hey guys welcome back to Airplane Anatomy a series breakdown different
airplanes from their history to their engineering to how they fly so today in
episode 5 we're going to be talking about one of the most powerful but
elusive aircrafts in the world and that is the Northrop Grumman b-2 spirits now
the b2 was designed originally as a long-range bomber aircraft to carry both
conventional and thermonuclear bombs now in order to do this it needs to be able
to enter and leave enemy airspace without being detected especially by
radar this is also known as stealth so today we're going to dive deeper into in
simplified terms: how does radar work and also how our
planes like the b-2 are engineered for stealth so let's get started
the development of the b2 like many other military airplanes started during
World War two so at that time the US had two main bombers in their fleets the
first was from Boeing called the b-52 Stratofortress that was designed to fly
at such high altitudes that it would be difficult to reach by anti-aircraft
systems and the second one still in development at that time was the
rockwell b-1 lancer which was designed to do the opposite so it was supposed to
fly as such low altitudes and so quickly that it would be difficult to deduct
however both of these airplanes had a big vulnerability to a new technology
that was being developed in the 70s called radar so with radar also came a
new race to build the very first stealth bomber in the world and at that time
Nazi Germany actually came up with a design for such an aircraft called the
Horten ho 229 which was strikingly similar to the eventual designs of the
b2 however thankfully it was never put into service so around 1979 the u.s.
started their advanced technology bomber program or 80b program which led to the
eventual design of the b2 so what was this new groundbreaking technology
called radar and how does it work in simple terms we can use radar to
determine the position the heading and the velocity of an aircraft now radar is
actually an acronym for radio detection and ranging and it might sound very
complex however the concept behind it is actually very simple imagine you're
holding a flashlight in a dark room when you point that light towards an object
the light rays travel from that flashlight to the object and gets
reflected by the object back into your eyes and depending on which light gets
reflected back in how much this tells your brain what shape of the object it
is and how far away it is now similarly radar emit intermittent radio
waves that can travel for many more miles into a larger area an antenna is
then transmitting these waves as a narrow beam in a particular direction
now this is why a lot of antennas actually rotates to tracking movement in
a larger area now these rays continue traveling until they hit something in
which case they will be reflected back now the antenna then can switch to being
a receiver to listen to the radio waves that are returning and since the waves
travel at a constant speed which is the speed of lights we can actually use the
length of time it took for the way to return to calculate how far away that
object is and there are many different types of radar as well for example the
Doppler radar can actually tell you the heading of the plane depending on the
change in frequency from the received wave now this is similar it's your y2
pitch of a fire truck siren changes as it approaches you and drives away from
you now you may have noticed that there is an important assumption that we make
in order for radar to work and that is that the waves gets reflected back to
where they originated from however this is not always the case because there are
ways for objects to actually absorb the radar waves or deflect them away from
where they came from and this forms the concept of stealth one way that the
beats who actually deflects radar waves away from its origin is by using what is
called a continuous curvature design now in this design the radii along each
point on the surface actually changes in order to deflect the waves at all
different directions so this actually means that it required a tremendous
amount of computing power in order to even come up with the simulations for
this design and this was also the reason of why b2 was such an innovative plane
for its time on top of that the engines were actually especially designed to be
embedded within the aircraft with s-shaped engine inlets that were
actually placed on top of the wing instead in order to reduce its radar
signature from the ground now all of this in combination with many other
classified features the B to actually have a reader
signature of just 1.1 square feet about the size of a large bird however all of
these features weren't always active during flights and pilots actually had
to manually press a button labeled a p en pen four penetrates in order to turn
on these features and literally disappear with a button now how cool is
that
two companies competed to produce what would eventually become the b2 the first
was an aerospace manufacturer company called Northrop corporation that paired
up with Boeing in order to compete against the design submitted by Lockheed
and Rockwell so Northrop at the time had actually developed two flying wings by
the name of YB 35 in Y V 49 that were very similar in design to the b2 and so
this was the design that eventually won against Lockheed and Rockwell now the b2
is typically referred to as a flying wing and that is because it doesn't have
a traditional fuselage or even each heel section so on typical airplanes the tail
section contains the rudder which affects yaw movement of the airplane so
without a tail section the beat's who actually relies on what is called a
split rudder system that is located on the outer trailing edges of each wing so
how this split rudder system works is by slowing down basically applying speed
brakes on only one side of the aircraft and essentially creating that yaw
movement this was accomplished by what is called a fly-by-wire system in which
the pilot inputs are interpreted by a computer which then translates them into
a series of actions for each flight surface so in this way the plane
actually behaves as the pilot intends it to you even though some of the physical
flight surfaces might be different
both the design and the production of the beats you were of course carried out
in top secrecy so Northrop actually created front companies to order
materials with and employees also had to get top-secret clearance from a special
branch of the Air Force and also underwent random polygraph tests as they
worked there was also such thing as b2 espionage where two employees of
Northrop actually decided to sell secrets of the b2 program to other
countries so when they were caught one was sentenced to life in prison and the
other 132 years in max security jail so that was definitely a Wikipedia rabbit
hole that I would highly recommend now Congress originally intended to order
132 of b2 planes however at the end of the Cold War they decided to bring that
down to only 21 now this means that on average the cost of development and
production for each plane was around 3.3 billion dollars today however with that
price tag of course the b2 became one of the most powerful stealth bombers today
with its service ceiling of 50,000 feet and it's max cruising speed of 0.9 five
Mach it's also able to stay in the air for six hours without refueling
so this enabled its you at one point to have a crew of two operate a mission for
over 70 hours without needing to touch down on the ground so there is
definitely no dispute that this is a extremely powerful airplane however it
has been a very long time since its original development and of course
technology has advanced so much since then
as a result Northrop Grumman has announced that they are working on a new
stealth bomber by the name of b21 Raider that is to enter service around 2023 and
of course the details around its design and production are highly classified
thank you so much for making it to the end of this video I hope you really
enjoy the b-2 spirit as much as I did and that it's your new favorite stealth
airplane so don't forget to give a like for this video and also subscribe to my
channel I've got a lot of great and content coming up for you guys and I
would love to see a comment from you on what you want me to cover next in my
next episode of airplane Anatomy and so for now I will see you next week
you