With the introduction of larger and faster types of air transport it seems certain that the importance of all-weather take-off and landing for their safe and economic operation will increase during the coming decade. This paper suggests that a vital factor in this development will be the availability to the pilot of up-to-the-minute information on low level visibility and wind conditions applicable to the runway he is to use. The difficulties of obtaining and forecasting these microclimatic factors are discussed.

We now stand at the beginning of a new decade and one which promises to be as progressive and stimulating for civil air transport as any of its predecessors. Great advances were made during the 60's in establishing and steadily improving the performance of sub-sonic jets. Of equal importance was the enormous amount of preparatory work for the introduction of jumbo jets, air buses and supersonic transports during the 70's, and none was more important than the early stages in developing an all-weather landing system. It may be hoped that by the end of this decade a fully operational all-weather landing system will be available for use at all major airports in the world and there is no doubt that progress towards this goal will be vital to the success of the S.S.T.