AIM-9 Sidewinder

The AIM-9 was a product of the US Naval Weapons Center at China Lake in the Mojave Desert. It features a lightweight, compact design with cruciform canards and tail fins. It uses a solid rocket motor for propulsion, similar to most conventional missiles, a continuous-rod fragmentation warhead, and an infrared seeker. The seeker tracks a difference in temperatures detected and uses proportional guidance to achieve impact. Older variants such as the AIM-9B with uncooled seeker heads could track only the high temperatures of engine exhaust, making them strictly rear-aspect. Later variants, however, featured liquid nitrogen coolant bottles in the launchers, allowing the missile to track any part of the aircraft heated by air resistance due to high-speed flight, giving modern Sidewinders all-aspect capabilities. The nose canards provide maneuverability for the AIM-9, with the AIM-9X using thrust vectoring to augment this. The hot gases generated were used to actuate the nose canards in older models, while newer variants use thermal batteries. To minimize the amount of energy devoted to actuating control surfaces, the AIM-9 does not use active roll stabilization. Instead, it uses rollerons, small finned metal discs protruding out of the aft end of the tips of the tail fins which are spun by the passing airflow as the missile flies through the air, providing gyroscopic stabilization. The AIM-9 uses a passive infrared proximity fuze to detonate its warhead near an enemy aircraft, scattering fragments that aim to damage the aircraft, rendering it inoperable. The continuous rod warhead features rods welded together to form a cylindrical outer shell, with explosive filler inside. Upon detonation, the rods expand in a toroidal shape, ensuring that at least some portion of the shrapnel hits enemy aircraft. Newer models of the AIM-9 sought to increase the range that the seeker head's gimbal can turn, allowing the missile to track aircraft at greater angles from its direct line of sight, or boresight. Models such as the AIM-9L, AIM-9M, and AIM-9X feature high off-boresight capabilities, meaning they are able to track targets at high seeker gimbal angles, or highly distant from the boresight. == Guidance ==

The Sidewinder is guided not by the actual position recorded by the detector, but by the change in position since the last sighting. So if the target remains at 5 degrees left between two rotations of the mirror, the electronics would not output any signal to the control system. Consider a missile fired at right angles to its target; if the missile is flying at the same speed as the target, it should "lead" it by 45 degrees, flying to an impact point far in front of where the target was when it was fired. If the missile is traveling four times the speed of the target, it should follow an angle about 11 degrees in front. In either case, the missile should keep that angle all the way to interception, which means that the angle that the target makes against the detector is constant. It was this constant angle that the Sidewinder attempted to maintain. This "proportional pursuit" system is straightforward to implement and offers high-performance lead calculation almost for free and can respond to changes in the target's flight path, which is much more efficient and makes the missile "lead" the target. == History ==

Origins during flight testing at NAWS China Lake, 1952 During World War II, various researchers in Germany designed infrared guidance systems of various complexity. The most mature development of these, codenamed Hamburg, was intended for use by the Blohm & Voss BV 143 glide bomb in an anti-ship role. Hamburg used a single IR photocell as its detector along with a spinning disk with lines painted on it, alternately known as a "reticle" or "chopper". The reticle spun at a fixed speed, causing the output of the photocell to be interrupted in a pattern, and the precise timing of the resulting signal indicated the bearing of the target. Although Hamburg and similar devices like Madrid were essentially complete, the work of mating them to a missile had not been carried out by the time the war ended. In the immediate post-war era, Allied military intelligence teams collected this information, along with many of the engineers working on these projects. Several lengthy reports on the various systems were produced and disseminated among the Western aircraft firms, while a number of the engineers joined these companies to work on various