CONTROL OF AIR TRAFFIC

Press, Volume LXIX, Issue 21024, 28 November 1933, Page 11

CONTROL OF AIR TRAFFIC

AVOIDING COLLISIONS NEW SYSTEM AT CROYDON (rao.M oue ows cohbespokdent.) LONDON, October 19. The risk of collision when aeroplanes are near a terminal aerodrome in mist or fog, has led to the organisation of a system of "zone control," which will be put into force shortly near Croydon. Experience has shown that the physical characteristics of the country near the airport make impracticable the allotment of separate traffic lanes for incoming and outgoing aircraft; the new system, which has been accepted by the air transport companies using the aerodrome, empowers the traffic control officer to order all aeroplanes to keep out of a zone extending 10 miles round Croydon till permission, =is given them to come in and land. Major R. H. S. Mealing, chief technical assistant in the Directorate of Civil Aviation, who made this announcement in a lecture before the Royal Aeronautical Society, declared that even if success attended efforts being made to devise a means whereby one aircraft could automatically indicate its proximity to other machines, the problem of controlling traffic m bad weather would not be solved. He prophesied the greatly extended use of wireless, in the form of radio beacons, and of light beacons. Short range radio beacons would indicate to a pilot Hying along the rou'" his precise position till he got wiunn range of the main aerodrome beacons. In Major Mealing's opinion air routes would in the future be divided into sections with a control officer in charge of each, much in the same way as a railway signalman controls his own section of the line. Each control officer would have in front of him an indicator showing the exact position in space of each machine in his section. Increasing Speed. The problem of controlling air traffic was complicated because flying machines move in three dimensions.-Major Mealing continued: "This method of confining aircraft to routes must become complicated if one is going to insist on all aircraft of greatly varying speeds following the same route or, if so, at any height near to one another; therefore, by the time we have the mail carrier and fast passenger-carry-ing aircraft flying at 500 miles an hour, and yet are obtaining useful service for carrying cargo from the old air tramp which might continue to fly at 200 to 300 miles an hour, we must consider either that these two classes fly on different routes or that possibly the fast machines will fly very high." Sometimes as many as 20 machines were approaching or leaving Croydon at the same time. The problem would become more and more urgent with the growth of flying. Hence the new "zone control" scheme, which would come into action in future, whenever visibility was reduced to the international fog standard—looo yards vision horizontally and 1000 feet vertically.