Aspect Ratio
The aspect ratio is the relationship between wing span and mean chord. A low aspect ratio (4–5) means stable and forgiving, a high aspect ratio (6+) means high performance but more active flying.
Also known as: AR · wing aspect ratio · Streckung
How the aspect ratio is calculated
For a paraglider, the aspect ratio is formed from two values found in the datasheet:
- span — the spread-out wing in metres
- area — square metres of wing cloth
Formula: AR = span² / area
For a typical school wing that is e.g. 11 m span ÷ 26 m² area ≈ aspect ratio 4.65. A competition two-liner reaches values above 7.
What a high aspect ratio changes
With increasing aspect ratio, the wing becomes:
- faster (higher trim and top speed)
- better gliding (more distance per metre of height)
- more dynamic in its response to control inputs
- more prone to collapses, because the narrower wing tips carry less internal pressure
- harder to control in turbulence
Hence the rule: aspect ratio follows the EN class — EN-A mostly 4.5–5.0, mid EN-B 5.3–5.7, EN-C 6+, EN-D 6.5–7+.
Flat vs projected aspect ratio
Most datasheets show two values:
- aspect ratio (flat) — the geometric aspect ratio of the wing laid out flat
- aspect ratio (projected) — the effective aspect ratio in flight, because a wing has an arc in flight
The projected value is always lower (about 70–75 % of the flat value). Aerodynamically, the projected one counts — it determines how the wing really flies.
Where you will encounter it
When stepping up to the next class. Moving from an EN-A with aspect ratio 4.6 to a high EN-B at 5.7, you feel the jump clearly: faster, more agile, but also more nervous. Experienced pilots like that; beginners need time to adapt.
What does it say about safety?
Aspect ratio alone is not a safety indicator — the EN class is. But: two wings of the same class with different aspect ratios behave noticeably differently in flight. A higher aspect ratio within the same class usually means more dynamic and more demanding.