missile projects. By the late 1940s a wide variety of missile projects were underway, from huge systems like the Bell Bomi rocket-powered bomber to small systems like air-to-air missiles. By the early 1950s, both the US Air Force and Royal Air Force had started major IR seeker missile projects. It did not receive official funding until 1951 when the effort was mature enough to show to Admiral William "Deak" Parsons, the Deputy Chief of the Bureau of Ordnance (BuOrd). It subsequently received designation as a program in 1952. Originally called the Sidewinder 1, the first live firing was on 3 September 1952. The missile intercepted a drone for the first time on 11 September 1953. The missile carried out 51 guided flights in 1954, and in 1955 production was authorized. In 1954, the US Air Force carried out trials with the original AIM-9A and the improved AIM-9B at the Holloman Air Development Center. The first operational use of the missile was by Grumman F9F-8 Cougars and FJ-3 Furies of the United States Navy in the middle of 1956. The AIM-9A and AIM-9B were originally fitted with a non-propulsive attachment (NPA) for their MK 15 and MK 17 rocket motors. If the motor accidentally ignited while kept in storage, during transport, or while it was fitted to the aircraft hardpoints, the NPA would direct the exhaust gases at right angles rather than straight back. In these cases, the missile would not move. While the NPA safety device itself suffered no failures, some ordnance men forgot to remove them after hanging the missiles in the hardpoints. When the pilots attempted to fire the missiles in flight, the hot exhaust gases were redirected directly towards the wings, severely damaging the aircraft. After losing three aircraft in this manner, the US Navy withdrew the NPA from use. AIM-9B (AAM-N-7 Sidewinder IA) (USAF/USN) test-firing an AIM-9 Sidewinder against a QF-80 target drone at Eglin Air Force Base The AIM-9B is very similar to the AIM-9A, but the "B" has a more sophisticated rear and more aerodynamical front fins. The AIM-9B is a very limited weapon, but it had no serious competitors and counters when it was introduced, causing it to be adopted by the USAF and NATO as a standard weapon, with around 80,000 units being produced from 1958 to 1962. AIM-9D derivatives ATM-9D (USN): AIM-9D used for captive flight target acquisition training. AIM-9H derivatives ATM-9H: Was a training version of the AIM-9H for captive flight target acquisition. The AIM-9J was an upgrade to the AIM-9E. It included: • The partial replacement of old-fashioned tube electronics with solid-state electronics. • A longer-burning gas generator, which increased flight time to 40 seconds. • More powerful actuators, driving new square-tipped double-delta canards. This doubled the single-plane "g" capability. Around 6,700 AIM-9Js were built from 1972 onward. These were mostly converted existing AIM-9B/E missiles. AIM-9J variants AIM-9J: The base variant. AIM-9J-1 (AIM-9N): AIM-9J-1 (later redesignated the AIM-9N) was an upgrade to the AIM-9J. The AIM-9N had a similar missile configuration to the AIM-9J, but the three main circuit boards were substantially redesigned to help improve seeker performance. Around 7,000 of the AIM-9N were built/rebuilt. AIM-9J-3: AIM-9J-1 with the new SR116 motor. AIM-9P The AIM-9P Sidewinder missile was a USAF sponsored family of export missiles based on the AIM-9J/N, and would be upgraded multiple times over its lifespan. The AIM-9P was an improved AIM-9J with a new motor, fuze and better reliability. It included a greater engagement range, allowing it to be launched farther from the target. The AIM-9P was more maneuverable than the AIM-9J, and also included improved solid-state electronics that increased reliability and maintainability. The AIM-9P was either a rebuilt B/E or J or all-new production. Deliveries of the AIM-9P began in 1978. AIM-9P Variants AIM-9P: The base model. AIM-9P-1: Introduced the DSU-15/B AOTD laser proximity fuze, replacing the previous infrared influence fuze with an active optical target detector. AIM-9P-2: Includes a reduced-smoke rocket motor. AIM-9P-3: Includes a reduced-smoke motor, an active optical target detector, an improved guidance and control section, mechanical strengthening to the warhead, guidance system and control section, and a new insensitive munitions warhead. The warhead uses a new explosive material, this explosive material is less sensitive to high temperature and has a longer shelf life. AIM-9P-4: