A heat-seeking surface-to-air missile hurtles skyward faster than the speed of sound. In a matter of seconds, it can zero in on a plane, blasting it from the sky in a sickening burst of flame and smoke. Moreover, such missiles are all too available to terrorist groups and criminals around the world. Last week intelligence reports indicated that the Colombian cocaine cartels may be stockpiling just such antiaircraft devices. The fear is that the drug lords could use them to mount an attack on President George Bush when he flies into the Colombian city of Cartagena for a four-nation antidrug summit starting Feb. 15.
Could the President's plane be shot down? Military experts say the chances of a guerrilla group mounting a successful air attack on Air Force One are extremely small. Although the exact nature of the plane's defenses is top secret, they are known to be formidable. Not only can the President's Boeing 707 be protected by a full complement of military fighter jets but the plane is also loaded with sophisticated electronic safeguards.
The heart of the defense rests in a collection of computerized equipment mounted in the 707's cockpit. There, at a console packed with indicator lights and video monitors, a specially trained electronics war officer can monitor the airspace around Air Force One. Should danger be indicated, he can unleash several electronic countermeasures, including radar jammers, fine-tuned infrared flares and billowing clouds of metallic chaff.
The most serious threat comes from surface-to-air missiles (SAMs) launched either just before the President's plane lands or just after it takes off. Although the Colombian drug cartels have apparently never used such weapons before -- and there is still no hard evidence that they have acquired them -- there are certainly plenty of SAMs, primarily U.S.-made Stingers and Soviet-built SA-7 Grails, available through illegal channels. Both are portable, shoulder-mounted rockets that use tiny infrared sensors to home in on the heat generated by a jet engine.
The standard defense against a heat-seeking missile is to divert it with another heat source, typically a flare that emits a broad range of infrared radiation. The missile, drawn by the heat of the flare, follows it and not the plane. But modern SAMs are equipped with filters that can cancel out radiation from a simple flare. Air Force One is believed to carry flares that burn brighter and longer in the infrared frequencies that the SAMs' sensors follow.
But not all missiles are heat seekers. Air Force One must also be protected against radar-directed air-to-air missiles, like the French-built R-530s that Colombian air force jets are known to carry. These rockets spot their prey with radar beams and follow the echoes toward the target. One way to divert a missile flying along a radar beam is to fire off a burst of metallic chaff particles. They cause the missile's radar guidance system to go haywire amid a blizzard of electronic gibberish.