hello everyone and welcome back to the
flectus channel
the need for dependable high-performance
engine designs has become more and more
necessary with the advancement of the
aviation industry both in the military
and civilian air transport sectors
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this need became very obvious as far
back as the 1950s when airplanes began
switching from propeller driven engines
to jet engines
arrow engine manufacturers too have been
in a neck to neck race to meet this
pressing need with pratt and whitney
counting amongst the most successful of
them
headquartered in east hartford
connecticut the company has been
producing engines for both civil and
military crafts since 1925.
reciprocating engines to turbo jet and
even rocket propulsion the company has
grown alongside the aerospace industry
from the very start to this new age of
propulsion systems
what you're seeing with aircraft is
they're becoming more integrated and
there's no better example of that than
the propulsion system
pratt and whitney's engines have been
used on some of the united states air
force's most popular and valuable
aircraft
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among them is the f-35 lightning the
newest generation of u.s fighter
aircraft that rely on specially designed
pratt and whitney engine for propulsion
it uses a custom f-135 low bypass
augmented turbofan engine offering over
40 thousand pounds of thrust
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the main thrust here is improving the
emission weighted fuel burn of this
engine
we put in a package of advanced
aerodynamics in both the compressor and
turbine
shooting for a five percent reduction in
fuel burn and we pretty much achieve
that goal
the f-135 engine production line is one
of the most mind-blowing marvels of
modern engineering
it's a combination of automated work
instructions
precise machining laser ultrasonic
inspection automated drilling and laser
projection rolled together
some parts of the engine are made in
londale canada and in poland
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the final assembly however takes place
in middletown connecticut in the united
states where in 2014 pratt and whitney
took engine technology a step further by
switching from the vertical to the
horizontal assembly system
this concept had been on trial in the
company's branch in canada
powering the cs series of aircraft
for more benchmarking the team of
engineers also traveled to europe to
study audi corporation's efficient r8
cars horizontal engine model
horizontal aircraft engine assembly
automatically eliminates all the tooling
interfaces leading to increased
productivity
the reliability of this engine was also
proven through the accelerated mission
testing
this testing method is used to rapidly
age an engine by causing it to
accumulate several years of running time
in a short amount of time
allowing for the identification and
correction of issues before they could
occur in normal use
another aircraft that uses pratt and
whitney's engine for propulsion is the
c-17 globemaster a strategic airlift
plane that has rendered heavy service
since it first entered service in 1995.
they use it in a very challenging
environment and the engine delivers day
in and day out they take off from very
short runways and unimproved runways and
having reliable thrust when you don't
have much room is paramount to executing
it boasts four pratt and whitney f-117
pw100 turbofan engines similar to those
used on commercial airliners
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the f-117 engine is the revolutionary
part of a c-17 it had the ability to go
into desert locations and had the the
opportunity to to air drop at very low
altitudes in very austere locations with
horrible weather weather conditions
because the performance of the engine
allowed them to get into those places
the b-52 another aircraft featuring the
jt3d and j-57 engines was essentially
built to carry nuclear weapons for cold
war era deterrence missions
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therefore the ability to save fuel while
airborne was integral to its design
in fact the b-52 continues to be the
only aircraft in service with eight
engines
the interior of the b-52 is still very
revolutionary for its age
the bombay doors open up to reveal a
near empty compartment which can be
stocked with any variety of bombs and
other munitions
along with engine redundancy boeing was
careful to provide plenty of interior
system redundancy to protect against
potential failures
for instance the b-52 features six
engine driven hydraulic pumps
and four electric backup pumps four
generators and two manual emergency
landing gear extension and retraction
systems
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below the cockpit is a tactical mission
area where two operators work to keep
the plane on track while controlling the
aircraft's weapons
the plane was also equipped with the
defensive aerial tail gun
designed as a potential nuclear response
craft it was essential that the b-52 be
able to get airborne very quickly
this led to what's known as the cart
start to execute this launch procedure
the flight crew together with the crew
chief scrambles to the plane where they
remove pre-flight check flags and then
into the craft
explosive charges are then used to fire
up the engines which would normally take
up to one hour to warm up
in most cases however a cart start can
have the b-52 going in 10 minutes
besides the differences in the engine
types and the unique starting methods of
some aircraft another distinct
difference is the engine placement
mini planes manufactured by learjet for
instance feature rear-mounted engines
which are positioned near the tail on
either side of the fuselage
the boeing 727 is also known for this
design as is the boeing 717 the crj 200
to 1000 and the mcdonnell douglas md 8x
series of jetliners
this is in stark contrast to the
majority of large commercial and
military craft like the b-52 and boeing
747 which feature underwing engines
rear-mounted engines are ideal for
protecting against issues related to
engine failure
if one engine were to stall mid-flight
the pilot would have to deal with much
less asymmetric thrust as the engines
are so close to the center line
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when an underwing engine goes out the
resulting yaw can make it difficult for
the pilot to maintain control
unfortunately rear-mounted engines are
also extremely loud for passengers near
the back of the plane
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they also need a horizontal stabilizer
to be placed above them resulting in a
t-tail design
by contrast underwing engines are easier
to service and do not result in the
noise issues associated with their tail
mounted counterparts
this configuration also provides wing
bending relief
which can reduce wing structure weight
and allows for an overall lighter plane
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all in all both designs have their
benefits but who knows the airplanes of
the future may rely on something
different altogether
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that's the end of this video i hope you
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you