PL-4 (PL = Pi Li, 霹雳, meaning thunderbolt) is the first Chinese Semi-active radar homing (SARH) air-to-air missile (AAM), and it has an anti-radar derivative, which is also the first Chinese anti-radiation missile. However, neither entered Chinese service en masse, and both programs were eventually cancelled after very limited numbers had been built for evaluation purposes.
PL-4（PL = Pi Li，霹雳，意为雷电）是中国第一枚半主动雷达制导（SARH）空对空导弹（AAM），它有反雷达的衍生型号，也是中国第一枚反辐射导弹。但是，它们都没有大规模进入中国服役，在为评估目的制造了非常有限的数量之后，这两个项目最终都被取消。
PL-4 program began in March 1966, as the primary weapon that would be used by the proposed Chengdu J-9. The primary contractor was the 612th Research Institute of Chinese Aeronautical Ministry, more commonly known as the Luoyang Electro-Optics Technology Development Center (洛阳光电技术发展中心) nowadays, which became the China Air-to-Air Guided Missile Research Institute (中国空空导弹研究院) in 2002. The primary subcontractor for the propulsion was the 331st Factory, which would later become Zhuzhou Aero-engine Factory (株洲航空发动机厂). PL-4 is based on the American AIM-7D Sparrow IIIa AAM North Vietnam provided to China, after obtaining samples from downed American fighters during Vietnam War. However, barely two month after the program begun, Cultural Revolution started and due to this political turmoil, PL-4 program was disrupted to a complete stop, and it would not be until more than a decade later, well after the end of Cultural Revolution, would the program restart again.
The rocket motor of PL-4 is designated as FG101, and is shared by another anti-radar derivative named Fenglei-7 (风雷7号). The revival of PL-4 was partially due to the decision to develop the anti-radar derivative in January 1979. The designer of the rocket motor was Harbin Ship Engineering Academy (哈尔滨船舶工程学院), the predecessor of Harbin Engineering University, 349th Factory was tasked to manufacture the propellant, 845th Factory was tasked for ground test, and 331st Factory was tasked for final integration. During the propulsion development, the contractor and subcontractors developed new manufacturing techniques, including improvements in installation, new rivet pins, graphite exhaust nozzle, and tolerance. A brand new heat processing method for integrated spin forming was adopted to achieve the high precision engine components, and this was achieved via the use of a special spin forming machinery set specially developed by the Beijing Nonferrous Metal Research Academy (北京有色金属研究院). Once the bottleneck of propulsion has been overcame, both programs went forward with ease, and but the conclusion of political turmoil, namely, the end of Cultural Revolution was an even more crucial contribution in the later development.
With the development of the engine completed, all ground tests were subsequently completed in November 1980. The program proceeded to the second stage, starting in July 1981. Borrowing from the former-Soviet practice of developing two seekers for the same missile, which China considered a good idea, it was decided to develop two versions of PL-4, the SARH guided PL-4A (霹雳4甲), and the IR guided PL-4B (霹雳4乙). In addition to the original Chengdu J-9, PL-4 was planned to equip other Chinese aircraft as well.
By 1984, the first batch produced and ground maintenance equipment were sent to Chinese military for evaluation. Although the missile met its original requirement, th performance was not satisfactory because the requirement itself dating almost two decades ago was obsolete itself. Another factor that led to the eventual cancellation of PL-4 was that during the Sino-USA cooperation in the 1980s, China and US made a deal named project Peace Pearl, where Chinese Shenyang J-8 would be upgraded with American radars. Part of the deal included Chinese purchase of advanced version of AIM-7 Sparrow, making the PL-4 unnecessary. Additionally, China and Italy were also negotiating a deal on the Chinese purchase of Italian Aspide missile, another advanced version of AIM-7, which successfully completed in 1986, and this had further strengthened the Chinese decision to cancel the PL-4 program, which was finalized in 1985, terminating both PL-4A and PL-4B.
IR guided PL-4B (霹雳4乙) is the second member of PL-4 series, developed soon after PL-4A, but it actually entered Chinese service for evaluations earlier than the SARH guided PL-4A. The IR seeker borrowed directly and heavily from PL-2 series AAM, and adaptation of matured technology was the primary reason why its initial completion was faster than its SARH guided counterpart. Another advantage of PL-4B was that due to its IR guidance, the logistic was much simpler than PL-4A, which meant that the cost was also reduced accordingly. Furthermore, unlike PL-4A, most of the ground maintenance equipment of PL-4B was same or similar to that of other IR guided AAM in Chinese inventory, thus further simplifying logistics and reducing costs.
Despite its advantage, it was revealed during evaluation that the performance of PL-4B was not satisfactory. One of the primary drawback was that the 8 km range of PL-4B was simply too short, and offers no obvious advantage to other IR guided AAM China had. Coupled with factors listed above for PL-4A, PL-4B met with the same fate, ending being cancelled in 1985 along with PL-4A.
