464 BELL SYSTEM TECHNICAL JOURNAL 



information to planes in flight and for transmitting directive radio 

 beacon signals for enabling planes to keep on the course. In conjunc- 

 tion with these services it had contracted for 24-hour teletypewriter 

 service along 13,000 miles of main airways connecting some 250 sta- 

 tions, principally for the purpose of transmitting weather reports and 

 to assist in dispatching the planes. All of these facilities have been 

 made available without cost to aircraft operating companies and others 

 using the airways. 



In addition to this communication service contracted for by the 

 Government, approximately 5,000 miles of teletypewriter circuit are 

 used daily in furnishing private wire communication service to a 

 number of transport companies for transmitting information pertaining 

 to the operation of their own lines. Routes on which these facilities 

 are furnished to the Government and transport companies are indi- 

 cated by heavy lines in Fig. 1 . 



When the first air mail service was established, radio telegraph was 

 introduced as a means of point-to-point communication along the 

 New York-Chicago-San Francisco airway route. At each radio station 

 meteorological data were collected from surrounding points by means of 

 long distance telephone and telegraph and these data were exchanged 

 periodically through the day with the other stations over the radio 

 telegraph. 



With a rapid expansion in air transport service foreseen it was ap- 

 parent there would be a large increase in communication requirements 

 not only to equip new routes but to handle increased volume on existing 

 routes. There was the definite requirement for radio telephone com- 

 munication with planes which would need a number of the radio 

 channels allotted to this service. Considering these factors and the 

 geographic and other conditions applying to probable development of 

 air transportation in the United States, it seemed that regular point-to- 

 point service served by radio telegraph could be provided more satis- 

 factorily in another way. 



Arrangements were made in 1928 for teletypewriter communication 

 services at several points connecting radio stations with their local 

 weather bureau offices in order to expedite the delivery of weather re- 

 ports and other traffic handled by radio telegraph. Shortly afterward, 

 a teletypewriter system was installed on the New York-Cleveland route 

 connecting the Department of Commerce and Weather Bureau stations 

 at Hadley Field, Stelton, N. J., and Cleveland, Ohio, and a number of 

 intermediate points. This type of service seemed ideally fitted for use 

 in weather reporting and plane dispatching and has been extended not 

 only to replace the service furnished by the radio telegraph system but 

 also to provide for communication requirements on other routes. 



