NACA and Documenting of Progress in Aerodynamics

NACA LogoThe aeronautical research that the NACA between 1915 and 1958 undertook found dissemination in a complex set of technical publications that the agency made available to all on an equal basis. Most NACA research was accomplished “in-house” by scientists or engineers on the federal payroll. Work conducted under research authorizations might be of short-duration or could be years in the accomplishment. Short-duration work was often aimed at resolving a specific technical problem, many being tied to the development of a military aircraft prototype. One example of this approach was the effort to improve the aerodynamic efficiency of aircraft, an especially important activity in World War II as the NACA performed worked on drag cleanup for 23 different military aircraft.

Especially when the research was of long duration the NACA issued “Technical Notes” partway through containing interim results and “Technical Reports” with major research conclusions at the end of the effort. No one and no political issue, old NACA hands recollected, infringed upon the presentation of their findings in the most evenhanded manner possible. Thus they believed that partly for this reason the organization became the premier aeronautical research institution in the world during the 1920s and 1930s.

Many of the longer research projects took years to complete and were redefined and given additional monies repeatedly to pursue technological questions. A good example of a longer-term effort was Research Authorization 201, “Investigation of Various Methods of Improving Wing Characteristics by Control of the Boundary Layer,” signed on January 21, 1927. It provided for broad-based research at NACA on methods for either blowing or sucking the boundary layer along the upper surface of the wings, thus maintaining laminar flow and preventing airflow separation. Research took place between 1927 and 1944, taking a variety of twists and turns. Those efforts were channeled at first toward immediate practical objectives that could be used by industry and other clients. Later the NACA staff pursued other avenues of exploration, and the result was that the NACA was able to greatly advance boundary layer control through modification of airfoil shape, demonstrating the serendipitous nature of research. The boundary layer research by NACA engineers is still being used as the foundation for current research efforts.

As research was being conducted the NACA printed its findings, and this proved to be the most significant output from the agency’s activities. Beginning in the 1920s the NACA issued several types of reports describing research findings:

  • Technical Reports (TR): the most prestigious, most polished, most important, and most widely distributed report, TRs described the final results of a research effort and made “lasting contributions to the body of aeronautical knowledge.”
  • Technical Notes (TN): TNs reported on work in progress, offered interim findings, or served as final reports for less significant research activities.
  • Research Memorandum (RM): introduced in 1946, RMs reported on research undertaken as classified work for the military.
  • Advanced Confidential Reports (ACR): also introduced after World War II, ACRs reported on sensitive military aeronautical subjects such as jet engines, low-drag wings, or investigations of specific military aircraft types.
  • Bulletins: were short progress reports on limited phases of larger research projects.
  • Memorandum Reports (MR): reported on pieces of aeronautical research of interest to a very small group of clients, generally on a specific type of aircraft or engine design.
  • Technical Memoranda (TM): reported on aeronautical research conducted somewhere other than at NACA, often these were translations of technical articles published in a foreign language.

During the existence of NACA, it printed more than 16,000 research reports of one type or another. TRs were publicly available, readily accessible to anyone with a need to know the information. They were distributed to a huge mailing list that included laboratories, libraries, factories, and military installations around the world. They became famous for their thoroughness and accuracy, and became the rock upon which NACA built its reputation as one of the best aeronautical research institutions in the world. Other reports were less widely distributed, but unless classified for security purposes, were available to anyone with an interest.


Pearl I. Young

The architect of the technical reporting was Pearl I. Young (1895-1968), who came to work at the NACA’s Langley Laboratory in 1922 after graduating with a physics degree from the University of North Dakota. After working in the instrumentation division for a few years she suggested that Langley required someone to oversee the technical reports system, which at that time was in disarray. Young took on that responsibility and led the effort until World War II. She created the multitude of documents issued by the NACA, enforced the NACA style of presentation on authors, ensured technical verisimilitude, and handled document distribution far and wide.

