The history of airport security shows that the security control process has been subject to substantial changes since its introduction in the early seventies of the last century. In the course of time, threat profiles have changed remarkably. Since 2001, suicide bombing has become a real risk to civil aviation. In the last decade, these changes in threat profiles, in combination with efforts to facilitate transportation by air for passengers, led to large investments into the development of new security technology. This article argues that during the development of security technology, human factor issues as well as different operational aspects should be taken into account at an early stage. It is shown how early operational testing of new technology can contribute to the optimization of security equipment and its integration into the system from a human factors perspective. Operational testing complements laboratory testing and is defined as the testing of (new) equipment in operation with a focus on systemic performance outcomes and operational aspects. Using this methodological approach, a millimeter-wave body scanner and two different liquid explosives detection systems were tested in operation with passengers at a large European airport. Results were obtained by analyzing objective data as well as subjective questionnaire data from passengers and Security Officers. These trials revealed that operational testing is a useful way of enhancing shared knowledge and collaboration between stakeholders.