The CAA-MIT microwave instrument landing system

THE PROBLEM of developing an instrument landing system in which the pilot is kept informed as to both his location and orientation by the indications of a single instrument was put to the Massachusetts Institute of Technology several years ago by I. R. Metcalf of the Civil Aeronautics Authority. The solution of this problem includes the application of centimeter waves, the development of a straight-line glide path, and the realization of a novel instrument combination. Intrinsically and because of recent trends in aircraft navigation these features, we believe, represent significant advances in the art. The experimental development described here in general outline was carried on under the sponsorship of the Authority and was built on MIT´s background of research on the broad problem of navigation in fog and on work in the short-wave field per se as a foundation.¹ The apparatus was designed to demonstrate feasibility only. Commercial embodiment of the results is it is felt now within reach of the industry.