206 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1954 



the development of retractible flexible skis for water landing is achiev- 

 ing a practicality that is very evident, as they enable seaplanes to alight 

 on and take off from rough water. This was previously difficult to ac- 

 complish with rigid alighting gear. Demonstrations of the success 

 of this concept have been given in a most convincing manner by 

 the first public flights of Earl Osborn's Edo ski amphibian, the 

 Convair Sea Dart XF2Y-1, and the AU-American ski-equipped land 

 planes. 



Lest we get too set in our ways of thinking that airplane usage means 

 land-field usage, let us look back into history for a moment and realize 

 that there were two or three eras in which the speed records of the 

 world could only be won by airplanes that were launched off the water. 

 This was importantly emphasized in the Schneider Cup ^ races, the 

 international events that were held in the late 1920's and early 1930's, 

 in which the speed of land planes was far outclassed by seaplanes 

 because of their ability to take off from and land on the water surface 

 under conditions of loading and distance that no land area would 

 permit of. Very much the same thing exists today. If our wing sec- 

 tions and high-lift devices were still to limit us to a speed range of 

 somewhere around 6 or 7 to 1 between flying speed and landing speed, 

 and if we wished to build the very fastest airplane to win a race from 

 a surface takeoff (not air launching) , we should have to design a plane 

 that would land and take off at 300 miles an hour and would achieve 

 1,800 to 2,000 miles an hour in the air. This admittedly would be a 

 difficult achievement on a land-field, noncatapult takeoff; but, inter- 

 estingly enough, it would not be difficult for a water-ski seaplane take- 

 off and landing. The only reason that this concept is not as sure-fire 

 as it would have been 25 years ago is that a plane achieving any such 

 high velocity would probably have a thrust greater than the weight 

 and therefore could take off vertically. But it would still have to 

 land; and the vertical takeoff would be considerably easier on the 

 water and much less dusty for the observers. We can only sum up 

 this aspect of our 50 years of progress by pointing out that there is 

 still much thinking, devising, and developing to be done on the funda- 

 mental problem of how we take off from the earth and how^ we get 

 back to it. 



WING STRUCTURES 



The configuration of the wing structures of aircraft, from the origi- 

 nal Pratt-truss Wright biplane, has gone through quite a cycle of de- 

 velopment, befogged by an enormous amount of prejudice, misunder- 

 standing, stubbornness, and lack of sound engineering foresight. In- 



' This trophy was established in 1913 by Jacques Schneider, of France, as an 

 incentive for high-speed seaplane development. 



