582 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1941 



Next are shown views of flying equipment which may be important 

 in further development. First, in plate 9, figure 1, there is the Mayo 

 composite airplane arrangement which by means of assisted take-off 

 provides the operating, or top unit, with increased speed and range 

 which may therefore be a factor in trans- Atlantic mail flying. 



In plate 9, figure 2, there is shown a view of a model of a helicopter, 

 a type of aircraft which will be used for transporting mail and pas- 

 sengers from airports to roof tops in the centers of cities and even, in 

 many cases, for short-haul traffic directly between city centers. In 

 addition it may revolutionize our conception of private-owner air- 

 craft. 



Plate 10, figure 1, is a view of the Curtiss- Wright Model Twenty 

 with pressurized cabin and with extremely large baggage and express 

 compartments. A noteworthy contribution to economy of operation 

 is expected when this plane goes into service, making it eminently 

 suitable for use between large centers of population. Other views 

 of this plane during its development are shown in plate 11, figure 1, 

 which is an interior view of one arrangement which accommodates 30 

 passengers, and plate 10, figure 2, which illustrates, in a construction 

 view, the unique manner in which structural provision for pressuriza- 

 tion is provided, accompanied by provision for tremendous bulk of 

 baggage, express, and freight under the cabin floor. An idea of the 

 size of the plane is shown in plate 11, figure 2, where one of its four gas 

 tanks is set beside a two-place training plane ; the tank is almost as 

 large as the entire fuselage of the training craft. Plate 12 is a view 

 of the plane in flight over New York City. This plane will provide 

 still higher standards of safety and economy in operations. 



The final illustrations of this paper are views of the most modern 

 equipment now flying; the beautiful Boeing Pan American Clipper 

 (pi. 13, fig. 1) and the Douglas DC-4 (pi. 13, fig. 2). Last of all, 

 two views illustrating a prediction of Mr. Sikorsky of the trans- 

 Atlantic airliner of the future, plate 14, figure 1, showing the dining 

 salon and plate 14, figure 2, the flying boat itself in the air. 



CONdiUSION 



We have thus reviewed transport aviation, showing its history from 

 "infancy" to 1911, through "romantic childhood" to 1926; "painful 

 adolescence" to 1931 ; its satisfactorily progressing "young manhood" 

 to the present time ; and its promise of "maturity" for the future. One 

 cannot but be inspired by contemplating some of the following : 

 A recent TWA timetable schedule headed "Europe — New York — Chi- 

 cago — Los Angeles — San Francisco— Asia." 

 The growth of one of the United States air systems, American Airlines, 

 Inc., from its first passenger in April 1927, to its millionth in Feb- 

 ruary 1937, and its two millionth in September 1939. 



