Planes Copying Birds

Aircraft designers have borrowed many of the features that evolved during 150 million years of bird flight. This is known as bio-inspiration. An early example of bio-inspiration was the airfoil shape (see here). By 1920, aircraft also started to stow their landing gear to reduce drag just like birds. In 1980, upturned wing tips appeared as winglets on jet airplanes mimicking the wings of many birds (see here).

Grey Heron  (Ardea cinerea)  Akune, Kyushu, Japan. January. Photographer:  Peter R. Cavanagh

Grey Heron (Ardea cinerea) Akune, Kyushu, Japan. January. Photographer: Peter R. Cavanagh

The Grey Heron (above) shows another feature that has been used in planes. The small cluster of feathers in the middle of the wing (see arrows below) is called the “alula”. It is attached to the bird’s thumb and is deployed at slow speeds to alter the flow of air over the wing and prevent a stall.

Sketch of the Grey Heron (above) with arrows pointing to the alula feathers that are deployed.

Sketch of the Grey Heron (above) with arrows pointing to the alula feathers that are deployed.

Some airplanes have slotted wings with a retractable “slat” on the leading edge that serves the same purpose (see below).

Turbulent airflow over the wing (A) can be attenuated by deployment of a retractable slat (B) similar to a bird’s alula feathers.

Turbulent airflow over the wing (A) can be attenuated by deployment of a retractable slat (B) similar to a bird’s alula feathers.

 

 

 

 

LEARN MORE ABOUT BIRDS AND AIRPLANES

KIDS QUESTION: In the museum exhibit, we asked: What is a big difference between the shape of a bird’s tail and the tail of an aircraft?

The answer is: The airplane tail has a vertical part which is not present in a bird’s tail.
In a typical aircraft, the vertical components are the vertical stabilizer and a rudder.