Young preached that knowledge is the end product of a research laboratory, and that accordingly the preparation of the research report must receive special emphasis. He insisted that these documents present their data “tactfully, strategically, and with telling force.” She ensured that all publications were accurate, well organized, and effectively structured. Not to give appropriate attention to the presentation of research would ensure that the report would be neither read nor used. She enforced a harsh clarity on the technical reports process at the NACA, one that quickly paid dividends as the results of the agency’s researchers gained stature around the globe for both their path-breaking results and their effective communication.

Young’s oversight of the technical report program was always exacting, sometimes to the consternation both of NACA engineers who wanted to see their work disseminated promptly and viewed Young’s efforts as bogging down the process, and to industry or military clients who wanted prompt answers to aeronautical problems. She argued that the quality of the final product was more important than the speed with which it appeared; Young had all documents extensively vetted by a panel of engineering peers but as a means of speeding the process she also allowed preliminary reports to circulate to key users. Before a report was final, however, authors made revisions, sometimes extensive revisions, before editorial work was completed on the publication. Young insisted that all reports be “checked and rechecked for consistency, logical analysis, and absolute accuracy.”

Pearl Young went on to other responsibilities during World War II at the NACA’s Cleveland, Ohio, Aircraft Engine Research Center. She eventually moved to Pennsylvania State University to teach engineering physics but returned to NASA in 1958 before retiring in 1961. She commented on many occasions about the noble effort they were engaged in—separating the real from the imagined in flight—adding that “There are just as many aeronautical research problems for you to solve by the application of brains and hard work as there were on the day Orville Wright piloted the first airplane at Kitty Hawk in 1903.”

Orville Wright, Charles Lindbergh, and Howard Hughes were among the attendees at Langley's 1934 Aircraft Manufacturers' Conference. Conference guests assembled underneath a Boeing P-26A Peashooter in the Full-Scale Tunnel for this photo. (NASA Phtoto L-9850)

Orville Wright, Charles Lindbergh, and Howard Hughes were among the attendees at Langley’s 1934 Aircraft Manufacturers’ Conference. Conference guests assembled underneath a Boeing P-26A Peashooter in the Full-Scale Tunnel for this photo. (NASA Phtoto L-9850)

The research reported in these technical publications was never presented quickly enough to satisfy clients, although Young always defended the deliberate process she followed to ensure the best possible product. This, however, was nothing compared to the more difficult challenge of remaining an honest broker on research projects. Industry forever wanted to use the NACA as its private R&D facility. Accordingly, the agency had to establish a policy of not working on a specific type of aircraft design, because it smacked of catering to one particular company. Instead, it agreed to work on problems common to all aspects of flight, such as the engine cowling problem for which it received its first Collier Trophy in 1929. It also published research results and distributed reports on an equal basis to all. The NACA often violated these policies when dealing with its principal client, the military services.

Beginning in the 1930s, because of pressure to cut the federal budget, the NACA also established a table of fees for charging private companies, usually those involved in the aeronautical industry, when it pursued research problems they suggested. In this scenario the requestor paid all costs of research. In return, the NACA agreed to give the requestor the results of the research, but also retained the right to release findings it deemed in the national interest. This approach had two negative effects: (1) it allowed larger aircraft firms with money to spend on these problems an opportunity to squeeze out weaker firms who could not compete with cutting edge technology; and (2) it dissuaded some industry leaders from asking the NACA to work on pressing aeronautical problems because of both lack of money and a fear that their investment in the research would be lost when the findings were distributed to the world.

naca-pulsejet-22-tests-coverDuring the course of the NACA’s history between 1915 and 1958 it did very little “project” work of its own, at least as this term has come to be known at NASA. The NACA’s emphasis was on research for the use of outside entities. The principal means of transferring this research knowledge was through a series of reports which could be used as the clients saw fit. An important secondary means of transferring this information was through the annual conferences sponsored by NACA after 1926.

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