40 YEARS OP AERONAUTICAL RESEARCH — ^HTJNSAKER 269 



very high speeds are reached at low altitude, where the air is dense, 

 makes the aerodynamic data readily usable for plane and missile de- 

 sign. In 1945, the NACA established a Pilotless Aircraft Research 

 Station at Wallops Island off the Virginia coast, to carry on this work. 

 It is attached to the Langley Laboratory. 



In 1943, the idea was advanced of using specially designed piloted 

 airplanes to explore the transonic speed range. Propelled by powerful 

 rocket engines and provided with elaborate data-recording equipment, 

 the research airplane could be safely flown at high altitudes where the 

 density of the air, and hence the loads imposed on the structure, would 

 be low. 



The spectacular accomplishments of the research airplanes — the 

 supersonic flight of the Bell X-1, October 14, 1947; the twice-the- 

 speed-of -sound flight of the Douglas D-558-II, November 20, 1953, and 

 the even faster flights of the Bell X-l-A which followed soon after — 

 have sometimes obscured the fact that these airplanes were tools for 

 research. These flights are historic ; all agreed as to the rightness of 

 the Collier Trophy award to three men for the year 1947 : John Stack, 

 Langley Laboratory, for conception of the research airplane program ; 

 Lawrence D. Bell, for design and construction of the X-1, and Capt. 

 Charles E. Yeager, USAF, for making the first supersonic flight. 



But even more valuable than the dispelling of the myth about the 

 sound barrier was the accumulation of information about the tran- 

 sonic speed region. The shape and the performance of tactical military 

 aircraft which have been designed since reflect the use of data obtained 

 by the research airplane program centered at the NACA's High-Speed 

 Flight Station at Edwards Air Force Base, Calif. 



Despite the success of this flight program, there remained the need 

 for a technique whereby transonic experimentation could be carried on 

 under the closely controlled conditions possible only in the laboratory. 

 Actually, the data coming from the research airplanes accented this 

 need, because they pointed up the fundamental problems of fluid me- 

 chanics that would have to be studied in great detail for the design of 

 useful supersonic aircraft. 



By late 1950, following intensive theoretical work, there was put 

 into operation at the Langley Laboratory a new type of wind tunnel. 

 Incorporating a "slotted throat" at the test section, it was free from 

 choking near the speed of sound and truly could be described as a tran- 

 sonic wind tunnel. Again, the Collier Trophy was awarded to John 

 Stack and his Langley associates for the conception, design, and con- 

 struction of his most useful research tool. 



One must appreciate the very great difference between airplane de- 

 sign in the past and today. In the past, the difference between the best 

 design and the second best, assuming the same power, might bo at most 



