Hughes AIM-4/AIM-26 Falcon

     Notes:  The Falcon was the first operational air-to-air missile.  Though not particularly reliable or accurate in its early iterations, it did provide a valuable technological base for later developments.  Development began in late 1946 as a short-range subsonic missile to give bombers a self-defense capability, but quickly changed to a supersonic fighter-launched missile with the designation XAAM-A-2.  In 1950, the Falcon became operational, and in 1951, the designation was changed to F-98, and then changed again to GAR-1 in 1955. AIM-4Ds were initially used by F-4D Phantoms in Vietnam, but quickly withdrawn because the visual ROEs imposed in Vietnam made the long minimum range of the Falcon problematic.  The missile accelerates quickly, but is none too maneuverable; this limits its effectiveness somewhat.  By the early 1970s, the Falcon had largely been replaced by missiles with later technology. The Swedes used a version of the AIM-26B (as the RB-27) for almost two decades after the Falcon had been withdrawn from service elsewhere.

     The original GAR-1 (later AIM-4) used radar-homing guidance with a relatively short range.  The GAR-1 also has no proximity fuze, meaning that the GAR-1 actually had to strike its target before the 3.4-kilogram warhead would detonate.  As the GAR-1 was to be used against large, subsonic bombers, this was not considered a problem at the time.  The GAR-1D (later AIM-4A) offered greater maneuverability due to enlarged control surfaces, including separate auxiliary control surfaces at the rear of the primary fins.  An improved motor also made it a bit faster than the GAR-1. The GAR-2 (AIM-4B) used the same airframe, but was a heat-seeking missile.  The GAR-2A (AIM-4C) had an improved IR seeker.  The GAR-2B (AIM-4D) further improved the IR seeker.

     The GAR-3 (AIM-4E) was a bit larger, with an improved motor and larger warhead, and with the GAR-3, the name of the missile was changed to Super Falcon.  The GAR-3A (AIM-4F) improved the rocket motor further by providing a boost and sustainer motor, as well as improving (slightly) ECM resistance; earlier radar-homing versions were upgraded to this standard. The GAR-4 (AIM-4G) was the heat-seeking variant of the GAR-3A, and also had an improved IR seeker.

     The GAR-11 (AIM-26A; officially the Falcon, but often called the Nuclear Falcon) was a very different type of air-to-air missile.  It was designed to destroy formations of bombers at once, using a small nuclear warhead.  The GAR-11 was developed in 1959, when the radar seeker used in the Falcon was still deemed too inaccurate to ensure bomber destruction; hence the nuclear warhead.  The GAR-11 used a radar proximity fuze, but the range was rather short since the GAR-11’s warhead was much heavier than the standard Falcon.  This meant that the Nuclear Falcon could conceivably put the firing aircraft within range of the EMP, radiation, or even damage or destruction radius of the warhead; the pilot had a shield he could erect over the front of his canopy to prevent flash blinding, but this did not do anything to protect him from anything else.

     The GAR-11A (AIM-26B) Super Falcon was developed as a conventional counterpart to the GAR-11, at the same time as the GAR-11.  It was much larger and heavier than any of the AIM-4 series, and was radar-homing and triggered by a proximity fuze.  The GAR-11A, however, lacked look-down-shoot-down capability, and was primarily used by the Swedes in an improved version.

     Twilight 2000 Notes: Increasing numbers of Falcons and Super Falcons were pulled out of storage, particularly in Europe; they were also adapted to a much wider variety of aircraft than they were originally meant for.

Raytheon AIM-7 Sparrow

     Notes:  Research on what eventually became the AIM-7 began in 1947, when the US Navy asked Sperry to develop a beam-riding version for the standard (at the time) 5-inch HVAR rocket.  The 5-inch diameter of the rocket proved to be too small, so it was enlarged to 8 inches.  The development proved to be full of problems, so much that the first aerial intercept against a drone did not occur until 1952, and the AAM-N-2 Sparrow I (later called the AIM-7A) did not see fleet service until 1956.

