Shoulder-fired anti-aircraft missiles, or MANPADS (man-portable air defense systems), have proliferated throughout the world. They can be purchased on the military arms black market for as little as $5,000. More than two dozen terrorist groups, including Al Qaeda, are believed to possess such weapons. The FBI estimates that there have been 29 MANPADS attacks against civilian aircraft resulting in 550 deaths. At least 25 of the reported attacks have been attributed to non state actors. Even though a U.S. airliner has not been attacked by a missile, the question well may be when, not if, such an attack will happen....