On September 18, 2022, the United States Air Force celebrated her 75th birthday. Four or six days subsequent to this – the exact date varies from one account to the next – another anniversary of a significant military aviation milestone took place, although it received considerably less press: the first kill scored against an enemy aircraft in real-world combat by an air-to-air missile. The winning missile in question was the ubiquitous heat-seeking AIM-9 (“Air Intercept Missile-9”) Sidewinder.
The Sidewinder missile’s namesake is a species of rattlesnake (scientific name Crotalus cerastes) so-called because of its literal sidewinding gait which aids the animal movement across shifting sands and is the fastest-moving of all rattlesnake species. Like all rattlesnakes, the sidewinder has a venom known as hemotoxin – attacking the red blood cells – which can be quite deadly to humans; however, as the Atlanta Zoo website points out, “they are shy and mostly nocturnal, resulting in relatively few bites to humans.”
By contrast, the Sidewinder missile has no such shyness, can operate both day and night, and is specifically geared toward killing humans … or killing manmade flying machines anyway. Nonetheless, seeing as how the actual snake lives in a desert environment and uses infrared sensory organs to detect prey animals, it remains a fitting name for a heat-seeking missile.
Origins of the Flying Rattlesnake
As noted by an official U.S. Air Force fact sheet, “The Sidewinder was developed by the U.S. Navy for fleet air defense and was adapted by the U.S. Air Force for fighter aircraft use … The infrared guidance head enables the missile to home in on target aircraft engine exhaust. An infrared unit costs less than other types of guidance systems, and can be used in day/night and electronic countermeasures conditions. The infrared seeker also permits the pilot to launch the missile, then leave the area or take evasive action while the missile guides itself to the target…The AIM-9A, a prototype of the Sidewinder, was first fired successfully in September 1953. The initial production version, designated AIM-9B, entered the Air Force inventory in 1956 and was effective only at close range. It could not engage targets close to the ground, nor did it have nighttime or head-on attack capability. These shortcomings were eliminated on subsequent versions.”
Aerial Rattlesnake’s First Victims
As indicated earlier, it was in September 1958 that the Sidewinder obtained its first kills in aerial combat. However, the aerial victories were obtained by neither the U.S. Navy nor the U.S. Air Force … but rather Taiwan’s Republic of China Air Force (ROCAF), during the Second Taiwan Strait Crisis, over the Quemoy islands. In this engagement, the ROCAF pilots, piloting Korean War-vintage F86 Sabres, were able to get the upper hand against the superior on-paper Red Chinese-piloted MiG-17 “Fresco” jet fighters, using their newfangled AIM-9s to account for four out of the 10 MiGs shot down that day.
For the duration of that conflict, the ROCAF fighter pilots shot down 31 PRC Frescoes for the loss of only two Sabres, with the AIM-9 proving to be a significant difference maker; reports indicate that the Taiwanese Sabre drivers scored a 60 percent kill rate with the missile. However, the Law of Unintended Consequences also came into play during this conflict: in one instance, a Sidewinder struck a MiG-17 but failed to detonate, and the enemy jet safely returned to base, whereupon the missile wreckage was removed and later examined, resulting in the reverse-engineered Vympel K-13 (AA-2 Atoll) in the USSR and the license-built PL-2 equivalent in the PRC.
Alas, during the Vietnam War, American fighter pilots were not able to replicate the success with the Sidewinder that the Taiwanese F-86 pilots had, in spite of flying more capable warplanes such as the F-4 Phantom, F-8 Crusader, and F-105 Thunderchief; indeed, the kill rate dropped to a mere 10-15 percent! For one thing, U.S. aviators didn’t have the advantage of surprise (“shock and awe,” if you will), and the North Vietnamese Air Force (NVAF) pilots were able to adjust their tactics accordingly.
“Furthermore,” as noted by Dr. James Young in a Marine Corps University research paper, “the high altitudes of the fighters’ engagements maximized the contrast between the MiG-17s’ jet engines and surrounding atmosphere. Lastly, happenstance prevented any of the missiles from being launched in suboptimal conditions, such as with cloudy backgrounds or at an angle that allowed the Sidewinders’ seeker to inadvertently track onto the sun.”
So it was back to the drawing board for the Sidewinder’s R&D team. They came up with the AIM-9H version, which, along with improved tactics developed at the then-new “Top Gun” School, enabled the Navy to gain much better success by Operation Linebacker I in 1972, though still nowhere near the ROCAF 60 percent record.
AIM-9L and Beyond
Improvements on the missile continued. It was the AIM-9L variant that truly enabled the Sidewinders to achieve “their finest hour” (to borrow a Winston Churchill Battle of Britain phrase): in the 1982 Falkland Islands War, British Sea Harrier pilots attained a success rate of over 80 percent – a major reason behind their remarkable 23:0 kill ratio – against their Argentine adversaries; that same year, Israel Defense Forces (IDF) fighter pilots participating in the Lebanon War scored an even more astonishing kill rate of 85 percent against Syrian MiGs over the Bekaa Valley. The AIM-9L also worked well for American fighter pilots, in the 1981 Gulf of Sidra Incident and 10 years later during Operation Desert Storm.
The Sidewinder is still produced by Raytheon today, now as the AIM-9X variant, which has proven itself adaptable to 5th-Generation fighters such as the F-22 and F-35. It’s also proven itself adaptable to killing UAVs, as an F-15E Strike Eagle pilot demonstrated over Syria in August 2021.
In summation, the Sidewinder missile has embodied the truism that “Flexibility is the key to airpower.”
Christian D. Orr is a former Air Force Security Forces officer, Federal law enforcement officer, and private military contractor (with assignments worked in Iraq, the United Arab Emirates, Kosovo, Japan, Germany, and the Pentagon). Chris holds a B.A. in International Relations from the University of Southern California (USC) and an M.A. in Intelligence Studies (concentration in Terrorism Studies) from American Military University (AMU). He has also been published in The Daily Torch and The Journal of Intelligence and Cyber Security. Last but not least, he is a Companion of the Order of the Naval Order of the United States (NOUS). In his spare time, he enjoys shooting, dining out, cigars, Irish and British pubs, travel, USC Trojans college football, and Washington DC professional sports.