     The AIM-7A proved to be a failure.  Beam-riding guidance is inaccurate for an aircraft-launched missile, and the AIM-7A was easily confused by ground clutter.  In addition, the AIM-7A launch system required that the aircraft’s radar be slaved to an optical sight, turning a missile which had decent range (at the time) into a VFR weapon.  The AIM-7A was withdrawn after only 3 years, with only 2000 being built.

     The AAM-N-3 Sparrow II (later called the AIM-7B) was an early attempt at an active-homing missile, developed by Douglas Aviation.  Unfortunately this idea was essentially decades ahead of its time in 1955, and the result was a failure.  The US Navy, who originally asked for the Sparrow II to arm it’s F5D-1 Skylancer, canceled its participation in the Sparrow II program in 1956.  The Canadians then thought the AIM-7B was the perfect armament for the CF-105 Arrow interceptor, and when the CF-105 project died The Sparrow II died its final death.  The AIM-7B is not included in the charts below.  A version of this missile, the AIM-7B Sparrow IIX, was also designed; this was to be armed with the same nuclear warhead as on the MD-2 Genie version of the AIM-4 Falcon, but it too was cancelled along with the CF-105 project.

     The Sparrow III series began in 1955 with the AAM-N-6 (later called the AIM-7C).  It was also at this point that Raytheon became the prime contractor for the AIM-7.  Per4haps the key change in guidance was that the Sparrow III series homed in on a radar lock-on from the firing aircraft.  This can make a missile highly vulnerable to even simple countermeasures, and this was especially true of early-model Sparrow IIIs (countermeasures are one level more effective against the AIM-7C, 7D, and 7E series). 

     The AIM-7C used a 29.5 kg continuous-rod fragmentation warhead and a solid-rocket motor.  Again, only about 2000 were built, due to the imminent introduction of the AAM-N-6a (AIM-7D).  The missile body was essentially the same, but internally, the AIM-7D was quite different.  The AIM-7D used liquid propellant that was inert until ignition, which increased the range and ceiling.  The seeker was improved to allow for higher closing rates of speed (as occurred with head-on shots), and the first ECCM/anti-jamming capability was introduced.  The USAF also used the AIM-7D, calling it the AIM-101 at the time and making it the primary armament of the F-4C Phantom II.  After the AIM-7E was introduced, many surviving AIM-7Ds were converted to training missiles with inert warheads, and designated ATM-7D.

     In 1963, due to the Pentagon’s switch to a common nomenclature system, the earlier versions of the Sparrow were redesignated AIM-7.  The next version of the Sparrow III series was the AIM-7E.  Propellant was changed back to solid fuel, and the engine again increased range.  The AIM-7E was also a bit more agile than its predecessors.  The AIM-7E was employed extensively in Vietnam, where opinions of its effectiveness depended on the pilot – most pilots reviled the AIM-7E due to numerous failures of the engine to fire, the seeker losing track of the aircraft’s lock-on, the fuzes not working, poor maneuverability, and confusion by ground clutter.  On the other hand, some pilots, like the ace Steve Ritchie, swore by the AIM-7E, using it for all five of his MiG kills.  Most pilots in Vietnam learned quickly to fire the AIM-7E (and AIM-7s in general) in pairs to decrease the chance of failures.  These shortcomings led to the introduction of the AIM-7E2 in 1969, with much improved maneuverability, a shorter minimum range, and improved fuzing reliability.  The AIM-7E3 further improved the reliability of the fuzing and also improved the motor start system, and the AIM-7E4 was designed for use with aircraft with higher-power radars (such as the F-14, introduced in 1973).  Otherwise, for game purposes, the AIM-7E3 and E4 are identical to the AIM-7E2.  The AIM-7J is an AIM-7E2 license-built in Japan.  The RIM-7E is an AIM-7E adapted for use as a ship-launched SAM; the RIM-7H is the AIM-7E2 adapted for the same role.  The primary modification for these missiles are snap-open fins, allowing them to be loaded into box launchers.  The various versions of the AIM-7E were the most produced, with almost 30,000 being built.

