High-powered piston engines developed for the war effort needed to be produced in ways to solve complex combustion, heat exchange, and supercharger problems. The NACA Aircraft Engine Research Laboratory in Cleveland developed a centrifugal supercharger to provide a single standard test procedure for the engines, which led to significant increases in efficiency.

Of course, any record of NACA’s engine work must acknowledge that the committee concluded early in the war that while jet engine technology had promise, pursuing it aggressively in the near term when the technology was not yet mature would not be the best use of the organization’s resources. Other reasons cited for the less aggressive American approach to jet engine power were the interest of current engine manufacturers in pursuing incremental improvements to existing engines, the large expense associated with jet engine development, a lack of early recognition of the potential of the turbojet (compressor turbine combination) concept and of the overall potential of jet propulsion by NACA – where engine research had less priority than aerodynamic research – and the military services. NACA Langley engineer Eastman Jacobs was the loudest advocate for more attention to jet propulsion at the time, especially for work on the aerodynamics of jet engines, but his pleas went unheeded, and the NACA was not let in on the classified results of British jet research. “I always thought it a shame that Jacobs and his pals weren’t given the proper leadership and ability to move on with that work,” said Chambers. “They [NACA] kind of shot themselves in the foot at the beginning of the war.”

The requirements of World War II fundamentally changed the NACA.

For other problems, NACA often came to the rescue. To improve an aircraft’s stability after a wind gust, the NACA introduced to industry a new set of quantitative measures to characterize the stability, control, and handling qualities of an airplane. To reduce dangerous, out-of-control aircraft spins, the NACA tested more than 300 models of fighters, light bombers, attack and trainer aircraft and contributed to changes in airplane tail designs, which helped pilots recover from high-speed dives. And extensive testing of the supersonic flow of air over various portions of an aircraft flying at subsonic speeds, which had led to steep, uncontrollable dives, led to the development of dive flaps on a wing’s lower surface, which enabled pilots to overcome the effects of “compressibility” and retain control over a diving airplane. These flaps were incorporated into the production of later variants of Lockheed P-38 Lightning fighters, which had been particularly prone to compressibility in high-speed dives, and many aircraft were modified in the field with kits sent from the United States. The P-38 went on to shoot down more Japanese aircraft than any other American fighter.

Another big problem the military leaned on the NACA to solve was the problem of crews being forced to ditch their aircraft into the ocean, especially in the Pacific, usually with disastrous consequences. “We got into this because initially, in 1943, the services needed help because of the ditching problems they were having,” said Chambers. “As a result, virtually every aircraft was put through the tow tank testing at Langley, from fighters to bombers … very detailed tests of how to go about ditching those airplanes, the attitude, the landing gear up and down. People had a lot of different ideas about how to put an airplane in the water. Such things as, ‘Well, what you need to do is enter the water by having one of the tips hit first to make the airplane spin around.’ That turned out to have been one of the most violent approaches that could have been selected based on these tests. Throughout the war, being able to document and specify the optimum way to ditch these airplanes was an important output. After the war, this carried on into commercial aircraft in the test of the 707 that was put into a data base, and although Sully [Capt. Chesley B. “Sully” Sullenberger, pilot of U.S. Airways Flight 1549, the flight that ditched successfully in the Hudson River in 2009] probably never picked up an NACA report, it was certainly the foundation of how the ditching approaches were going to be used.”

By 1944, the professional world took note of NACA’s essential role. In a January editorial, the journal Aviation stated, “How much is it worth to this country to make sure we won’t find the Luftwaffe our superiors when we start that ‘Second Front’? We spend in one night over Berlin more than $20 million. The NACA requires – now – $17,546,700 for this year’s work. These raids are prime factors in winning the War. How can we do more towards Victory than by spending the price of one air raid in research which will keep our Air Forces in the position which the NACA has made possible?”

Such is the legacy of a group that Launius said before the war “was a hobby shop.” The requirements of World War II fundamentally changed the NACA. They forced it to become bigger, to tackle new research challenges, and to address applied as well as basic research. The demands of the war also prepared NACA to assume a larger role in our national life when it would take on more complex aeronautical issues and the initial stages of the looming age of rocketry and spaceflight.

1. Throughout the war the NACA battled with the Selective Service System to keep the military from inducting its best personnel. A late war compromise allowed NACA engineers to be drafted and perform their service duties at NACA facilities.

2 . Prior to the fall of France in 1940, Ide escaped to London and spent the remainder of the war conducting intelligence work for the allies.

3 . NACA reporting at the time showed aerodynamics research papers outnumbered propulsion research papers by a 4:1 ratio.

4 . Roland, Alex, Model Research: The National Advisory Committee for Aeronautics 1915-1958, Volume 1, Washington, D.C., NASA, Science and Technical Information Branch, 1985, p. 167

5 . Chambers, Joseph R., Cave of the Winds: The Remarkable History of the Langley Full-Scale Wind Tunnel, 2014, NASA.

 

This article was first published in the NACA/NASA: Celebrating a Century of Innovation, Exploration, and Discovery in Flight and Space, 1915-2015.