Abstractone of several distinctproblem areas in determining navigation display requirements is the development of display designs that will facilitate efficient transmission of information to an operator. An important part of this process is the selection of testing procedures that will provide valid, sensitive indications of the merits of new designs. This paper discusses the limitations of flight tests, hi‐fi simulation, and other traditional approaches to navigation display evaluation, and describes in detail a new, “discontinuous simulator” which has been developed to permit more sensitive and efficient measurements than have been possible heretofore. To demonstrate an application of the simulator, data are presented from a test comparing pilot performance on two flight director display systems in current air line se