Weather
Weather takes many forms, and it varies from day to day. Changes may also
occur rapidly and it is important for all pilots as well as other aviation-related
personnel to be constantly aware of even small changes, which may affect flying
conditions.
2.6 Air Activities – Bays Resource Disc 2011
2.6 Air Activities – Bays Resource Disc 2011
Monoplanes and Biplanes
A monoplane is an aircraft with one main set of wing surfaces. Some examples
of monoplanes are shown below:
The high-wing of a de
Havilland
Canada Dash 8.
The low-wing of a Yak-18
A parasol wing Pietenpol Air
Camper amateur-built aircraft.
A biplane is a fixed-wing aircraft with two main wings. The Wright brothers' used
a biplane design, as did most aircraft in the early years of aviation.
Some examples of biplanes are shown below:
WW1 Sopwith Camel biplane
WW1 Nieuport 17 scout
Rutan Quickie tandem wing
biplane
A tandem wing biplane has one wing in front of the other (e.g. one wing in the
nose and a wing in the tail), like the Rutan Qucikie shown above
Advantages and disadvantages
Aircraft built with two main wings can usually lift up to 20% more than can a
similarly sized monoplane of similar wingspan, which tends to provide greater
maneuverability. The struts and wire bracing of a typical biplane form a box
girder that permits a light but very strong wing structure.
On the other hand there are many disadvantages with biplanes. Each wing
negatively interferes with the aerodynamics of the other. For a given wing area
the biplane produces more drag and less lift than a monoplane. For this reason,
since the late 1930s the monoplane has been the "ordinary" form for a fixed wing
aircraft.
2.6 Air Activities – Bays Resource Disc 2011
Parts of an Aircraft
AILERON
The ailerons are joined by wires, so that when one goes up, the other goes down.
Moving them makes one wing rise and the other drop.
COCKPIT
ELEVATORS
The pilot's compartment of an aircraft, also called the cabin.
ENGINE
FLAPS
A machine that uses heat energy to develop mechanical power.
FUSELAGE
The "body" of the airplane. The body of a Jet Airliner is built from hundreds of metal
struts, circular hoops and lengthwise stringers. These are covered with a "skin" of
lightweight metal such as aluminium. In many jets, the passengers' seats are in the
top part, with the area below used for storage.
LANDING
GEAR
The wheels, floats, skis, and all of the attachments, which support the airplane when
it is resting on the ground or water
PROPELLER
A typical aircraft is guided and steered by three main sets of control surfaces, a
rudder, two elevators on the tailplane, and two ailerons on the wings. Elevators tilt
upward to make the plane ascend; elevators tilt downward to make the plane
descend.
Most large aircraft have extra movable parts called flaps on their wings. Flaps are
used during takeoff to produce extra lift with low drag. When landing the aircraft, flaps
are used to produce extra lift with extra drag.
The first aircraft propellers were made from wood, but as aircraft became faster they
had to be replaced with stronger materials such as steel. A propeller is used to propel
the aircraft forward. As the propeller turns, its blades pull air in from the front and
push it out the back. At the same time, these blades also work like spinning wings,
because they have an airfoil shape. Instead of lifting upward, however, they thrust
the aircraft forward.
RUDDER
The movable vertical control surface used to rotate the airplane about its vertical axis.
Moving the rudder to the right turns the aircraft's nose to the right. Moving it to the left
turns the nose to the left.
TAIL
The combination of the rudder, elevator and fixed horizontal and vertical stabilizing
surfaces.
WING
Most aircraft are heavier than air and can fly only because they have wings. Wings
are curved more above than below, this special shape is called an airfoil. Airfoils are
important because an upward force called lift is created by the way air flows around
them. Winged aircraft can only fly when there is enough lift to overcome their weight.
In addition, they must be moving fast enough to create lift by keeping air flowing past
the wings.
2.6 Air Activities – Bays Resource Disc 2011
Air Speed vs Ground Speed
Ground speed is the speed of the aircraft relative to the ground rather than
through the air, which can itself be moving.
Air speed is the relative velocity between the aircraft and the air. Airspeed.
cannot be directly measured from a ground position, but must be computed from
the ground speed and the wind speed.
Airspeed is the vector difference between the ground speed and the wind speed.
Airspeed = Ground Speed – Wind Speed
2.6 Air Activities – Bays Resource Disc 2011
Theory of Flight
Flight is made possible by a careful balance of four physical forces. These are
shown on the diagram below:
A = Lift
B = Thrust
C = Gravity
D = Drag
For flight, an aircraft's lift must balance its weight, and its thrust must exceed its
drag. A plane uses its wings for lift and its engines for thrust. Drag is reduced by
a plane's smooth shape and its weight is controlled by the materials that it is
constructed of.
Lift: Air flowing over the wings and the angle of the wing relative to the passing
airtogether move the aircraft upward.
Gravity: The opposite of lift, gravity is a force pulling down on the airplane.
Thrust: A force created by the engine that moves the airplane forward.
Drag: The opposite of thrust, drag is a force that slows the forward movement
of the airplane through the air. The surfaces of the plane cause drag as they
move through the air.
2.6 Air Activities – Bays Resource Disc 2011
Airplane Controls
A = Ailerons B = Flaps C = Elevator D = Rudder E = Propeller
Ailerons: Help to turn the plane. They work in opposition to one another. When
the right aileron goes up, the left one goes down and vice versa. They change the
shape of the plane’s airfoil to turn the plane. Ailerons control bank.
Flaps: Help to slow the plane down. Flaps are use most often in landing, when
the pilot slows the plane down to an appropriate speed for landing. Flaps change
the shape of the airfoil, and both go down or up at the same time, in the same
direction.
Elevator: Helps the airplane ascend and descend. When the tail goes up, the
front of the plane goes down, and vice versa. Elevators control pitch.
Rudder: Together with the ailerons, the rudder helps to turn the plane. The
rudder controls the yaw of the plane.
Propeller: Produces thrust, pulling the plane forward.
2.6 Air Activities – Bays Resource Disc 2011