Aerospace America
January, 1990
Radar combat and the illusion of invincibility
by Jeffrey L. Ethell, Contributing Editor
Evidence mounts that the stunning capabilities of radar guidance may prove to be its greatest liability
Ever since World War II proved the stunning capabilities of radar, military planners have come to depend on it more and more in modern combat. At present, the U.S. builds weapons and trains personnel in preparation for the radar war of the future, relying almost exclusively on the combat advantages of radar-guided missiles, radar-avoiding stealth technology, air- and land-based early warning radar, low-level terrain-following radar, and target acquisition radar.
At the heart of radar's performance is an uncanny ability to find and hit targets at distances beyond enemy killing range, primarily beyond visual range (BVR). At the same time, radar can be used to provide early warning of an enemy's intentions while radar-jamming and stealth techniques can help to avoid detection by enemy radar. It is almost as if radar has become a kind of Rosetta Stone for the practice of modern warfare.
Unfortunately, radar has not only turned out to be less than invincible, it has recently become a liability. Fueling what is now a raging debate are the last few shooting engagements in the Middle East: The USS Stark could not defend itself against two Exocet sea-skimming missiles; USS Vincennes Aegis cruiser fired BVR at what its crew thought was an attacking fighter and downed an Iranian airliner; and two F-14s fired twice at intruding Libyan fighters, missing them BVR with radar-guided Sparrows and shooting them down within visual range with a Sparrow and a heat-seeking Sidewinder.
The DOD has been trying since 1977 to give birth to the advanced medium range air-to-air missile (AMRAAM) as a replacement for the AIM-7 Sparrow and the AIM-9 Sidewinder. Almost 13 years later, the technical challenges of creating the AMRAAM are still to be met. One of those responsible for developing the missile in the Office of the Secretary of Defense, Charles E. Myers, says "the drive to create it was a reflection of the frustrations in the radar weapons community."
The dogfight was consigned to the scrapheap of history when radar-guided missiles appeared in the '50s. Guns disappeared from from fighter planes, and missiles were hung in their place to defend U.S. borders and naval vessels from air attack. Sorting friend from foe was never considered worrisome, even at the higher closing speeds of jet aircraft and greater firing range of the airborne missile. Then came Vietnam and what one-time combat pilot Myers calls "military-political gymnastics" instead of a real air war.
Suddenly, a minor enemy arose who put up a limited air challenge with inferior MiGs. The U.S. fielded its front-line fighters, in particular the F-4 Phantom II, which had been designed for fleet defense rather than violent close-combat aerial maneuvering. Back came the dogfight, but since pilots had little dogfight training and worried about killing their buddies, the Americans did not do well, especially with radar-guided Sparrows and especially beyond visual range.
Even though Vietnam drove home the lesson that pilots and aircraft must learn to dogfight within visual range, the air services asked for improved radar missiles. The AMRAAM emerged, supported by advocates inside and outside the DOD. To score a kill during a swirling dogfight, a pilot would have to launch missiles one after the other at multiple targets, a dubious tactic quickly called "launch-and-leave." "What no one wanted to say," says Myers, "is that they already had a missile that did this -- the cheap, accurate heat-seeking Sidewinder."
At $ 500,000 a missile, the AMRAAM solution has a cost 10 times higher than a Sidewinder. It is so expensive that the services have been forced to stop buying the Sidewinder because they can no longer afford both radar-guided and heat-seeking missiles.
In the AMRAAM project office, Air Force Col. James Burton had been handed the job of collecting hard information on the effectiveness of missiles in air-to-air combat. Burton studied all 407 known missile kills made in the air since 1958 (except for the 1967 Middle East war and Pakistan's 1971 clash with India), focusing hard on the 2,014 missile firings made during the Vietnam War and the 1973 and 1982 Middle East skirmishes.