尽管具有优势，但在评估过程中发现PL-4B的性能并不令人满意。 主要缺点之一是PL-4B的8公里射程太短了，对其他IR导引的AAM中国没有明显的优势。 再加上上面列出的关于PL-4A的因素，PL-4B遇到了同样的命运，并于1985年与PL-4A一起被取消。
Fenglei-7 (风雷7号) missile is first Chinese anti-radar missile (ARM), with Fenglei (or Feng Lei) meaning Wind (and) Storm. The abbreviated form of Fenglei-7 is FL-7, which should not be confused with the Chinese supersonic anti-ship missile FL-7, abbreviation for Feilong (Fei Long, 飞龙) meaning Flying Dragon. Fenglei-7 is an anti-radiation missile (ARM) derivative of PL-4 missile, sharing the same rocket motor, just like the way AGM-45 Shrike sharing the same rocket motor with AIM-7 Sparrow. In fact, PL-4 was mostly based on AIM-7 while Fenglei was mostly based on AGM-45. Just like AIM-7, complete samples of AGM-45 and AGM-78 Standard ARM missiles were also provided to China by North Vietnam during the Vietnam War, mostly from downed American aircraft, but some were unexploded rounds fired at anti-aircraft sites. Experience gained from Chinese air defense troops sent to help North Vietnam during Vietnam War made Chinese high command realized the need of ARM, but sample of AGM-78 were simply too rare, and the Chinese industrial capability was simply not adequate enough to reverse engineer something as advanced as AGM-78. As a result, China decided to develop its own ARM based on AGM-45, incorporating whatever technologies it could gain from AGM-78, based on the available Chinese industrial capability at the time. However, Fenglei-7 had a rocky start in comparison to PL-4. As with its American counterpart, China also decided to use the same rocket motor for both the AAM and ARM. Cultural Revolution delayed the program, and it was not until the general headquarter of the People's Liberation Army Air Force made requests to the Commission for Science, Technology and Industry for National Defense (COSTIND) twice, once in 1976 and the other in 1977, did the program finally gathers momentum. Form June 27 to June 28, 1976, under the direction of the 8th Bureau of the Machinery Ministry of the Ministry of National Defense of the People's Republic of China, the National Defense Industry Bureau of Heilongjiang held a conference on the planning of Fenglei-7. Different tasks were assigned to various establishments and factories at this two-day conference. Harbin Ship Engineering Academy (HSEA, 哈尔滨船舶工程学院), the predecessor of Harbin Engineering University was tasked with the design of airframe, control surfaces and engine, and the 349th Factory was tasked with manufacturing these parts, as well as the development of propellant. HESA and Harbin Industrial University were tasked to design the fuse, seeker and flight control system while 254th Factory was tasked to manufacture these parts. On October 28, 1978, Central Military Commission of the People's Republic of China (CMC) formally gave its concurrence to develop Fenglei-7 ARM based on AGM-45, and additional assignment were given to the 349th factory and 254th Factory: the former was tasked to develop ground support equipment while the latter was tasked to develop the test equipment of the part it would manufacture.
风雷7号（Fenglei-7）导弹是中国第一种反雷达导弹（ARM），“风雷（Feng Lei）”的意思是风（和）风暴。凤雷7的缩写形式是FL-7，不应与中国的超音速反舰导弹FL-7混淆，后者是飞龙（Feilong，飞龙）的缩写，意思是飞龙。风雷7是PL-4导弹的反辐射导弹（ARM）衍生型号，共享同一种火箭发动机，就像AGM-45“百舌鸟”与AIM-7“麻雀”共享同一种火箭发动机一样。实际上，PL-4主要基于AIM-7，而“风雷”主要基于AGM-45。就像AIM-7一样，越南战争期间北越也向中国提供了AGM-45和AGM-78标准ARM导弹的完整样本，其中大部分来自被击落的美国飞机，但有一些未爆炸弹是在高空发射的。越南战争期间从中国派来防空部队帮助北越的经验使中国的高级指挥官意识到需要ARM，但是AGM-78的样本实在太少了，而且中国的工业能力不足以对某些东西进行逆向工程与AGM-78一样先进。结果，中国决定根据当时的中国工业能力，开发自己的基于AGM-45的ARM，并结合其可以从AGM-78获得的任何技术。但是，与PL-4相比，风雷7号（Fenglei-7）的起步很艰难。与美国同行一样，中国也决定AAM和ARM使用相同的火箭发动机。文化大革命推迟了该计划，直到人民解放军空军总司令部两次向国防科学技术工业委员会（COSTIND）发出请求，一次是在1976年，另一次是在1977年。该计划终于获得了动力。1976年6月27日至6月28日，在中华人民共和国国防部机械部第八局的指导下，黑龙江省国防工业局召开了风雷7号规划会议。在为期两天的会议上，将不同的任务分配给各个机构和工厂。哈尔滨工程大学的前身哈尔滨船舶工程学院（HSEA，Harbin Ship Engineering Academy）负责弹体，操纵面和发动机的设计，第349工厂的任务是制造这些零件以及开发推进剂。 HESA和哈尔滨工业大学的任务是设计保险丝，导引头和飞行控制系统，而第254工厂的任务是制造这些零件。1978年10月28日，中华人民共和国中央军事委员会正式同意开发基于AGM-45的风雷7号ARM，并分别分配给第349工厂和第254工厂。前者负责开发地面支持设备，而后者则负责开发将要制造的零件的测试设备。
