Airline Expansion and Innovation (1927 - 1941)

Results: NACA Contributions


Airfoils. NACA engineers developed many new families of airfoils (wing cross sections), which were used to design most American and many foreign aircraft. Research on high-speed airfoils also reshaped the design of aircraft propellers.


Cowlings. The NACA's most important contribution to the modern airliner was the engine cowl. Enveloping the front of an engine, it increased aircraft speed by smoothing the airflow over the cylinders, while allowing for better engine cooling. For producing the first practical full-cowl design (shown here), the NACA received the prestigious Collier Trophy.


Engine placement. NACA research showed that locating engines directly in front of the wing, with the propellers far in front of the leading edge, reduced drag and enhanced lift and engine efficiency. The gains proved so great that aircraft designers could eliminate nose-mounted engines.

NACA Technical Report
National Air and Space Museum Archives

Publications. The NACA spread the results of its own and other research through publications. This information profoundly influenced American aviation technology and inspired many changes to civil and military aircraft, from flush rivets, tighter construction tolerances, and retractable landing gear to overall fuselage and wing designs.