     1972 brought the AIM-7F.  The AIM-7F had a greatly-increased range due to a dual-thrust motor that provided a quick boost followed by a sustainer.  The guidance and control sections were completely solid-state.  This guidance package was also smaller, allowing the use of a 39 kg warhead.  With the advent of the AIM-7F, the name of the missile was changed from “Sparrow III” to simply “Sparrow.”  The AIM-7G was a version of the AIM-7F designed specifically for use with the F-111D, but did not proceed beyond the prototype stage.  A RIM-7F version was also built.  With the AIM-7F, General Dynamics also began building the Sparrow.

     The designations AIM-7H, AIM-7I, AIM-7K and AIM-7L were either skipped or were unsuccessful research models. The AIM-7M designation was chosen for the next iteration of the Sparrow, due to its use of the new monopulse seeker head that allows better performance at low altitude and in high-ECM environments, as well as bringing true look-down-shoot-down capability.  The AIM-7M includes a digital computer with re-programmable EEPROM modules.  The AIM-7M can operate in a semi-independent manner; once the missile is launched, it uses an autopilot to fly in one of several pre-programmed trajectories, and a lock-on is required only for launch, mid-course update, and terminal guidance.  The warhead has also been replaced by blast-fragmentation warhead, rather than pure fragmentation.  A RIM-7M version was also produced.  The AIM-7N was a prototype improved AIM-7M, but subsequent improvements overtook the program and it was never put into full production.

     The AIM-7P appeared in 1987, with an improved guidance module, a computer that uplinks to the pilot for more accurate mid-course and terminal guidance, and an improved look-down/shoot-down capability.  ECCM has improved so significantly that countermeasure success is degraded by one level.  A RIM-7P version was also built.  The AIM-9P is still in production, primarily for the US Navy in its RIM-7P version and for foreign countries that are unable to afford the AIM-120.  In addition, Raytheon also upgrades earlier versions of the AIM-7 to the AIM-7P standard for those foreign customers as well as the US military.

     The AIM-7Q was essentially a testbed for a new guidance system which used an active-homing head combined with an IR seeker for backup.  If the AIM-7Q lost radar contact with the target due to ECM or standard methods of breaking lock-ons, the IR seeker would take over and guide the missile to the target.  Conversely, the AIM-7Q could be launched as a heat-seeking missile, using brief pulses of radar to confirm the target.  AIM-7Q development apparently ended with no production missiles being fielded.

     The final version of the Sparrow was the AIM-7R.  The AIM-7R used an AIM-7P-type radar guidance module, but it was paired with an IR seeker used to improve terminal guidance, similar to the AIM-7Q.  The onboard computing power was also considerably increased.  Range was increased by enlarging the tail surfaces and making them the only control surfaces, allowing for more fuel to be carried.  In game terms, countermeasure success is degraded by one level, and if the missile loses lock-on and is within 3 km of its target, a roll is immediately made to regain contact.  Though the AIM-7R was set for production, that production was never carried out, due to high development costs and the impending adoption of the AIM-120 AMRAAM missile.  The AIM-7R was cancelled in 1996, but as I often do, I included it anyway just for the heck of it.

     Twilight 2000 Notes: Sparrows were called into increasing use in the Twilight War as supplies of AMRAAM missiles began to be used up.  Most Sparrows used by the United States and NATO in the Twilight War were AIM-7Ps and AIM-7Ms, though some countries were using Sparrows as old as the AIM-7E.

Raytheon AIM-9 Sidewinder

     Notes:  This was the first AAM to be placed into service, and is perhaps the most plentiful AAM in existence.  The designers of the Sidewinder, a small team operating on a shoestring budget when development began at China Lake in 1950, created the first Sidewinder out of almost nothing; the project was drastically underfunded and the designers put a considerable amount of their personal funds into it.  They then developed a working homing head and got the design to be taken seriously by the Navy.  And the rest is history.

