Book excerpt: The Federal Aviation Agency, through contract with the Applied Psychology Corporation, is conducting research intended to lead to a determination of requirements for lighting systems, paint treatments, and other conspicuity aids which will be of maximum assistance to pilots in avoiding mid-air collisions during VFR flight. Important among the relevant considerations are such human factors problems as the delineation of the optimum amount of information pilots need for evaluating collision threats and the specification of the most efficient operating procedures. This booklet describes four test facilities which make up a portion of this contract effort. The findings of the research will have application for 75% or more of all flights currently being flown in the United States.