AIM-9E Sidewinder

   Created based on analyses of air combat reports in the Vietnam War, the second generation of the Raytheon AIM-9 Sidewinder were a product improvement of the AIM-9B and AIM-9D. These missiles were the mainstay of many air arms around the world for over 30 years.

   The first generation of AIM-9 Sidewinders had delivered mixed results in combat over Southeast Asia. While they were the most effective missile by far used by the US military in that theater, the short range and narrow azimuth of their seeker heads gave them much less utility than expected, and when stronger heat sources than the target entered their field of view (e.g., burning vehicles on the ground, factory smokestacks, and sun glare), Sidewinders would go after these instead. The Probability of Kill (pK) ratio was also far less than predicted, with Sidewinder launches only hitting targets 25% of the time in the most favorable reports (on average, the pK ratio of all Vietnam War Sidewinder launches combined was 10%) --- far from the promised 90%.

   The AIM-9E was developed at the behest of the US Air Force (USAF), making it the first Sidewinder variant created expressly for that service (the previous Sidewinders were all developed for the US Navy). Similarly, the AIM-9F was developed in Germany, making it the first Sidewinder variant developed by a foreign country. The AIM-9G and AIM-9H were both developed for the US Navy. While the E and F models were developed from the more common AIM-9B, the G and H were evolutions of the US Navy's distinct AIM-9D.

   The AIM-9E looks almost identical to the AIM-9B, with the obvious exception of a much longer nose. The general composition of the E~H Sidewinders is largely the same as those of previous missiles (see the AIM-9 page for a detailed description), though several components on some of these new models are different. For example, the AIM-9E has a more finely-tapered nosecone with a new seeker head, and boasts a new thermoelectric cooling system (also referred to as a "Peltier system") for the seeker. The importance of the new cooling system used by the AIM-9E cannot be overstated, as it allowed the seeker head to be cooled indefinitely until the missile was launched. The glass seeker window on the tip of the nosecone was replaced by a new example, made of magnesium fluoride, which has greater infrared transparency.

   All four of the second generation Sidewinders, including the E~H are infrared-guided, but their guidance was markedly improved over the first generation. In addition to a higher infrared resolution, the AIM-9E's seeker also boasts a faster 100 Hz reticle rate, and a 16.5 deg/sec tracking rate. It is less clear as to what changes were made with the AIM-9F's guidance system, though they reportedly resulted in an improved pK ratio. All four models still use the lead sulfide seeker element of the preceding Sidewinders.

   The motors used in nearly all of these missiles are the same as those from the AIM-9B (Thiokol/ Mk.17), and the AIM-9C and AIM-9D (Hercules Mk.36). The exception was the improved AIM-9E-2 variant, which boasted a reduced-smoke version of the Mk.17 that was co-produced by Aerojet. These all accelerated the AIM-9E~H to a speed of approximately Mach 2.5 (3 087 km/h), within seconds after launch, by which time the propellant has already been expended. The AIM-9H was also given an even further improved motor, made by Hercules Bermite, in the form of the Mk.36 Mod. 5,6, or 7 (depending on which phase of production a given AIM-9H was built in).

   The AIM-9E and F still retain the same warhead as the AIM-9B (HE-FRAG), and the AIM-9G uses the same warhead as the AIM-9D (Mk.48 continuous rod). An improved version of the Mk.48 continuous rod is installed in the AIM-9H. As with the preceding missiles in the series, these warheads were powerful enough that a single Sidewinder could potentially shoot-down any aircraft with a single direct hit.

   It is unclear exactly how many of these missiles were produced, as different sources have produced different claims.

   AIM-9E: ~ 5 000 units
   AIM-9F: No figure given
   AIM-9G: 2 120 ~ 20 000 units
   AIM-9H: 3 000+ ~ 7 700 units

   It would therefore seem that the exact production figures for these four Sidewinder models have thus far eluded the public, as these publications are in strong disagreement.