     The AAM-N-7 Sidewinder I (later designated the AIM-9A Sidewinder) began low rate initial production for the US Navy in 1955.  Only 240 were built, as they were considered field test weapons.  The AIM-9A had a small 4.5-kilogram blast-fragmentation warhead with an IR seeker which was not cooled like later models would be.  The small warhead was a bit of a problem, since the small size meant it had a kill radius of only 9 meters.  The primitive seeker also meant that the AIM-9A could detect targets within a mere 4-degree field of view, and the firing aircraft must be in the “slot” position – directly behind the target.  To make matters worse, the AIM-9A, though it could turn at 12G, was limited primarily to non-maneuvering targets due to the extremely narrow field of view, and fuzing could be unreliable.  The AIM-9B’s seeker had a greatly-improved field of view, but was otherwise the same as the AIM-9A.  The AIM-9B became the first air-to-air missile to score a kill in September of 1958, when Taiwanese F-86Fs fired them at a gaggle of Chinese MiG-15s – to a great success.  Production of the AIM-9B stopped in 1962, with 80,000 being built. The AIM-9F was the European version of the AIM-9B.  The primary difference is a more sensitive CO2-based cooler for the seeker head.  Also called the AIM-9B FGW.2, the AIM-9F was built in Germany by BGT.

     The AIM-9C was a response to the problems with the AIM-9B, with the US Navy trying another tack with the sidewinder – semi-active radar-homing guidance.  The AIM-9C was also thought to be a way for aircraft that could not use the AIM-7 Sparrow, such as the F-8 Crusader, to be able to use radar-homing missiles (and in fact, the Crusader was the only aircraft to actually carry the AIM-9C in service).  The AIM-9C, however, was perhaps less reliable than the AIM-9B, and only 1000 were built.  Most surviving AIM-9Cs were later rebuilt into AGM-122A Sidearm anti-radar missiles.

     The AIM-9D was developed in tandem with the AIM-9C, but used a new IR seeker.  This seeker had an even narrower field of vision to reduce interference from environmental background radiation like the Sun, clouds, the ground, etc., and it’s more aerodynamic shape allowed for faster speed.  The AIM-9D also features a much larger 11.34-kilogram continuous rod warhead providing the fragmentation effect warhead.  It was built from 1965-69. The AIM-9G was developed for the US Navy, built from 1970-72.  An improved AIM-9D, the AIM-9G improved target acquisition probability by not only allowing the seeker head to use preprogrammed search patterns, but by allowing the seeker head to be slaved to the aircraft’s radar for target acquisition purposes.  (This is called the SEAM upgrade, for Sidewinder Expanded Acquisition Mode.)

     The AIM-9E was the first version of the Sidewinder designed specifically for the US Air Force, though the USAF had already been using earlier versions of the Sidewinder.  The AIM-9E was an AIM-9B with an improved seeker with a higher tracking rate and Peltier cooling for the seeker.  The AIM-9E2 was a version of the basic AIM-9E with a reduced-smoke motor.  The nose of the AIM-9E is longer, and has a conical tip.

     The AIM-9H started out as merely an improved AIM-9F for the US Navy, but quickly the improvements added up.  The AIM-9H featured solid-state electronics that were more stable and allowed for increased accuracy.  The seeker’s tracking rate was greatly increased, as the AIM-9H was more agile than any of its predecessors due to its electronic “brain” and the electronic actuators for the fins.  Some 7700 were built between 1972 and 1974; though they arrived late in the Vietnam War, the AIM-9H’s kill rate was a great improvement over earlier models.  The US Navy planned an upgrade for the AIM-9H that would be designated the AIM-9K, but the Navy and Air Force decided to get on the same sheet of music and develop the AIM-9L instead.

     The AIM-9J was an improved AIM-9E.  The AIM-9J used partial solid-state electronics, an improved motor with a longer burn time, more powerful fin actuators that increased agility, and larger, double-delta canards that further increased agility.  It did not, however, quite match the capabilities of the AIM-9H, though it was much less expensive.  Most AIM-9Js were made by upgrading AIM-9Bs and AIM-9Es, but new production versions were also built, and designated AIM-9J3.  The AIM-9N was at first designated the AIM-9J1, and is an incremental upgrade of the AIM-9J with an improved seeker module (decoying the AIM-9N with flares, natural phenomena, or IRCM is done at a -2 penalty).  The rocket motor was also improved for a longer burn time, and the warhead was also somewhat improved.  AIM-9Ns were all new production missiles, and many were exported instead of being used by US forces.

