The Airfoil

 

Whooper Swan (Cygnus cygnus). Selfoss, Iceland. April. Photographer: Peter Cavanagh

Whooper Swan (Cygnus cygnus). Selfoss, Iceland. April. Photographer: Peter Cavanagh

The shape of the curved cross-section that splits the air as it flows over a bird’s wing is called an airfoil. This is clearly visible on the image of the swan (above).

It is not a coincidence that early airplanes and birds share the thin curved wing airfoil shapes. Aviation pioneers copied the airfoils of bird wings for use in their aircraft even though aerodynamic theory was not yet able to explain how an airfoil generated lift.

The Wright brothers inherited tables of lift and drag for various airfoils from Otto Lilienthal— who produced many bird-inspired designs (see adjacent Panel). After disappointing flight tests in 1901 the brothers became convinced that Lilienthal’s tables were incorrect. The invented their own instruments to measure airfoil properties and confirmed that the tables were wrong. The Wright’s new results were a critical breakthrough that enabled the first flight.

 

Airfoil shapes from birds, early airplanes, and the latest Boeing jetliner.

Airfoil shapes from birds, early airplanes, and the latest Boeing jetliner.

Airfoil shape changed rapidly in the decades following the Wright brothers as the science of aerodynamics developed.

LEARN MORE ABOUT SWANS

KIDS QUESTION: In the museum exhibit, we asked: How heavy is a typical swan?

The answer is: Swans are SUPER heavy and can weigh almost 30lb (13.6kg). In contrast, a typical Crow weighs just over a pound (540 grams).

Trumpeter Swans are the largest swans in the US and the largest waterfowl. Large swans can weigh almost 30lb (13.6kg). In contrast, a typical adult male American Crow weighs just over a pound (540 grams).