Definition
The ratio of a wing's span (tip to tip) to its average chord (leading edge to trailing edge). It is calculated as wing span squared divided by wing area. A long, narrow wing has a high aspect ratio; a short, stubby wing has a low aspect ratio.
Plain English
A number that describes how long and narrow a wing is compared to how wide it is front-to-back. Long thin wings have a high number; short fat wings have a low number.
Context Anchor
Seen in discussions of wing design, low-speed flight, slow flight performance, and how different airplanes handle at high lift settings.
Derivation
From Latin aspectus, meaning 'a look' or 'appearance,' combined with 'ratio.' The term literally describes the visual proportion of the wing — how it looks when viewed from above.
Why Pilots Care
Affects induced drag, lift efficiency, stall characteristics, and glide performance.
Analogy
A long, narrow table and a short, wide table can have similar surface area, but they have very different shapes. Aspect ratio is the wing’s version of that shape comparison.
Intuition Check
Do not read “aspect” as just the airplane’s appearance or viewing angle. Here, aspect ratio is a specific measurement of wing length compared with wing front-to-back width.
Example Sentence 1
Gliders are designed with a very high aspect ratio so they can stay airborne with minimal drag.
Example Sentence 2
A low aspect ratio wing on the trainer gave quicker roll response but required more power in turns.