     The AIM-9L, the first joint-service Sidewinder, was a huge improvement over its predecessors, and based on the AIM-9H.  Service began in 1974.  It was the first heat-seeking missile that could attack its target from any direction – in addition to homing in on engine exhaust, it could home on the heat of the engines themselves and heat caused by friction on the leading edges of an aircraft.  The AIM-9L essentially looked at the heat generated by the entire target rather than by just the tailpipes.  The AIM-9L used large-span double-delta canards, solid state electronics, and electrical control actuators, all of which increased accuracy and agility.  The seeker used argon-cooled Indium Antimonide, and the fuze was a proximity fuze enhanced by a short-range laser (the AOTD fuze, or Active Optical Target Detector), a much more reliable fuze than on earlier Sidewinders.  Warhead weight was about double that of the AIM-9J, but it used more modern explosives and a blast-fragmentation warhead with an annular fragmentation pattern.  The AIM-9L was first used in combat by Royal Navy Harriers during the Falklands War, and over 16,000 were built by two companies in the US as well as by Germany and Japan.  The AIM-9M is a further development of the AIM-9L, replacing it in production.  The AIM-9M has a reduced-smoke motor, an improved guidance module, resistance to countermeasures (decoying the AIM-9M with flares, natural phenomena, and IRCM units is one level more difficult), and generally improved reliability.  The blast pattern of the warhead is also somewhat improved, though the warhead is almost identical to that of the AIM-9L.  All known Sidewinder kills during Desert Storm were with AIM-9Ms.  The AIM-9M began service in 1982.  The AIM-9S is an export version of the AIM-9M, with the main difference being that the improved countermeasure resistance is removed.

     Originally designed specifically for export, the AIM-9P has found itself in use by the US Air Force in recent years.  The AIM-9P is a simpler, less expensive Sidewinder, without many of the advanced electronics and seeker features of the AIM-9L and AIM-9M.  There are several flavors of the AIM-9P, depending upon the needs of the receiving country and what the US is willing to let them have; they are all based on the AIM-9B/E/J series, and many are in fact rebuilds.  The AIM-9P1 has a laser proximity fuze for increased reliability; the AIM-9P2 adds a reduced-smoke motor to that.  The AIM-9P3 adds a more advanced warhead, improved guidance electronics, and faster-actuating control surfaces.  The AIM-9P4 replaces the seeker with one based on (but not quite as advanced as) the AIM-9L/M.  The AIM-9P5 adds IRCM resistance similar to that of the AIM-9M.

     The AIM-9X is the newest Sidewinder, combining the best features of earlier Sidewinders, technology of several advanced experimental versions of the Sidewinder, and a host of new ideas.  Development began in 1991, operational deployment began in 2003, and full-rate production began in 2004.  The AIM-9X was at first developed by Hughes, but since Raytheon now owns Hughes, the AIM-9X is a Raytheon product.  The AIM-9X has the rocket motor and the warhead of the AIM-9M, inside a new airframe; the greatly decreased drag gives the AIM-9X increased speed and range.  The fins of the AIM-9X are much smaller than any other Sidewinder; they are there primarily for stability, with steering of the AIM-9X being done by jet vanes (much like thrust vectoring) at the exhaust.  The small fins of the AIM-9X allow it to fit inside the weapon bays of the F/A-22 and F-35, but still fit on any standard weapon rail able to take a Sidewinder.  The AIM-9X can also interface with the new helmet-mounted sights being fielded on some US and NATO aircraft (the JHMCS).  The AIM-9X uses an imaging focal plane array seeker that has a 90-degree off-boresight capability; along with its jet-vane steering, this gives the AIM-9X phenomenal accuracy and agility.  The AIM-9X has lock-after-launch capability; the pilot of an aircraft equipped with the AIM-9X and the JHMCS can launch the missile before he has a tone (has acquired the target), then steer the AIM-9X into a position where the missile can acquire the target.  It also incorporates an advanced version of SEAM. The resistance to countermeasures is so great that the AIM-9X is two difficulty levels less likely to be thrown off by natural phenomena, flares, or IRCM systems.

