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During Desert Storm, most fighters packed Sidewinders: F-16s armed with the missiles await the next mission. (USAF/TSGT Fernando Serna)

Sidewinder

The missile that has rattled enemy pilots since 1958.

Rockets serve a lot of useful functions, but shooting down airplanes isn’t one of them, a truth demonstrated all too clearly in 1956, when a pair of F-89 Scorpions fired 208 rockets against a wayward drone that was threatening southern California, and failed to score a single hit. After World War II, various military contractors developed nearly a dozen guided missiles. The most promising guidance system seemed to be radar, which was, after all, a proven technology. But because the equipment was too bulky to fit inside a rocket, the airplane firing the missile had to “paint” the target with radar, and the pilots had to stay locked on until the warhead detonated.

McLean had a better idea: Why not create a weapon that carried its own control system, so the missile was guided by the target? This led him to investigate the use of an infrared seeker to detect the target’s heat. McLean wanted to give a conventional rocket—a dumb weapon—eyes and a brain. The missile would “see” via a transparent seeker head, through which infrared radiation from the exhaust of a jet engine would reflect off a gimballed, rotating mirror onto a lead-sulfide photocell. As the gyroscopically stabilized mirror moved to track the heat source, a servo motor manipulated the canards that controlled the missile’s flight, maintaining a constant bearing with respect to the target. Proportional navigation, as the technique is called, enabled the missile to anticipate where the target was going to be rather than aiming at where it was, like a quarterback leading a receiver.

Compared with radar-guided missiles, McLean’s alternative was cheap, simple, and robust. Also, unlike radar guidance, it was a passive weapon that gave the targeted pilot no warning until he saw the missile flying toward him. Small, lethal, and able to strike quickly and outmaneuver its quarry, it shared several qualities with another heat-seeking predator native to the Mojave Desert: the sidewinder rattlesnake. So in 1950, another proposed name—Low I.Q. Homing Head—was rejected, and Sidewinder was adopted.

There was no official backing for the project, and on several occasions it was nearly canceled. But the tiny team working on the Sidewinder was persistent as well as ingenious, and the engineers, faced with seemingly intractable problems, developed a host of elegant solutions. A good example was the so-called rollerons: spur-like discs that unlocked from the tail fins in flight. The gyroscopic effect of the spinning discs prevented the missile from rotating on its axis. And then there was the famous Sidewinder tone, a menacing growl—once heard, it is never forgotten. During early flights, test pilots had to check a small voltmeter in the cockpit to determine whether the seeker was sensing a heat source, an unwanted distraction in the middle of a dogfight. By running an additional wire to the missile, the Sidewinder team was able to create a sound that could be piped into pilots’ headsets to alert them that the seeker had acquired a target.

Tom Amlie worked on the Sidewinder project as a young Navy lieutenant, and he later became technical director at China Lake. He says the secret of the missile’s success is simplicity: “In flight, it had seven vacuum tubes and five moving parts. The competition [Falcon] was complicated almost beyond description.” For professor Ron Westrum, the author of Sidewinder: Creative Missile Development at China Lake, the project demonstrated the triumph of lean R&D and imaginative management. “They had less than 25 people in the beginning, and they did it as a bootleg project,” he says. “The Sidewinder demonstrated that what we now call a skunk works actually works.”

Well, not at first.

Several years of development passed before the missile was ready to be fired in a simulated combat environment. In August 1952, astronaut-to-be Wally Schirra, flying an AD-4 Skyraider, launched a heat-seeker toward a propeller-driven Grumman F6F Hellcat that had been turned into a radio-controlled drone. Final score: Hellcat 1, Sidewinder 0. In fact, all 12 of the first Sidewinders missed the target. On several tests, Amlie flew in the right seat of the attack aircraft. After one failure, he wrote a memo quoted by Elizabeth Babcock in her history of China Lake, Magnificent Mavericks: “Missile took off like a big-assed bird, never saw it again.”

The 13th test, on September 11, 1953, was the charm. The Sidewinder fired by Lieutenant Commander Al Yesensky missed the drone by two feet, but if the missile had been equipped with a warhead and a proximity fuse, it would have destroyed the Hellcat, so the shot was declared a success. Four months later, an unarmed Sidewinder scored its first direct hit, punching a hole through the number 1 engine of a QB-17 drone. Then, on February 17, 1954, the Sidewinder did the unthinkable: It brought down—in cartwheeling flames—another QB-17 thought to be indestructible because it had survived so many missile attacks over the years.

The Sidewinder had shown its fangs.

CONVENTIONAL MILITARY WISDOM circa 1967 held that close-in dogfights were a relic of the past. Radar-guided AIM-7 Sparrows, developed by Sperry Gyroscope and Douglas Aircraft and first deployed in 1958, were supposed to take out bogeys while they were still miles away, and if that didn’t work, AIM-9 Sidewinders would finish the job long before enemy pilots got close enough to fire cannon. Thus, the F-4B Phantom wasn’t even equipped with a gun. Which meant that Navy Lieutenant Denny Wisely couldn’t do anything other than give his North Vietnamese adversary the finger as they passed canopy to canopy in the airspace near Hanoi.

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