Background information about aspect ratio:

Flight Notes

Back to the main flight page

Back to page one

What is aspect ratio? Aspect ratio is the ratio between the span (length) of an airfoil and its chord (distance from front to back). It is determined by dividing the span by the chord. For example, if a wing is 12 feet long and 2 feet wide, it has an aspect ratio of 6. Likewise, if a wing is 8 feet long and 2 feet wide, it has an aspect ratio of 4.

In general, wings with larger aspect ratios generate lift with less drag and thus have greater flight efficiency. For example, an aspect ratio of 6 would be more efficient than an aspect ratio of 4.

 

Why is a high aspect ratio wing more efficient? Lift is created by a difference in pressure between the upper and lower surfaces of a wing. In all wings, some of the high pressure under the wing leaks around the wing tip creating a vortex and therefore, drag.

 

 

 

A high aspect ratio wing is efficient because it reduces the formation of the vortex and associated drag.

 

 

 

 

In contrast, a low aspect ratio wing allows the high pressure on the bottom of the wing to escape more easily, resulting in a larger vortex and greater drag.

 

 

Flight Notes

Back to the main flight page

Back to page one