Introduced the ALASCA features and technology found on the AIM-9L/M variants. AIM-9P-5: Added improved IRCCM from the AIM-9M. AIM-9P derivatives RB24J: Swedish designation for the AIM-9P-3 Note: the speed of the B model was around 1.7 Mach and the other models above 2.5. Later generation all-aspect variants AIM-9L (USAF/USN) warhead and rocket motor, for training purposes. The next major advance in IR Sidewinder development was the AIM-9L ("Lima") model which was in full production in 1977. This was the first "all-aspect" Sidewinder with the ability to attack from all directions, including head-on, which had a dramatic effect on close-in combat tactics. Its first combat use was by a pair of US Navy F-14s in the Gulf of Sidra in 1981 versus two Libyan Sukhoi Su-22s, both of the latter being destroyed by AIM-9Ls. Its first use in a large-scale conflict was by the United Kingdom during the 1982 Falklands War. In this campaign the "Lima" reportedly achieved kills from 80% of launches, a dramatic improvement over the 10–15% levels of earlier versions, scoring 17 kills and 2 shared kills against Argentine aircraft. AIM-9L Derivatives DATM-9L (USAF/USN): This is an AIM-9L used to train ground personnel in missile assembly, disassembly, loading, transportation, and storage procedures and techniques. • AIM-9M-1 (USN): The AIM-9M-1 has very little information other than it uses the same Guidance Control System (GCS) as the AIM-9M-3. • AIM-9M-2: No information other than the confirmation of its existence. • AIM-9M-3 (USN): The only information regarding the AIM-9M-3 is that it uses the same GCS as the AIM-9M-1. • AIM-9M-4 (USN): AIM-9M variant used by United States Navy, using a different GCS, other information on them is currently unknown. • AIM-9M-5: No information other than the confirmation of its existence. • AIM-9M-6 (USN): AIM-9M variant used by United States Navy using a different GCS, other information on them is currently unknown. • AIM-9M-7: Variant modified for Operation Desert Storm/Shield to combat expected threats better. The nature of the upgrade is unknown. AIM-9M Derivatives • AIM-9Q (USN): The AIM-9Q is an AIM-9M modified with upgraded guidance-control section, further information on the missile is unknown and it was either cancelled or became an AIM-9M sub-variant. The surfaces may be permanently "clipped", or may fold out when the missile is launched. AIM-9X (USAF/USN) F/A-18C Hornet in 2004 Hughes Electronics was awarded a contract for development of the AIM-9X Sidewinder in 1996 after a competition against Raytheon for the next short-range aerial combat missile, though Raytheon purchased the defense portions of Hughes Electronics the following year. The AIM-9X entered service in November 2003 with the USAF (the lead platform was the F-15C) and the USN (the lead platform was the F/A-18C) and is a substantial upgrade to the Sidewinder family featuring an imaging infrared 128×128 element focal-plane array (FPA) seeker with claimed 90° off-boresight capability, compatibility with helmet-mounted displays such as the new U.S. Joint Helmet Mounted Cueing System (JHMCS), and a totally new two-axis thrust-vectoring control (TVC) system providing increased turn capability over traditional control surfaces (60 g). Using the JHMCS, a pilot can point the AIM-9X missile's seeker and "lock on" by simply looking at a target, thereby increasing air combat effectiveness. It retains the same rocket motor, fuze and warhead of the AIM-9M, but its lower drag gives it improved range and speed. The AIM-9X also includes an internal cooling system, eliminating the need to use launch-rail nitrogen bottles (U.S. Navy and Marines) or internal argon bottles (USAF). It also features an electronic safe and arm device similar to the AMRAAM, allowing for a reduction in minimum range, and reprogrammable infrared Counter Counter Measures (IRCCM) capability that coupled with the FPA provides improved look down into clutter and performance against the latest IRCM. Though not part of the original requirement, the AIM-9X demonstrated potential for lock-on after launch capability, allowing for possible internal use for the F-35 Lightning II, F-22 Raptor and even in a submarine-launched configuration for use against ASW platforms. The AIM-9X has been tested for a surface attack capability, with mixed results. Block II Testing work on the AIM-9X Block II version began in September 2008. The Block II adds lock-on after launch capability with a datalink, so the missile can be