MODERN TRENDS IN AIR TRANSPORT 



By W. F. DuKAND 

 Leland Stanford University 



In a domain as varied and as active as is air transport at the pres- 

 ent time, I can only hope, in the time which I must occupy this after- 

 noon, to touch on some of the more important phases of the subject. 

 And first, by way of introduction, I should like to rehearse with you 

 a few simple and elementary points regarding the airplane — a body 

 heavier than the air, yet which, for service in air transport, must 

 depend on sustained movement through the air. 



Let us then picture the airplane as a complex of four systems as 

 follows : 



1. The lifting system. 



2. The nonlifting system. 



3. The propulsive system. 



4. The control system. 



The lifting system is, of course, represented by the wings. The 

 nonlifting system is represented by the body or fuselage, the purpose 

 of which is to provide a central structural member, with space for 

 personnel and pay load, to provide suitable support and location for 

 the rudder and elevator as parts of the control system, and often to 

 house, at the nose, an engine and propeller shaft. The propulsive 

 system comprises the engines and propellers with function as indi- 

 cated by the name. The control system comprises rudders, elevators, 

 ailerons, flaps, slots, etc., all intended to place in the hands of the 

 pilot control over the movement of the plane in the air and also in 

 taking off from the ground and returning thereto. 



Now, what are the things about an airplane and its performance 

 in which we have a special interest? I shall put them down in this 

 order : 



1. Safety. 



2. Carrying capacity. 



3. Speed. 



4. Range. 



5. Economy. 



6. Comfort. 



1 Address given at the 39th annual convention of Sigma Xi at Richmond, Va., December 

 28, 1938. Reprinted, with author's revisions, by permission from Sigma Xi Quarterly, 

 vol. 27, No. 1, March 1939. 



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