# 3.3.1: Geometry and nomenclature

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Figure 3.20: Wing geometry

In order to characterize the geometry and nomenclature of a typical commercial aircraft wing, the following wing elements are illustrated in Figure 3.20:

• Wingspan $$b$$.
• Chords: root chord $$c_r$$ and tip chord $$c_t$$.
• Leading and trailing edges, and the line corresponding to the locus of $$c/4$$ points.
• $$c/4$$ swept $$\wedge_{c/4}$$.

The area enclosed into the leading and trailing edge and the marginal borders (the section with $$c_r$$) view in a plant-form is referred to as wet wing surface $$S_w$$. The quotient between the wet wing surface and the wingspan is referred to as the geometric mean chord $$\bar{c}$$. which represents the mean chord that a rectangular wing with the same $$b$$ and $$S_w$$ would have.

The enlargement, $$A$$, is defined as:

$A = \dfrac{b}{\bar{c}} = \dfrac{b^2}{S_w}.$

There is also a parameter measuring the narrowing of the wing: $$\lambda = c_t / c_r$$.

This page titled 3.3.1: Geometry and nomenclature is shared under a CC BY-SA 3.0 license and was authored, remixed, and/or curated by Manuel Soler Arnedo via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.