Definition
A United States federal agency, established in 1915 and dissolved in 1958, that conducted aeronautical research and developed standards still used in aviation today, including the NACA airfoil series and the NACA cowling. Its functions and personnel were absorbed into NASA when NASA was created in 1958.
Plain English
NACA was the U.S. government's aviation research agency from 1915 until 1958, when it became part of NASA. A lot of the wing shapes and engine cowling designs still found on aircraft today came out of NACA's work.
Context Anchor
Seen in aircraft maintenance and design references, especially when a manual mentions a NACA cowling, NACA duct, NACA inlet, or NACA airfoil shape.
Derivation
The name is descriptive: it was a 'committee' that 'advised' the U.S. government on 'aeronautics' (the science of flight). Knowing it was advisory, not operational, helps explain why it was eventually folded into NASA, which took on a broader operational and space role.
Why Pilots Care
NACA research created standard wing designs that improve lift and reduce drag on many general aviation and training aircraft.
Intuition Check
Do not treat NACA as the same thing as NASA. NACA was the earlier aviation research agency; NASA came later and has a broader space and aeronautics role.
Example Sentence 1
The wing on this trainer uses a NACA 2412 airfoil, a design developed in the 1930s that is still widely used today.
Example Sentence 2
The NACA 23012 wing section provides good stall characteristics for light aircraft.