Definition
An early airfoil refers to the wing cross-section shapes used on the first powered aircraft, characterized by a thin, highly curved (cambered) profile with the upper and lower surfaces nearly parallel. These shapes were developed before the systematic aerodynamic research of the 1920s and 1930s and produced relatively low lift, high drag, and poor structural depth compared to later designs.
Plain English
The simple, thin, curved wing shape used on the earliest airplanes, before engineers learned how to design more efficient wings.
Context Anchor
Seen in the Pilot’s Handbook of Aeronautical Knowledge in a figure comparing different airfoil designs.
Derivation
“Airfoil” combines “air” with “foil,” an older word for a thin sheet or leaf-like shape. In aviation, an airfoil is the shaped part that works in moving air, such as a wing. “Early” here means early in aircraft design history, not early in a flight.
Why Pilots Care
Knowing how airfoils evolved helps a pilot understand why modern wings perform better at a wider range of speeds and angles, and why aircraft from different eras handle the way they do.
Grounding Statement
Picture cutting through a wing from front to back; an early airfoil is one of the older versions of that sliced wing shape.
Intuition Check
Do not read “early” as meaning “soon” or “before takeoff.” Here it means an older design from earlier aircraft development.
Example Sentence 1
The Wright Flyer used an early airfoil that was thin and heavily curved, which limited how fast and how far it could fly.
Example Sentence 2
Pilots studying airfoil history learn that early airfoils produced good lift at low speeds but created more drag than modern sections.