Page 91 - Aeronautical Engineer Data Book

70 Aeronautical Engineer’s Data Book
4.2 Basic aircraft terminology

Table 4.2 Basic aircraft terminology (see also Figure 4.2)
Aspect ratio (A) A measurement of the
‘narrowness’ of the wing form.
Camber line A line joining the locus of points
situated midway between the
upper and lower surfaces of a
wing.
Dihedral (2 ) Upward or downward (anhedral)
angle of the wing.
Leading edge (LE) Front edge of the wing.
Mean aerodynamic A chord parameter defined as:
+s
chord (MAC) (c) A c dy
2
–s
c =
+s cdy
A
–s
Root chord (c O ) Chord length of the wing where
it meets the fuselage.
Standard mean A chord parameter given defined
chord (SMC) or as

Geometric mean c = S G /b or S N /b
chord (c)

+s cdy
–s

= +s dy
–s
Sweepback ( or ) Lateral orientation of a wing
measured between the lateral
(y) axis and the wing leading
edge LE or LE ), or the 1/4
chord position ( 1/4 or 1/4 ), or
the wing trailing edge ( TE or
TE ).
Tip chord (c t ) Chord length of the wing at its
tip.
Trailing edge (TE) Rear edge of the wing.
Wing (gross) area (S G ) The plan area of the wing,
inclusive of the continuation
within the fuselage.
Wing (net) area (S N ) The plan area of the wing
excluding any continuation
within the fuselage.
Wing plan form The shape of the plan view of the
wing.
Wingspan (b) Distance between the extreme
tips of the wings.