launched first and then directed to its target afterwards by an aircraft with the proper equipment for 360-degree engagements, such as the F-35 or the F-22. By January 2013, the AIM-9X Block II was about halfway through its operational testing and performing better than expected. NAVAIR reported that the missile was exceeding performance requirements in all areas, including lock-on after launch (LOAL). One area where the Block II needs improvement is helmetless high off-boresight (HHOBS) performance. It is functioning well on the missile, but performance is below that of the Block I AIM-9X. The HHOBS deficiency does not impact any other Block II capabilities, and is planned to be improved upon by a software clean-up build. Objectives of the operational test were due to be completed by the third quarter of 2013. However, as of May 2014 there have been plans to resume operational testing and evaluation (including surface-to-air missile system compatibility). , Raytheon had delivered 5,000 AIM-9X missiles to the armed services. On 18 June 2017, after an AIM-9X did not successfully track a targeted Syrian Air Force Su-22 Fitter, US Navy Lt. Cmdr. Michael "Mob" Tremel flying a F/A-18E Super Hornet used an AMRAAM AAM to successfully destroy the enemy aircraft. There is a theory that the Sidewinder is tested against American and not Soviet/Russian flares. The Sidewinder is used to rejecting American but not Soviet/Russian flares. Similar issues arose from the testing of the AIM-9P model. The missile would ignore American flares but go for Soviet ones due to their "different burn time, intensity and separation." Block III In September 2012, Raytheon was ordered to continue developing the Sidewinder into a Block III variant, even though the Block II had not yet entered service. The USN projected that the new missile would have a 60 percent longer range, modern components to replace old ones, and an insensitive munitions warhead, which is more stable and less likely to detonate by accident, making it safer for ground crews. The need for the AIM-9 to have an increased range was caused by digital radio frequency memory (DRFM) jammers that can blind the onboard radar of an AIM-120D AMRAAM, so the Sidewinder Block III's passive imaging infrared homing guidance system was seen as a useful alternative. Although it could supplement the AMRAAM for beyond visual range (BVR) engagements, it would still be capable of performing within visual range (WVR). Modifying the AIM-9X was seen as a cost-effective alternative to developing a new missile in a time of declining budgets. To achieve the range increase, the rocket motor would have a combination of increased performance and missile power management. The Block III would "leverage" the Block II's guidance unit and electronics, including the AMRAAM-derived datalink. The Block III was scheduled to achieve initial operational capability (IOC) in 2022, following the increased number of F-35 Lightning II Joint Strike Fighters to enter service. The Navy pressed for this upgrade in response to a projected threat which analysts have speculated will be due to the difficulty of targeting upcoming Chinese fifth-generation jet fighters (Chengdu J-20, Shenyang J-31) with the radar-guided AMRAAM, specifically that Chinese advances in electronics will mean Chinese fighters will use their AESA radars as jammers to degrade the AIM-120's kill probability. However, the Navy's FY 2016 budget canceled the AIM-9X Block III as they cut down buys of the F-35C, as it was primarily intended to permit the fighter to carry six BVR missiles; the insensitive munition warhead will be retained for the AIM-9X program. == Combat ==

Combat debut: Taiwan Strait, 1958 The first combat use of the Sidewinder came on 24 September 1958 by the Republic of China (Taiwan) Air Force during the Second Taiwan Strait Crisis. At the time, ROCAF North American F-86 Sabres were routinely engaged in air battles with the People's Republic of China over the Taiwan Strait. In similar fashion to Korean War encounters between the F-86 and earlier MiG-15, high-flying PRC MiG-17s cruised above the ROC Sabres, immune to their .50-cal guns and only fighting when conditions favoured them. In a highly secret effort, the United States provided a few dozen Sidewinders to ROC forces and an Aviation Ordnance Team from the U.S. Marine Corps to modify their aircraft to carry the Sidewinder. In the first encounter on 24 September 1958, ROCAF pilots used the Sidewinders to ambush the