Burton fast became one of the most unpopular men in the Pentagon. He titled the briefing he gave on his findings "Letting Combat Results Shape the Next Air-to-Air Missile." His findings? Of more than 260 Arab aircraft knocked down by Israel in 1973, only five fell to Sparrows in 12 firings. Of the 632 Sparrows fired in all the wars Burton studied, only 73 destroyed the airplane they were fired at, for a kill rating of 11%. The ancient Sidewinder did almost three times better: of some 1,000 Sidewinder firings, 308 kills resulted in a kill rating of 30%.
In Southeast Asia, Sparrow had such a poor reputation that pilots routinely ripple-fired their Sparrows, firing off two or more in a row rather than taking a chance on a single shot. Even though few fighters came to Vietnam equipped with guns, they had a better kill rating than Sparrow-equipped fighters. Burton found that guns actually made about one-third of all the kills counted in Vietnam.
To the horror of those he briefed, Burton told them he found only four BVR kills in all the wars he covered. What is more, each of the four (two by Israel, two by F04s in Vietnam) was carefully staged outside the confusion of combat to prove BVR's combat worthiness. One Southeast Asia kill was listed as a MiG-21 when it was really an F-4 mistakenly identified and shot down using Combat Tree, the BVR identification equipment of the era that was supposed to sort friend from foe. According to Burton, the only reason Israel went after its two BVR kills was strong pressure from the U.S. to establish BVR doctrine.
In summarizing how the 407 missile kills were made, Burton came up with some unsettling conclusions:
* Most targets were unaware and were fired on from the rear.
* An insignificant number of targets were aware and maneuvered hard to avoid the attack.
* Many rear shots were fired from above the target, making them more difficult shots to hit.
* There were almost no head-on BVR shots because of the high closing speeds of the aircraft involved.
Even though BVR shots were almost nonexistent in the wars Burton studied, he reached one unsettling conclusion: "The most dominant aspect of missile air combat to date has been the requirement to positively identify the target." And the only sure way to do that has been by eye.
When validation tests were under way in the late '70s, on the air combat missiles and doctrines of the next generation, the cry went up that the results would be useless since most of the flying was done under clear air visual conditions and BVR shooting was so limited. Myers suggested giving AMRAAM's proposed operational BVR parameters and air-to-air anti-radiation missiles (ARMs) to Red Force. This would give everybody some rules and results worth measuring, but the idea was struck down by the AMRAAM office. Clearly, the new rules might have pointed up radar's inherent weakness: A simple, inexpensive missile like ARM can home in on radar and kill in an instant.
In 1984, Burton managed to have the idea tested in McDonnell Douglas' differential maneuvering simulators. The results were devastating. Over and over, ARM-equipped fighters shot down AMRAAM aircraft and missiles. The results were turned over to the AMRAAM office, which invalidated them and threw out the exercise. In airborne tests in Nevada, Red Force aircraft using simple radar homing and warning devices could see Blue Force AMRAAM radars coming on 10 mi. away. The warnings allowed Red Force to turn away and beat the missile. When the AMRAAM radar was reset to come on 5 mi. from the target aircraft, the change negated the longed-for BVR scenario.
In addition, the missile's fabled multiple-target tracking and killing capability turned out to be no more effective than single-target shooting, either in simulations or live aerial firings. "The simple launch-and-leave ARM casts a pall over the whole issue since it homes in perfectly on an illuminating radar," says Defense Dept. analyst Thomas Amlie. "This means you can't use AMRAAM, AIM-7, Phoenix, or any other radar-guided missile in combat."
Meanwhile, the USSR has a well-developed series of ARMs, including the AA-10 Alamo for air-to-air combat. They have also converted the AS-4 Kitchen and AS-6 Kingfish, both with 2,200-lb warheads, into ARMs. Notes Amlie: "They never throw anything away. Flying at Mach 3+, these are a tremendous threat to the U.S. fleet, which is virtually bathed in radar. Now our prime weapons systems, such as Aegis, STARS, E-3A, Patriot, and Hawk, are in serious jeopardy."