In March 1980, two prototypes with FG101 rocket motor successfully completed its test flight at the Base # 31 of People's Liberation Army, with results meeting the original requirements. The same year, the State Council of the People's Republic of China (SCoPRC) and CMC formally designated Fenglei-7 a weapon to enter Chinese service by 1985, and the office of the National Defense of SCoPRC and People's Liberation Army General Staff Department designated Shenyang J-8 as the standard carrier of Fenglei-7. Additionally, in 1980, the 3rd Machinery Ministry of the Chinese Defense Ministry also recommended (and obtained permission) to add Xian JH-7 as the standard aerial platform carrying Fenglei-7. By the end of 1980, the pre-production series Fenglei-7 totaling nineteen has been built, designated as Batch "00". At the beginning of 1981, due to military budget cuts, the 8th Bureau of the Machinery Ministry of the Defense Ministry decided to cancel the Fenglei-7 production program, but many of the subsystems were allowed to continue as research and developmental (R & D) projects. The continuation of the most subsystem was partially due to the fact that the performance of Batch "00" is nearly identical to AGM-45 it was based on, which was not adequate enough to meet the former-Soviet threat China faced, so further development was needed for improvement by incorporating experienced gained from Chinese attempt to reverse engineer AGM-78.
1980年3月，两枚装有FG101火箭发动机的原型在人民解放军第31基地成功完成了测试飞行，结果达到了初始要求。同年，中华人民共和国国务院和中央军委正式指定风雷七号为1985年进入中国服役的武器，国防部办公室和中国人民解放军总参谋部指定为沈阳J-8是风雷7号的标准空中平台。此外，在1980年，中国国防部第三机械部还建议（并获得许可）增加西安JH-7，作为搭载“风雷7”的标准空中平台。到1980年底，已生产出总共19枚的预生产系列“风雷7号”，命名为“ 00”批次。 1981年初，由于削减军事预算，国防部机械部第8局决定取消风雷7的生产计划，但许多子系统被允许研发（R&D）项目继续进行。大多数子系统的后续部分由于“ 00”批次的性能几乎与其所基于的AGM-45相同，它不足以应付中国面临的前苏联威胁，因此需要进一步发展，需要结合中国尝试AGM-78逆向工程获得的经验来进行改进。
From 1978 onward, the 254th Factory completed two set of 10-cm high frequency (HF) radio fuse based on that of AGM-45, and later another 3 sets incorporating improvement from AGM-78. After indoor tests, field tests were conducted with the help of Unit 81032 and Unit 86001 of the People's Liberation Army in October 1982, with good results. On May 16, 1983, the R & D bureau of the Chinese Aerospace Ministry held an onsite evaluation at the 254th Factory, concluded that the design was successful. Development of rudder control mechanism of the missile begun in 1977, and the first batch of three were proved to either reaching or exceeding the requirement. Field tests of the rudder control mechanism of the missile begun in December 1981 and was completed by the end of 1982. On July 14, 1983, the Chinese Aerospace Ministry certified the development being successful and ready for mass production if needed. From 1978 onward, 254th Factory completed four seekers in two batches (with two in each batch), the first batch was based on that of AGM-45, and the second batch incorporating some technologies of AGM-78. On May 12, 1983, the Chinese Aerospace Ministry certified the design. In 1984, these three R & D projects were awarded the 3rd place in the Awards for the Great Science and Technologies given by the COSTIND. The importance of these projects, however, is that they would be later used on HQ-61 ARM developed later.
After the initial preproduction series Batch "00", Fenglei-7 was terminated. All of the nineteen missiles produced when to the Test Flight Regiment of the People's Liberation Army Air Force for evaluation purposes, and it is believed that all Fenglei-7 missiles produced have been exhausted during these tests. According the evaluation, the performance of Fenglei-7 is nearly identical to that of AGM-45, only slightly better, but not much. Based on Fenglei-7 and the subsequent R & D projects branched out from it, China would later develop a successor based on HQ-61 SAM, incorporating all the expertise gained.
Type air-to-air missile
Place of origin China
In service 1964 to 1985
Used by China
Manufacturer Luoyang Electro-Optics Technology Development Center
Produced 1966 to 1985
Weight 150 kg (PL-4A), 148 kg (PL-4B)
Length 3.235 m (PL-4A), 3.128 m (PL-4B)
Diameter 190 mm
Warhead 30 kg high explosive
mechanism Impact / proximity
Propellant solid fuel
range 18 km (PL-4A), 8 km (PL-4B)
Flight ceiling 21 km maximum
Flight altitude 30 meter minimum
Speed ≈ Mach 2.2 – 2.25
system Semi-active radar homing (PL-4A) and Infrared homing (PL-4B)