politically determined at the Presidential level. The ROE prohibited use of the Sparrow at medium/Beyond-Visual- Range (BVR) distances where it was capable of destroying an enemy target with little risk to the launching aircraft. (BVR meant greater than 20nm./36km. Pilots prefer to think in terms of a missile's 'no escape zone,' an ever- changing teardrop-shaped volume of space with dimensions that are classified.) This forced crews of the heavy F-4 Phantoms that used the Sparrow to close to visual range with the more agile North Vietnamese MiGs, making it nearly impossible to maneuver the big fighter's radar onto the nimble enemy interceptors.
And then the firing sequence was a nightmare. The AIM-7E2 version of the Sparrow III, used throughout the Vietnam War, had over ninety electrical, pyrotechnic, and pneumatic functions that had to work perfectly in the proper order, and took over three seconds just to get out of the launch well and on its way to the target. If that was not bad enough, the AWG-10 radar system on the U.S. Navy F-4J was roughly comparable in parts count and design complexity to the Surveyor-series of unmanned moon probes launched in 1966. And the lunar probe only had to function in the relatively benign vacuum environment of the moon for a month or two. The AWG-10 had to function after being slammed around repeatedly by catapult takeoffs and carrier landings in tropical conditions. As a result, the Sparrow III, as well as the radar systems of the various models of F-4s, had severe reliability problems. The Project Hot Shot engineers had never anticipated the possibility that AIM-7 missiles and their associated black boxes might be catapulted off aircraft carriers and do arrested landings three times a day in the steaming heat of Southeast Asia for weeks on end. In short, nobody had anticipated the nature of air warfare in the real world, and the Sparrow AAM was one of the victims of that lack of vision.
In short, it would be nice to say that the radar-guided Sparrow has been as successful as its heat-seeking cousin, the AIM-9 Sidewinder. But it would be a lie. The AIM-7 has been a disappointment, despite tens of billions of dollars spent on it and its fire control radars. When it is used properly, and the breaks go its way, it can be the most deadly of AAMs. But its designers promised a 'silver bullet,' and it never delivered, proving that no matter how much money you throw at a program, basic design limitations cannot be overcome. Some of the technologies the AIM-7 was based on were just fundamentally flawed. Nevertheless, the Sparrow has served for five decades, and continues to soldier on, periodically improved and updated. It became a primary weapon of the F-15 Eagle, and is carried on most other U.S. and NATO fighters capable of air-to-air operations (such as the U.S. F-14 Tomcat and F-18 Hornet). Slowly and painfully, shortcomings and problems were overcome, at a cost of billions of taxpayer dollars. Finally, some forty-five years after it was conceived, the Sparrow III got its day in the sun during Operation Desert Storm. The good news was that the final major version of the missile, the AIM-7M, shot down more Iraqi aircraft (twenty-four) than all other weapons combined, and that it was over four times as effective as it was in Vietnam. (In Vietnam, the AIM-7 had a success rate of about 9 %, while in Desert Storm, depending how you interpret the data, it was about 36 %.) The bad news was that almost half the AIM-7s launched failed to function properly, and only about one Sparrow in three actually hit and killed anything. Out of seventy-one AIM-7Ms fired in Desert Storm, only twenty-six hit their targets, for twenty-three kills. It was as good a performance as the Sparrow ever gave, and it stank. Luckily, there was already a replacement on the way.
Vietnam was a wake-up call for the fighter community. They didn't have the right weapons for the job; and that stung them. Then it took several more years, and more proposed Sparrow variants, for the truth to finally hit home. They needed a new BVR missile. The argument for a radically new missile was simple. If an enemy fighter force with an all-aspect, IR missile faced off against a U.S. fighter force using Sparrow, the U.S. force might barely break even in the critical kill/loss ratio that separates victory from defeat.