MiG-17s as they flew past. This action marked the first successful use of air-to-air missiles in combat, the downed MiGs being the first casualties. They reverse-engineered a copy of the Sidewinder, which was manufactured as the Vympel K-13/R-3S missile, NATO reporting name AA-2 Atoll. The Vympel K-13 entered service with Soviet air forces in 1960. Vietnam War service 1965–1973 Performance of the 454 Sidewinders launched during the war was not as satisfactory as hoped. Both the USN and USAF studied the performance of their aircrews, aircraft, weapons, training, and supporting infrastructure. The USAF conducted the classified Red Baron Report while the Navy conducted a study concentrating primarily on performance of air-to-air weapons that was informally known as the "Ault Report". Both services subsequently modified their AIM-9s to improve performance and reliability. Vietnam War AIM-9 claimed aerial combat kills In total 452 Sidewinders were fired during the Vietnam War, resulting in a kill probability of 18%. The Services and the Department of Defense were shocked by the poor missile performance - pre-war operational tests predicted that the AIM-9 was expected to hit 65% of the time. The missile testing program, however, did not reflect how the missiles would be used. Almost all the tests were against non-maneuvering drone targets at high altitudes, many of them with artificially strengthened radar returns. 1982 Falklands War The United States Air Force sold the United Kingdom 200 AIM‑9L Sidewinder missiles for use on Harrier aircraft during the Falklands War. The Royal Navy's Sea Harriers made extensive use of the missile's all‑aspect capability. Contemporary sources agree that 24 AIM‑9Ls were launched by Sea Harriers operating from and , with 21 striking their targets, giving an overall hit rate of 88 per cent. Of the three unsuccessful firings, one was launched beyond its seeker's effective range, one suffered a malfunction, and one failed after the target escaped into cloud cover. The missile's infrared seeker proved especially effective against the hot exhaust of Argentine jets against the cold South Atlantic skies. Six days later, another object was shot down near Alaska. On 11 and 12 February two more objects were shot down, over Yukon, Canada and Lake Huron in Michigan respectively. 2023 Israel–Gaza war On 2 November 2023, Israeli Air Force claimed one of its F-35I have shot down an unidentified cruise missile, using an AIM-9X Sidewinder. Russian invasion of Ukraine On 3 May 2025, the head of the Ukrainian Main Directorate of Intelligence (HUR), lieutenant general Kyrylo Budanov claimed that three MAGURA V7 naval drones armed with AIM-9 Sidewinders modified for surface-to-air operation shot down two Russian Su-30 fighter jets in the Black Sea. The Russian Defense Ministry did not comment, but Russian sources report that the pilots of one fighter were rescued by a cargo ship, whose crew received an award. On September 18, 2025, during a massive missile-drone attack, a video surfaced on social networks showing an F-16 of the Ukrainian Air Force shooting down a Russian Shahed-136 kamikaze drone with an AIM-9L missile. == Sidewinder descendants ==

Anti-tank variants against an M41 Walker Bulldog at China Lake, 1971 Naval Air Weapons Station China Lake experimented with Sidewinders in the air-to-ground mode including use as an anti-tank weapon. Starting from 2008, the AIM-9X demonstrated its ability as a successful light air-to-ground missile. In 2016, Diehl closed a deal with the Federal Office of Bundeswehr Equipment, Information Technology and In-Service Support to develop a laser guided Air-To-Ground variant of the Sidewinder missile based on the AIM-9L variant. In testing with the Swedish Defence Materiel Administration a Saab JAS 39 Gripen could hit one stationary and two moving targets. On 28 February 2018, the Iranian Islamic Revolutionary Guard Corps unveiled an anti-tank derivative of the Sidewinder missile named "Azarakhsh" intended for use by Bell AH-1J SeaCobra attack helicopters. ==Later developments==

