle of attack, thereby reducing the airflow turbulence in the intake duct, improving the intake efficiency, and avoiding the change of the ramjet working state and flameout caused by the maneuvering of the missile. 

中国冲压喷气发动机的发展起步较早。自20世纪60年代以来，中国开始研制超音速反舰导弹海鹰三号冲压发动机。自20世纪90年代以来，突破了一体化冲压发动机技术，成功研制出一体化液体冲压发动机和整体式固体火箭冲压发动机，那么Pili-21用的是哪一种？从两款发动机的特点来看，我认为它更有可能是一体式固体火箭发动机。我说的固体火箭冲压发动机是将贫氧推进剂在气体发生器中燃烧产生的高温富燃烧气体作为冲压加力燃烧室的强大火源，因此发动机可以在较大的空气—燃料比下工作。当外界大气条件和飞行姿态发生变化时，不会引起熄火，使导弹可以在更大的迎角下工作，增加了导弹的机动性。这对于经常需要改变飞行轨迹的空空导弹来说非常有价值。对于固体火箭冲压发动机能量不足的缺点，节油的高金属含量推进剂的出现弥补了这一缺点，这也是为什么使用固体火箭冲压发动机的流星导弹能够赢得竞争的主要原因。Pili-21导弹的进气口位于弹体两侧侧面下方，进气口后掠以增加进气口面积。目的是提高导弹在大攻角的条件下与导弹体预压缩气流的能力，从而减少进气道内的气流湍流，提高进气效率，避免导弹机动引起的冲压机工作状态的改变和熄火。

 

The successful development of the Pili-21 long-range air-to-air missile has greatly improved China’s air defense capabilities. In particular, the Chinese Air Force has the ability to attack key system nodes such as the other’s early warning aircraft , which can fundamentally weaken the opponent’s air combat system and even the entire combat system. Ability. According to relevant data, the foreign early warning aircraft with the strongest detection capability is the E-3A early warning aircraft after the improvement of the radar upgrade (RSIP) plan . It claims to provide a detection capability of 550 kilometers for targets with RCS=0.5. If the RCS=0.05 of the overseas data J-20 is calculated, then the E-3ARSIP early warning aircraft has a detection capability of about 200 kilometers, so that the J-20 can already intercept it with the Thunderbolt-21, although there is news that E-3A’s improvements also include the addition of electronic support, missile approach warning, jammer launching and other systems. However, in the face of rapidly approaching air-to-air missiles, it may still be necessary to adopt a combination of route maneuvering and interference release. At the same time, it may also take radar Measures such as cutting off the high voltage, reducing electromagnetic signals or even shutting down will inevitably lose the ability to master the air situation in the theater, and lose the command, guidance and support of external air situation information, even stealth fighters like the F-22 cannot be displayed. With all its combat capabilities, if it cooperates with ballistic missiles and cruise missiles to attack its AWACS base, it will put the other AWACS in an embarrassing situation of "cannot fly and fall." The early warning and the joint combat system formed with the F-22 is the most powerful air combat system. It can be said that the maintenance of US theater air combat is the basis of joint combat capabilities. If it can threaten early warning aircraft, it can be fundamentally weakened from this. The air combat capability of the opposing theater. 

Pili-21远程空空导弹的研制成功，极大地提高了中国的防空能力。尤其是中国空军具备攻击对方预警机等关键系统节点的能力，可以从根本上削弱对手的空战系统乃至整个作战系统，能力。相关资料显示，国外探测能力最强的预警机是雷达升级（RSIP）计划改进后的E-3A预警机。它声称可以为RCS=0.5的目标提供550公里的探测能力。如果计算海外数据J-20的RCS=0.05，那么E-3ARSIP预警机的探测能力约为200公里，这样J-20就已经可以用霹雳-21拦截了。虽然有有消息称，E-3A的改进还包括增加电子支援、导弹接近警告、干扰机发射等系统。但是，面对快速逼近的空空导弹，可能仍需要采用路线机动和干扰释放相结合的方式。同时，也可能对雷达采取切断高压、减少电磁信号甚至关机等措施，势必会失去对战区空中形势的掌握能力，失去对外指挥、引导和支援的能力。空情信息，连F-22这样的隐身战机也无法显示。Pili-21凭借其全部的作战能力，如果配合弹道导弹和巡航导弹攻击其预警机基地，将使其他预警机陷入“飞不起、落不下”的尴尬境地。预警机与F-22形成的预警和联合作战系统是最强大的空战系统，可以说，美军战区空战的维持是联合作战能力的基础。如果能威胁到预警机，就可以从根本上削弱它，对方战区的空战能力。

 

The Pili-21 can also effectively intercept cruise missiles . The main reason why the United States developed AIM-54 was to intercept the former Soviet Union’s anti-ship missiles. Against the background of flat seas, ballistic anti-ship missiles have become excellent targets for AIM-54. For our country, if the other party launches cruise missiles from the first island chain, the cruise missiles need to be on the sea. Flying for nearly an hour, then at this time, using the high-precision airborne AESA fire control radar, cruise missiles can be intercepted at a relatively long distance, and the depth of defense can be extended from the outside, thereby extending time and space for the inner defense. Another point is to take advantage of the stealth advantage of the J-20 and the long-range interception capability of the Pili-21. It can penetrate around the first island chain to intercept bombers carrying cruise missiles, because one bomber can carry more than 10 In this way, shooting down a bomber is equivalent to intercepting more cruise missiles. At the same time, it can also force the other party to launch cruise missiles at a greater distance. This increases the exposure probability of cruise missiles, thereby increasing our interception time and effectiveness. If the J-20 provides the material basis for the Chinese Air Force to fight out, then the Pili-21 converts this ability into combat effectiveness, especially with the ability to strike key information nodes such as early warning aircraft. The ability to fundamentally weaken the opponent’s combat capability is critical in modern air combat and even modern high-tech local wars.

Pili-21还可以有效拦截巡航导弹。美国研制AIM-54的主要原因是为了拦截前苏联的反舰导弹。在平坦的海域背景下，弹道反舰导弹成为AIM-54的绝佳目标。对于我国来说，如果对方从第一岛链发射巡航导弹，巡航导弹需要在海上，飞行了近一个小时，那么此时，利用高精度机载AESA火控雷达，可以在比较远的距离拦截巡航导弹，从外部延伸防御纵深，从而延长时间和空间用于内部防御。还有一点就是利用歼20的隐身优势和Pili-21的远程拦截能力。它可以穿透第一岛链周围拦截携带巡航导弹的轰炸机，因为一架轰炸机可以携带超过10枚这样的巡航导弹，击落一架轰炸机就等于拦截了更多的巡航导弹。同时，也可以迫使对方在更远的距离发射巡航导弹。这增加了巡航导弹的暴露概率，从而增加了我们的拦截时间和效率。如果说歼20为中国空军提供了实战的物质基础，那么Pili-21将这种能力转化为战斗力，尤其是具备打击预警机等关键信息节点的能力。从根本上削弱对手作战能力的能力在现代空战乃至现代高科技局部战争中至关重要。