Retrospect – The NACA air duct

Designed for aircraft

Rooted in aeronautics but more commonly known for its automotive applications, the NACA (not NASA) duct is a timeless piece of functional design that has gone through decades unchanged, never needing to adapt to prevalent trends. The NACA duct was conceived in 1945 by aeronautical engineers at the National Advisory Committee for Aeronautics, a government body that would later become NASA. The duct was intended to direct air into jet engines without creating additional drag, but the design wasn’t as effective as needed in aeronautical use. However, as NACA declassified the invention in 1951, the duct was soon used in the automotive world. Being submerged into the bodywork, NACA ducts don’t increase drag like lifted scoops do while its design made it great for both air supply and cooling.

Early testing

Naturally, the first experiments with the freshly declassified invention were in racing. Several blurry black and white photos show Le Mans-ready 1951 Talbot Lago T26 GS 11055 and 1955 Connaught B Type Streamliner being the first cars to use them, but it was Frank Costin’s 1956 Vanwall F1 car that is widely credited as being the first car to adopt a NACA duct. An aeronautical engineer by trade, Frank Costin went on to use the NACA duct on his subsequent projects too, and by the early 1960s the novel air inlet was becoming increasingly present on racing cars of all kinds, slowly catching on in the automotive mainstream too.