     In the Vietnam War and the Middle Eastern Wars, some American and Israeli pilots discovered that some ground vehicles (particularly older trucks) gave off a tone strong enough for Sidewinders to home in on them.

     Twilight 2000 Notes: The AIM-9X is not available in the Twilight 2000 timeline.  The AIM-9S is rare.

Raytheon AIM-54 Phoenix

     Notes:  The Phoenix is a sophisticated, costly, and large missile intended for long-range defense of US Navy vessels, and it had a somewhat tortuous history.   Development of what became the Phoenix actually began in late 1960, after the US Navy’s long-range F6D Missileer interceptor and it’s AAM-N-10 Eagle BVR missile was cancelled due to large cost overruns.  Hughes Aerospace, then the developer of the missile, then turned to more off-the-shelf technology – an upgrade of the AIM-47 Falcon missile and it’s associated fire control system, both of which had been previously developed for use by the abortive USAF YF-12A interceptor version of the SR-71 Blackbird.  The upgraded missile and fire control system was to arm the US Navy’s projected F-111B.  Tests of the AIM-54A began in 1965, but by 1967, the F-111B was itself cancelled.  However, by 1968, development of the F-14 Tomcat began, and the fire control system and the Phoenix were incorporated into the Tomcat.  Squadron service of the AIM-54A finally began in 1974, almost 15 years after its conception.

     In form, the AIM-54A resembles a huge version of the AIM-4 Falcon, but it is a far different beast.  The Phoenix has a small radar set in its nose, allowing it to home in on a target with minimal guidance updates from the Tomcat once it has closed to within 72 kilometers.  Once the Phoenix has closed to within 18.2 kilometers of its target, the Phoenix no longer needs targeting updates from the Tomcat and it guides itself.  (If fired from inside of 18.2 kilometers, the Phoenix immediately goes to active homing mode.)  The Phoenix has a limited look-down, shoot-down capability (rough terrain can screw up target acquisition), a huge 60 kilogram blast-fragmentation warhead, and a very long range, due to its intended role of destroying Soviet maritime bombers.  The Phoenix has three fuzing systems – radar proximity, IR proximity, and impact – to further reduce a miss due to bad fuzing.

     The AIM-54B appeared in US Navy inventories in 1977 – but only for a very short time.  What exactly the AIM-54B variant was is uncertain, but it was most likely version to test less expensive manufacturing methods, such as sheet steel for the fins.  The AIM-54B was never in official US Navy use, and it is likely that the cost-cutting measures were incorporated into production AIM-54As and the newer AIM-54C.

     The AIM-54C began development in 1977, with squadron service starting in 1982.  The AIM-64C used primarily digital instead of analog components, and look-down-shoot-down capability was improved to increase reliability over rough land terrain and make it more capable against small cruise missiles and antishipping missiles.  Perhaps the most important improvement was it’s ECCM system – The AIM-54C is one level harder to decoy than the AIM-54A.  The motor was improved, giving the Phoenix increased range and speed.

     Several versions of the AIM-54C were put into service as time went by, each having incremental improvements.  One of these was an upgraded warhead, with a 20% greater effectiveness.  Another set of improvements was aimed at reliability, improving resistance to both the weather at sea and temperature changes as the Tomcat climbs and dives.  These versions are often called the AIM-54C+.  Later, ECCM capabilities were further improved (making them, in game terms, two levels more difficult to decoy), and the computer aboard the Phoenix was given EEPROM memory and better signal processor software, as well as EMP hardening.  This version is referred to as the AIM-54C ECCM/Sealed.

     By 2004, the Phoenix was officially retired from fleet service, due to its cost and the fact that the Soviet maritime bomber threat has all but disappeared.  The Tomcat itself was retired in 2007, and with it, the only US aircraft capable of using the Phoenix.  Rumors say that the Iranians still have a dozen or so operational AIM-54As for its F-14s.

     Twilight 2000 Notes: In the Twilight 2000 timeline, the Phoenix managed to bring down most of the Russian maritime bomber fleet within weeks of the start of hostilities, but stocks dwindled very fast, and could never be replenished as quickly as desired.  By 2000, 99% of the available stocks had been expended, and facilities for its production had been destroyed.

