The Ancient Chinese :
Kites with curved surfaces flew better than kites
with flat surfaces.
Leonardo da Vinci, 1486-1490:
The idea of strapping a pair of wings to arms fail out of
favor & replaced by the concept of wing flapped up & down.
Lilienthal and Cayley:
In the 1800s, demonstrated that a curved surface
produces more lift than a flat surface
Wilbur and Orville Wright:
Construction of fixed wing aircraft and use of
ailerons. Material used is Spurce. Discovery of
What is Wing?
“A wing is a type of fin with a surface that
force for flight or propulsion through
the atmosphere, or through another
gaseous or liquid fluid. As such, wings have
an airfoil shape, a streamlined cross-sectional shape
How Lift is Generated ?
The basic principle behind an lift is described by
“Air that travels over the top surface of the airfoil has
to travel faster and thus gains dynamic pressure. The
subsequent loss of static pressure creates a pressure
difference between the upper and lower surfaces that is
called lift and opposes the weight of an aircraft (or
thrust that opposes drag)”.
As the angle of attack (the angle between the chord line
and relative air flow) is increased, more lift is created.
Once the critical angle of attack is reached (generally
around 14 degrees) the airfoil will stall.
Wing construction is similar in most modern
aircraft. In its simplest form, the wing is a
framework made up of spars and ribs and
covered with metal. The construction of an
aircraft wing is shown in figure.
Internal Structure of
Ribs: The parts of a wing which support the covering and
provide the airfoil shape.
Spar: Running span wise at right angles (or thereabouts
depending on wing sweep) to the fuselage.
Stringers: A strip of wood or metal to which the skin of an
aircraft is fastened
Internal Structure of Wing(Contd.)
Skin: The outer surface of the wing. Originally made of
fabric, modern aircraft use aluminum or composite materials
due to their lightweight and rust-resistant properties.
Fuel Tank: Commonly located in the wing, fuel can either be
housed in its own tank or allowed to fill the cavities between
Flaps: Are a “high lift / high drag” device. Not only do they
improve the lifting ability of the wing at slower speeds by
changing the camber, or curvature of the wing, they also
create more drag, meaning an aircraft can descend, or lose
altitude faster, without gaining airspeed in the process.
Internal Structure of Wing(Contd.)
Root: The wing root is the portion of the wing that
attaches to the fuselage, or body of the aircraft.
Wing Tip: The wing tip is furthest from the fuselage and
is typically where the navigation lights are mounted (a
red light on the left, a green light on the right).
Slats: Another “high lift” device typically found on swept
or delta wing aircraft. Slats are similar to the flaps
except they are mounted on the leading edge of the
wing. They also assist in changing the camber to improve
lifting ability at slower speeds.
Aspect Ratio: The ratio of the wing’s length to its chord
Camber: The name given to the curvature of the upper or
lower surfaces of the wing.
Chord Line: The theoretical line running from the leading
edge of the wing to the trailing edge.
Leading Edge: The front edge of an aircraft’s wing.
Trailing Edge: The rear edge of an aircraft’s wing.
Wing Construction & Mathematics
Ailerons increase or decrease lift asymmetrically, in order
to change roll and, thus, move the aircraft left or right
while flying. Ailerons are hinged sections fitted at the rear
of each wing
Stability Devices on Wings
Stability Devices on Wings(Contd.)
Flaps are devices used to alter the lift characteristics
of a wing and are mounted on the trailing edges of
the wings of a fixed-wing aircraft to reduce the speed
at which the aircraft can be safely flown and to
increase the angle of descent for landing. They shorten
take off and landing distances. Flaps do this by
lowering the stall speed and increasing the drag.
Leading Edge = Forward edge of the aerofoil
Trailing Edge = Aft edge of the aerofoil
Chord = Line connecting the leading and
trailing edge. Denotes the length of the
Mean Camber Line = Line drawn half way
between the upper and lower surface of the
aerofoil. Denotes the amount of curvature of
Point of Maximum Thickness
= Thickest part of the wing
expressed as a percentage of the chord
Airfoil: It is the shape of a wing or blade (of a propeller,
rotor, or turbine) or sail as seen in cross-section.
Drawbacks of Conventional Wings:
A. Higher control power required.
B. Incurring extra drag and fuel consumption increases.
C. At high angles of attack stall problems occurred.
D. Flap deployment causes nose down pitching
moments which must be overcome by elevator
and/or horizontal tail deflection causing the overall
maximum lift to go down.
Features of some unconventional
The canard (forward lifting surface)
Weight savings since the
horizontal tail is eliminated.
Savings in drag which will
result in better speed and
range characteristics (lower