This paper, and the papers by Gérardin and Payne which follow, were presented at the meeting of the Deutsche Gesellschaft für Ortung und Navigation held in Dusseldorf 5–7 June 1962 and are printed with that body's kind permission. An account of the meeting was published in the last number of the Journal (16, 111).

The scientific engineering review of the U.S. Task Force on air traffic control, known as Project Beacon, was completed in the fall of 1961. In their report to the Administrator of the Federal Aviation Agency, the Task Force makes no claim for originality of most of the ideas and recommendations which were presented. Consequently, many of the problems resulting from the proposed plan of action have been previously discussed. However, the very positive and specific treatment of basic principles and the presentation of clear decisions produced considerable impact. The blurred picture created by less definitive approaches has been brought into better focus. The remaining problems are reduced in number, implementation efforts can be concentrated and the probability of success has been increased.