     Merc 2000 Notes: This missile was all but dropped from production by 2000 in favor of the less capable but far less costly AMRAAM.

Raytheon AIM-120 AMRAAM

     Notes:  The AMRAAM (Advanced Medium-Range Air-to-Air Missile) replaced the AIM-7 Sparrow in the inventories of the US and most of its allies in the late 1980s.  The project was begun by Hughes Aviation in the late 1970s, and selected in preference to a Raytheon missile; it has since been bought out by Raytheon. Low-rate initial production began in October of 1988, after a lengthy and trouble-fraught testing period that started in 1981. Full-rate production did not begin until 1991, though after that point, stocks of the AIM-7 Sparrow were replaced by the AMRAAM as quickly as possible on US and NATO aircraft.  Sales to other countries followed later in the 1990s. Though AIM-120s were carried by aircraft in Desert Storm, none were fired at enemy aircraft; first kill for the AMRAAM, of a MiG-25, occurred in December of 1992 during Operation Southern Watch, the US patrolling the no-fly zone over Iraq.

     The AMRAAM is an advanced, active-homing radar-guided missile with its own radar unit in the nose to allow it to be guided without help from the firing aircraft or ground unit once it’s own radar has acquired a fix on the target. This also helps it to resist countermeasures, the missile can actually home in on a source of radar jamming (Accuracy becomes difficult in this case); this is called home-on jam capability.  Decoying this missile with various radar countermeasures is two levels harder than normal.  The missile, as stated, does require an initial fix from a ground unit or aircraft radar; the missile begins self-guidance after traveling 2 kilometers (2000 meters).  The ground unit or aircraft that gives the AMRAAM the initial radar lock-on does not have to be the same as the firing unit or aircraft, as long as a data link exists between the unit or aircraft locking on and the unit or aircraft firing the AMRAAM.

     The initial version, the AIM-120A, is still in use by the US and NATO as well as other countries, though many US and NATO aircraft carry later iterations of the AMRAAM.  The AMRAAM is capable of being carried on pylons otherwise used only by the AIM-9 Sidewinder, including wingtip launchers such as those on the F-16 and F/A-18.  The AIM-120B, first delivered in 1994, uses an improved guidance system, though inside a standard AIM-120A body.  The AIM-120C, first delivered in 1996, has as it’s primary difference clipped fins; the AIM-120C was designed specifically for carriage inside the F-22 Raptor’s weapon bays, though it can and is used by other aircraft.  The guidance unit is further upgraded (though not measurable in Twilight 2000 v2.2 terms).  The AIM-120C-4, delivered in 1999, uses an improved warhead.  The AIM-120C-5, delivered in 2000, is equipped with a larger, more powerful motor, more miniaturized electronics, and an ECCM upgrade (decoying this version is three levels more difficult than normal). The AIM-120C-5’s warhead is also smaller, though it throws a larger fragmentation pattern. It was quickly followed by the AIM-120C-6, which has an improved Target Detection Device (TDD); it only has to travel 1500 meters before its own radar takes over and no longer needs ground or aircraft guidance.  The AIM-120C-7 began delivery in 2006; this has increased range, improved ECCM, and an improved seeker (not measurable in Twilight 2000 v2.2 terms). (This version was requested by the US Navy, who was looking for a partial replacement for the long range they lost with the AIM-54 Phoenix.) 

     The AIM-120D is in the works; it has a two-way data link so that the firing unit or aircraft can make course corrections if needed (such as if the target maneuvers out of the missiles seeker angle or loses lock due to countermeasures). In addition to radar-homing, the AIM-120D has the assistance of GPS in tracking its target (though GPS is not nearly as effective against a fast-maneuvering target, let alone a moving target; it does give the missile a roll of 10 on a d20 to immediately regain a lost lock-on).  The AIM-120D can be fired from High-angle Off BoreSight (HOBS capability); the seeker head has a 120-degree field of “vision.”  Range is greatly increased; the rocket engine has been enlarged due to further miniaturization and increased in power due to increases in technology.  First delivery was expected for 2007, but the program has slipped quite a bit, and fielding has only just begun.