High Altitude Project (HAP) Under the High Altitude Project, engineers at China Lake mated a Sidewinder warhead and seeker to a Sparrow rocket motor to experiment with usefulness of a larger motor, giving it a longer range. This was intended to provide the F-4 Phantom II the capability to intercept the Mikoyan MiG-25; eight prototype missiles were built. Other ground launch platforms MIM-72 Chaparral The MIM-72 Chaparral is an American-made self-propelled surface-to-air missile (SAM) based on the AIM-9 Sidewinder air-to-air missile system. MIM-72 Variants • MIM-72A (USAF): missile was based on the AIM-9D Sidewinder. The main difference is that to reduce drag only two of the fins on the MIM-72A have rollerons, the other two having been replaced by fixed thin fins. The MIM-72's MK 50 solid-fuel rocket motor was essentially identical to the MK 36 MOD 5 used in the AIM-9D Sidewinder. • MIM-72B (USAF): It was a training missile with the radar fuze replaced with an IR model for use against target drones. • MIM-72C Improved Chaparral (USAF): The MIM-72C used the advanced AN/DAW-1B seeker with all-aspect capability, as well as a new doppler radar fuze and M250 blast-frag warhead. The fuze and warhead were adapted from the earlier Mauler program. C models were deployed between 1976 and 1981, reaching operational status in 1978. • MIM-72D: The MIM-72D was built for export, combining the seeker of the "A" with the improved M250 warhead. • MIM-72E (USAF): MIM-72C missiles retrofitted with a new M121 smokeless motor, which greatly reduced the smoke generated on firing allowing for easier follow-up shots and making it harder for enemy aircraft to find the launch site. • MIM-72F: It was an export model, being virtually identical to the MIM-72E, just being newly built . • MIM-72G (USAF): This was the final upgrade to the MIM-72, fitting the missile with the new AN/DAW-2 rosette scan seeker based on the seeker in the FIM-92 Stinger POST, offering a larger field of view and improved resistance to countermeasures. This was retrofitted to all Chaparral missiles during the late 1980s, and was produced between 1990 and 1991. • MIM-72H Is an export version of the MIM-72F • MIM-72J is an MIM-72G with a downgraded guidance and control section, and was also intended for export. • MIM-72 Derivatives: • RIM-72C Sea Chaparral (USN): A naval version of the MIM-72 was also developed, based on the C version of the missile, it was evaluated but not deployed by the US Navy. However it was exported and adopted by Taiwan. • M30: Inert training missile based on MIM-72A, replicating a live "A" using the original Mk28 seeker head. • M33: Inert training version of MIM-72C, replicating the "C" and later and was fitted with the AN/DAW series of seekers. AIM-9X MML In 2016, the AIM-9X was test fired from a Multi-Mission Launcher at the White Sands Missile Range in New Mexico, USA. During testing with the MML, the AIM-9X experienced issues with overheating. These issues have since been resolved. In September 2021, the U.S. Army signed a contract with Dynetics to build prototypes for its Indirect Fires Protection Capability (IFPC), using an MML-based launcher firing the Sidewinder to counter UAVs and cruise missiles. It is planned to be put into service in 2023. AIM-9X NASAMS In May 2019, the AIM-9X Block II was test fired from the National Advanced Surface to Air Missile System (NASAMS) at the Andøya Space Center in Norway. FrankenSAM In late 2022, the United States and Ukraine began working on a program to adapt older AIM-9M Sidewinders into surface to air missiles, as part of a wider program known as "FrankenSAM", in an attempt to better protect Ukraine against Russian airstrikes of critical power infrastructure during the Russo-Ukrainian War. On 24 October 2023, a Ukrainian official said: "Those [AIM-9] missiles were out of operation...We found a way of launching them [Sidewinders] from the ground. It's a kind of self-made air defence." Naval drone platforms According to Budanov, the HUR began development on a MAGURA V5 unmanned surface vehicle armed with AIM-9 Sidewinders in January 2025. He also told the War Zone that "We use a couple of models [of missiles] on our Magura-7, but the best results [come from] the AIM-9." == Operators ==

Current operators • : AIM-9L/M • • • • : AIM-9M/9X block II/block II+ • • • • • • : AIM-9L/I • • • • • • • F-104G Starfighter in 1979. • • : AIM-9B/L • • : AIM-9B/J/P/L/M/9X Block II • • • • : 127 AIM-9X-BII Sidewinder in inventory and 401 AIM-9X-BII Sidewinder on order. Unknown number of AIM-9Ms donated by the United States in August 2023. • • Former operators • • : AIM-9B, AIM-9H • • • • • • • • • Future operators • : Slovak Air Force bought 100 AIM-9 Sidewinder missiles for their F-16 Block 70/72. • : Bulgarian Air Force F-16 Block 70 Aircraft are going to be armed with AIM-9X Block II missiles. • : AIM-9X Please note that this list is not definitive. == See also ==