   It is also unclear how many AIM-9F Sidewinders were produced, and no internet sources present an exact figure (if they have any at all). They were all converted from European-built AIM-9Bs that numbered some 15 000 in total, so no more than that many could have been converted, but the number is still unclear; many AIM-9Bs would have been expended disposed of, or lost by then, and some air arms might have preferred not to convert their AIM-9Bs for some reason (e.g., budgetary constraints, too few remaining, skipping the AIM-9F for a later variant, etc.).

   As with the AIM-9B Sidewinder, the E, F, G, and H models were very long-lived in operational service. Exactly how long they've remained in service is unclear, through given that some air arms still use the AIM-9B, some of these four newer missiles are probably still operational as well.

   The AIM-9E saw some combat use in Southeast Asia, achieving 6 confirmed kills.

   The AIM-9E, AIM-9G, and AIM-9H were all rebuilt by Philco-Ford Aerospace, with considerable assistance from Raytheon. The AIM-9F was produced in Germany by BGT (Bodensee Gerätetechnik), predominately for sale to NATO air arms.

   Production of all four of these missiles ended by the mid-1970s, and any remaining serviceable examples are nearing their expiration dates. They are no longer available for production, and assuming any of them are still available for export, they are probably only worth their scrap value.

Variants

   AIM-9E Sidewinder: Upgraded AIM-9B for the USAF, with an improved seeker head. Around 5 000 AIM-9Bs were converted into AIM-9Es.

   AIM-9E-2 Sidewinder: Same as the AIM-9E, but with a reduced-smoke motor.

   AIM-9F Sidewinder: European development of the AIM-9B, similar to the AIM-9E, but with a different seeker head. It was developed by BGT in Germany. Most European AIM-9Bs were converted to AIM-9F standard.

   AIM-9G Sidewinder: New missile based on the overall design of the AIM-9D, but with an improved seeker head.

   ATM-9G Sidewinder: Captive air training version of the AIM-9G. It has ballasts in place of the engine and warhead, and is used in training exercises to lock-onto other aircraft in mock dogfights.

   AIM-9H Sidewinder: This is basically an AIM-9G with substantial reliability improvements. The AIM-9H introduced solid state electronics, an improved warhead, and a thermal battery (which replaced the turbo-alternator used in the AIM-9D). The AIM-9H was also given an improved motor, made by Hercules Bermite, in the form of the Mk.36 Mod 5,6, or 7 (depending on which phase of production a given AIM-9H was built in). An improved version of the Mk.48 Continuous Rod is installed in the AIM-9H. This missile has a virtually identical exterior to that of the AIM-9G. It entered service with the US Navy in 1972.

   ATM-9H Sidewinder: These are basically ATM-9Gs upgraded to carry the seeker head of the AIM-9H.

Similar weapons

   R-13: Designated AA-2C or Atoll by the West, this is an improved version of the preceding R-3S (Western designation AA-2) missile, which was a direct duplicate of the AIM-9B. The R-13 itself was developed from a reverse-engineered AIM-9D, but enough modifications were made that it visibly differs in appearance. However, it is closer in performance to the AIM-9D, than to the E, F, G, and H models.

   R.550 Magic: A contemporary of the AIM-9H, the French R.550 Magic is broadly similar to the Sidewinder, but is immediately distinguished by having two tandem sets of forward fins. A notable internal difference is its seeker element, which is cryogenically cooled with liquid nitrogen. Being shorter and lighter than the Sidewinder, and having a larger fin area, the Magic is likely much more maneuverable than the AIM-9H as well.

   Shafrir-2: A rapid follow-up of the Shafrir-1 missile (which was immediately deemed a failure), Israel's Shafrir-2 became operational too late for the Six Day War or the War of Attrition, but it earned great fame in the Yom Kippur War --- and 89 confirmed kills. It is broadly similar to most Sidewinders, but visibly shorter at 2.5 m, and fatter with a fuselage diameter of 150 mm.

   TC-2: This Taiwanese missile is very close in capabilities and attributes to the AIM-9H, but it is slightly smaller. However, as the TC-2 was introduced in the mid-1980s, it was largely obsolete even before its debut. The "TC" in its name is short for Tien Chien, or "Sky Sword", which is also an alternate title for this weapon.

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