     In March of 2021 (exact date unknown), an F-15C fired a test version of the AIM-120D to an unprecedented distance to kill a violently-maneuvering BQM-167 subscale drone, capable of maneuvering at up to 9 Gs, and controlled from the ground with an option for autonomous flight.  This happened at the Eglin-Gulf Test and Evaluation Range.  Exact Details have not been released, but I think I can parse out enough details to stat something here.  The modified AIM-120 has been cited by a number of sources (each of which has a different theoretical range) of having hit the drone at anywhere from 160-240 kilometers (some say that the test AIM-120’s range approaches that of the AIM-54 Phoenix), and the F-15C had a new radar set installed to allow lock-on and radar detection at this range. The fact that the F-15C needed upgraded radar would tend to indicate that the test AIM-120 could fly to the outside of those possible ranges.  The test missile did not actually have a warhead; most missiles fired at drones for practice don’t actually have a warhead; instead, the drone registers that it has been hit by how close the missile passed, and if the pass is inside it’s kill radius, and if the missile registered that it was close enough to detonate the “warhead.”  I would assume that an actual service version of the test AIIM-120 could carry a standard AIM-120D warhead. Just to confuse the issue for adversarial countries, the test missile was fired during a WSEP event, in which there were several aircraft firing at drones.  The test AIM-120 is said to be heavier than a standard AM-120D, and the electronics are further miniaturized to reduce weight and make even more room for propellant. The propellant itself has been cited in some sources as being “denser” that that of an AIM-120D.  However, the stats below come down mojo and fudge, are highly theoretical, and highly subject to change.  The designation I’m using (AIM-120D-5) is not the actual designation (it’s supposedly called something like the “AIM-120 Test and Evaluation Missile”).

     The AMRAAM is also in advanced testing for use as a SAM.  This is known as the SLAMRAAM (Surface-Launched AMRAAM) or sometimes the HUMRAAM (HMMWV-launched AMRAAM) by the US Army and is also being tested by the US Marines.  This system uses a quintuple missile launcher on the back of a HMMWV, and uses a small acquisition radar on a separate vehicle or ground tripod. Most of this development has been done with the AIM-120A, though other AMRAAMs can be used; no major modifications to the AMRAAM are necessary. SLAMRAAM was to be fielded starting in 2008, but the project deadline has slipped considerably. The SLAMRAAM has received a designation of RIM-120 in some sources, though this designation is not considered official.

     Before this, as early as 1995, a joint US/Norwegian project called CLAWS (Complementary Low-Altitude Weapon System) was tested, launching AMRAAMs from modified HAWK SAM launchers (eight AMRAAMs per launcher), but CLAWS was cancelled in 2006.

     The NCADE is a test project which has still to bear fruit; it is an anti-ballistic missile version of the SLAMRAAM.  The seeker head is replaced with that of the AIM-9X, with two-way data link capability to enable ground or shipboard units to make course changes if necessary. A second stage is added to the basic AMRAAM to increase range and acceleration.  It is intended as a shorter-range solution than missiles such as the Patriot.  So far, no project date completion plans have been announced and details are lacking, and it will not be covered further here.

     Note that in Dale Brown’s book series, the AIM-120C is called the Scorpion.  This is not an official designation for the AIM-120C.  Any ground-launched systems listed above will be statted in the appropriate section.  It should be noted that the AMRAAM is slated to be replaced by the AIM-260 JATM, possibly by 2026 to begin to replace the AIM-120.

     Twilight 2000 Notes: In the Twilight 2000 timeline, the AIM-120A and AIM-120B were the primary radar-homing AAMs for the US, NATO, Saudi Arabia, South Korea, and Japan at the start of the war.  (They were more and more replaced by AIM-7 Sparrows as stocks of the AIM-120 ran short.)  The AIM-120C is a rare version of the AMRAAM, and the AIM-120C-4 was only just entering service at the start of the Twilight War; only the US had them, and perhaps less than 50 were available.  No other iterations of the AIM-120 were available in the Twilight 2000 timeline.