ABSTRACT
A. The Threat Environment The primary threat of concern to aviation over the past two decades has been weapons in the hands of hijackers. Currently x-ray machines are used for searching hand luggage and metal detectors are used for searching passengers. These devices are widely used at airports throughout the world and they have been impressively effective at detecting such weapons and deterring potential hijackers. The searches are nonintrusive and present only a slight inconvenience and occasional delay which the travelling public has been willing to accept. However, more sophisticated devices such as plastic explosives are not readily detectable by either the metal detectors or the standard x-ray devices. Explosives devices fabricated from these materials can be carried by a suicidal terrorist, an unwitting passenger, or checked with luggage by equipping the explosives with a detonation system that has a time delay or is altimeter controlled.
