Title: AVIATION IN THE WEST OF ENGLAND SINCE 1910
1AVIATION IN THE WEST OF ENGLAND SINCE 1910
2FLYING
- People dreamed of be able to fly like the birds
from the beginning of time. - Some people did more than just dream. They spent
years and years of research, experiments, trial
and error, learning all about flight. - At last, in 1903, the Wright Brothers made the
first powered, controlled, aeroplane flight. - By 1910 Bristol aeroplanes the first were being
built at Filton. - Today millions of people have had the chance to
fly thanks to those early experiments.
3FORCES
- One of the things that had to be understood
before humans had a chance to fly were the four
forces of flight. These are - LIFT the upward force that comes from air
moving over and under the aeroplanes wings. - WEIGHT the downward force that comes from
gravity. - THRUST the forward force that comes from the
aeroplanes engine or propeller. - DRAG the backward force that comes from the
resistance caused by the air moving against the
aeroplane.
4LIFT UP
THRUST FORWARD
DRAG BACK
DOWNWARD WEIGHT
BRISTOL FREIGHTER 1950s
5CLIMBING
Thrust has to be greater than drag if an
aeroplane is to climb steadily.
BRISTOL BOMBAY 1936
6DIVING
In a steady dive the weight of the aircraft is
partly pulling it forwards. If the dive is steep
enough the aircraft will speed up even if the
engine is switched off and thrust is zero (like
freewheeling downhill on your bike).
BLACKBURN SKUA WITH BRISTOL ENGINES, 1936
7WINGS GIVE LIFT
When an aeroplane is flying, air is passing over
and under its wings. The air pushed over the
top of the wing is moving faster than the air
below so is spread out more thinly. This creates
lower air pressure above the wing than below. The
curve of the wing increases the speed at which
the air flows. The difference in air pressure
above and below the wing keeps the aeroplane in
the air until the pilot wants to land.
8Sucked upwards from above
o
Pushed upwards from below
AIRBUS A350 2000s
9SOME AEROPLANES GET THRUST FROM A PROPELLER
The propeller is usually turned by a piston
engine. The power comes from four separate
actions taking place one after the other inside
each engine cylinder. SUCK the piston is
pulled down, and air and fuel is sucked in
through the inlet valve at the top of the
cylinder. SQUEEZE the inlet valve closes, the
piston is pushed up and the air inside the
cylinder is squeezed (the technical word for this
is compressed). BANG the fuel is set alight
with a spark. This causes an explosion inside the
cylinder (this is called combustion). The
piston is pushed down strongly. This provides the
power to turn a crankshaft. The crankshaft then
turns the aeroplanes propeller. BLOW the
exhaust valve opens at the top of the cylinder
and hot gas from the explosion is pushed out. The
exhaust valve closes, the piston is pushed up and
the sequence begins again.
10PISTON SEQUENCE
SUCK SQUEEZE BANG BLOW
11This is a famous Bristol piston engine built by
the Bristol Aeroplane Company. It has nine
cylinders.
BRISTOL JUPITER 1920s
12PROPELLERS
All piston engines need propellers to generate
thrust. The BANG of the engine turns the
propeller which then pulls or pushes the
aeroplane through the air.
13SOME AEROPLANES GET THRUST FROM A JET
Like the piston engine, the jet engine SUCKS,
SQUEEZES, BANGS and BLOWS. The difference is
that these actions are taking place CONTINUOUSLY
in different parts of the engine. If the engine
can continuously produce energy it can be more
powerful and efficient. SUCK air is sucked
into the engine by the rotating blades at the
front of the engine. SQUEEZE the air is driven
through the engine by the compressor blades which
squeeze the air into a tighter and tighter
space. BANG fuel is sprayed into the
compressed air so it bursts into flames. BLOW
the hot gases of the flames produce energy to
turn the turbine blades. The turbine produces the
power to drive the compressor. The gases blow out
the back of the engine, thrusting the aeroplane
forward.
14SUCK SQUEEZE BANG BLOW
A JET ENGINE
15The Olympus used in Concorde was a type of
engine known as a TURBOJET. In a turbojet, the
thrust only comes from the jet of hot gases blown
out the exhaust.
CONCORDES OLYMPUS ENGINE, 1970s
16This cutaway picture is of the RB.211. The engine
is assembled at Rolls-Royce in Derby but some of
the parts needed for it are made at Rolls-Royce
at Filton. This is a type of engine known as a
TURBOFAN. In a turbofan, the thrust comes from
the jet of hot gas blown out the exhaust and also
from the cold air that the huge fan at the front
pushes around the sides of the core engine. An
extra turbine is needed to drive the fan. All
modern airliners are powered by turbofans which
can be quieter and cheaper to run than turbojets.
TURBOFAN, 1980s
17CONTROLS
Imagine three lines running through the
aeroplane. Another word for line is axis. The
LONGITUDINAL axis runs from the nose to the
tail. The VERTICAL axis runs from top to
bottom. The LATERAL axis runs from one side to
the other. The lines cross at the aeroplanes
centre of gravity. When the aeroplane is flying
forward, it can rotate around the centre of
gravity on each axis. On most aeroplanes, the
pilot can control the movement using three
moveable flaps the AILERONS, the RUDDER and the
ELEVATORS. When these move, they change the
flow of the air around the aeroplane. By changing
the flow of air, the direction in which the
aeroplane flies is also changed. Controlled
movement is SAFE, STABLE and PREDICTABLE. Thats
just what you want, when you are flying an
aeroplane!
18LATERAL
LONGITUDINAL
VERTICAL
BRISTOL BLENHEIM 1940s
19AILERON
BRISTOL M1D MONOPLANE 1920s
20RUDDER
BRISTOL BABE 1919
21ELEVATOR
BRISTOL BULLDOG 1920s
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