Selection and Pre-employment Assessment of

For years, terrorist attacks have presented a constant threat to civil aviation and highlighted the importance of aviation security. Threats that have reached new dimensions demand a reliable security check, not only for hold baggage but also for passengers and their carry-on baggage. For example, the terror attack on September 11, 2001, has revealed a new dimension. Former terror attacks were comparable to Lockerbie 1988, when Pan Am Flight 103 was destroyed by a bomb in the hold baggage. As a result, immediate changes regarding hold baggage screening were introduced, and automated systems for detecting improvised explosive devices (IEDs) in hold baggage were developed. However, in the recent past, suicide bombings have become more likely, and therefore enhanced security checks of passengers and their carry-on bags have become necessary. Although new state-of-the-art technology, such as automatic liquid detectors, millimeter wave systems, X-ray machines with automatic detection of explosive materials, and so forth, facilitate the detection of threat items, the final decision is still made by human operators (screeners). It has been argued that with advances in technology, the cognitive demands on humans are increased rather than lowered.