Targeting the enemy has never proved difficult for the Soviets, especially with American fighters. "All fighter radars in the U.S. transmit on the same frequency, right around 10,000 MHz, to get all-weather capability," Amlie says. "That is very convenient, a missile designer's dream. The Soviets have no need for IFF transponder identification since their radar frequencies are higher or lower, so ARM use is almost risk free, even in a mixed air-to-air fight." As soon as U.S. pilots turn on their radars, the opposition gets some valuable information as well -- how many fighters are out there, their nationality, their direction, whether they are locked on to fire, and type of fighter -- based on their radar pulse signature.
The pilot firing the ARM still has problems, such as obtaining distance from the target, the need for his own radar to paint the target and give its range, the possibility of the ARM homing in on multiple enemy and friendly radars in the air, ground, and sea, and the very strong possibility of homing in on decoys. Regardless, the mere presence of ARMs in the air can lead to everyone turning off their radars, which puts the real combat arena squarely back into the visual, maneuvering, close-up fight that, AMRAAM supporters say, is not likely to happen because of the "reality" of BVR combat.
In 1969, the DOD tried to test an air-to-air ARM developed from the Sparrow airframe under the project name Brazo. At modest cost, three test firings destroyed three target drones. Amlie says the program "was cancelled when it could be interpreted as eliminating large radar fighters such as the F-14 and F-15, since the tests proved you could not use a radar fighter in combat when up against ARMs. The only countermeasure was to turn the radars off, so everything was swept under a rug." Now, department rumblings suggest that development of an air-to-air ARM is again under consideration.
The host of U.S. radar-based weapons are all vulnerable to ARMs. The E-3A AWACS has a superb radar antenna that can detect hundreds of targets simultaneously -- and can itself be seen at extremely long distances. An AS-4 or -6 could be launched 300-400 mi. away and home in on it with ease. The same is true for the 40 Aegis cruisers and destroyers destined for fleet service with the Navy. With hundreds of Soviet ARMs ready for firing from submarines, surface ships, aircraft, and land, a U.S. carrier battle group, heavily dependent on radar, might be in serious trouble, especially if the missiles were sea-skimmers.
At best, Navy countermeasures are limited against so simple a weapon. Sea-skimmers pop up over the radar horizon a bare 14 mi. away, and when radar does detect the missile, the radar reflections bounce off the waves, making it difficult to determine altitude, thus throwing off tracking. A third Soviet line of attack comes from their radar jammers, among the world's most powerful.
Pilots of B-1 and B-2 bombers penetrating Soviet airspace most likely will use terrain-following radar to stay low and avoid detection. Using inexpensive radar finders, like the fuzzbusters motorists use to avoid police speed traps, on hiss surrounded by flat terrain, the Soviets should have no trouble seeing the bombers coming. And Soviet radar homing and warning equipment can pick up VHF transmissions or over-the-horizon radar from distant approaching aircraft. In fact, the whole issue of stealth technology could become moot, if one considers that a radar antenna runs along the entire length of a B-2 wing's leading edge. Once in visual range, stealth is irrelevant. It is more than probable that an F-117 or a B-2 can be found, identified, and shot down using basic common sense. The F-117 has to make such wide turns that its survival in a visual air-to-air fight is precarious.
Myers, who proposed the first stealth aircraft ideas under Project Harvey (after the famous invisible rabbit), is extremely disappointed over where things have ended up. He recommended a small, inexpensive aircraft that would be hard to find with radar and eye. Yes, payload would have been small, but the idea was to confuse the opposition. "Suppose I weigh only 75 lb, with the payload of a hatpin, but I'm visible," he says. "How much trouble and chaos could I cause in the enemy camp?" A small aircraft carrying a small ARM and a gun, Myers' original stealth plane was to effectively blind the enemy by taking out radar vans and emplacements. The F-117 seems to have a similar mission, but had to be bigger to carry weapons like the Maverick missile as required by current Air Force doctrine.
Still, a growing number of soldiers and analysts are asking tough questions about the future of radar warfare. "We cannot go around radiating signals," says Amlie. "The French sell a missile to the entire Third World that will hit an Aegis every time. We are building a peacetime military that will never be effective in combat."
Oh, the gun has a sheath that hides the barrel normally (for reduced RCS), but obviously the sheath moves when firing. 
never saw such thing before...