Thus came a specification for a new kind of BVR missile: It would have the same fire-and-forget capabilities as Sidewinder, but much greater reliability and speed; it could be carried on much smaller fighters than the Sparrow; and it would throw away the concept of 'maximum range' for a more useful and deadly measuring stick — the no-escape zone. No escape means that any target aircraft inside the new missile's performance 'envelope' would be unable to get away, no matter how hard and fast it punched the afterburner or how violently it maneuvered. Because the AIM-7 series had neither the brains nor the energy for such sophisticated maneuvering, it was relatively easy for a skilled pilot to evade, especially with the warning that even a primitive RWR provided.
Five different manufacturers vied for the opportunity to build the Advanced Medium Range Air-to-Air Missile, or AMRAAM. In 1979, the competition was whittled down to just two contractors: Raytheon Corporation and Hughes Missile Systems. After two years of development and competition, Hughes won the biggest AAM contract of the century in 1981. The contract was for twenty-four developmental missiles with options for production of an additional 924, and plans for up to 24,000. The missile, designated as the AIM-120, would take almost a decade to bring into service.
Hughes brought strong credentials and a wealth of experience to the problem of developing AMRAAM. They were builders of the long-serving AIM-4 Falcon series of AAM, and the most powerful AAM in history, the mighty AIM-54 Phoenix. Phoenix, which came into service in 1974 on the Navy F-14 Tomcat fighter, was the first true 'fire- and-forget' radar-homing AAM, and has been the airborne shield for the fleet for over two decades. Known as 'the buffalo' by the fleet aircrews for its impressive size and weight, Phoenix has a range of up to 100 nm./182.9 km. and the ability to engage multiple targets with multiple missiles at the same time. One of the key objectives of the AMRAAM program was to give pilots of single-seat fighters like the F-15 and F-16 the same kind of firepower and tactical capabilities as the F-14 Tomcat, with its two-man crew and powerful AWG-9 radar /fire control system. It would be a technical challenge to pack so much performance into a much smaller airframe.
Unfortunately, the AMRAAM program ran into terrible technical problems. For years, AMRAAM development and testing failed to go smoothly, mostly because everything in the AIM-120 was generations ahead of the best technology on the Sparrow. The advanced electronics, structures, and rocket motor were difficult to design, qualify, and produce. The real hang-up, though, was the software. The AIM-120 is driven by microprocessors running hundreds of thousands of lines of computer code — more than any AAM in history. After each line of code is written, it has to be validated through rigorous testing. Any faults or problems have to be isolated and fixed, and then the process begins again. This cycle continues until the code is ready to be loaded on tape cassettes for delivery to units equipped with AMRAAM. If this sounds frustrating, try to remember the last time a commercial software program 'bombed' on your computer. You probably lost an hour or two of work, rebooted, and drove on, muttering a curse on the programming 'geeks' who left the bug in the code. But in a system like an AAM, the software has to be
Then, some good things began happening. Fully validated software tapes began to arrive at test sites, and missiles began to fly straight and true against their drone targets. To some of the missile's critics, it appeared that a miracle had happened. In fact, AMRAAM had followed the normal path of a system controlled by computers and software. It is a hallmark of software-driven systems that they are virtually useless until a valid version of the software is available. But when the day comes that a technician plugs in the final release version of the software, it usually works exactly as promised. Like the Army's Patriot SAM and Navy's Aegis Combat System, AIM-120 came of age when its software was finally ready. The final validation of AMRAAM came at the White Sands Missile Range when an F-15C ripple-fired four test AIM-120s at four jammer-equipped QF-100 target drones, maneuvering aggressively and kicking out flares and chaff decoys. Dubbed the 'World War III Shot' by test directors, it resulted in all four drones going down in flames. All of the Congressionally mandated tests were passed.
With the problems of testing behind, the first production missiles began to be delivered in late 1988, becoming operational in 1991 when 52 AIM- 120As deployed with the F-15Cs 58th Tactical Fighter Squadron (TFS) of the 33rd Tactical Fighter Wing (TFW) to the Persian Gulf, in time for the end of Desert Storm. As it turned out,
