- [Jared] In this video, we're gonna learn about a
Black Hawk military helicopter, but not just any Black Hawk. This is a specialized
version called the Pave Hawk. We'll walk through the different
features of the helicopter, the engines on top, the rotors and the flight controls and how they're used to
maneuver the helicopter. (electrical crackling) (bang) This video is sponsored by Ground News. (rousing music) This is a specialized version
of the Black Hawk helicopter. It's called a Sikorsky
HH-60G Pave Hawk. It's owned and operated by
the United States Air Force. It's been in use since the early 1980s. The Pave Hawk helicopter
is meant for combat, search and rescue. So anyone on the ground
that needs to be picked up in a combat zone or in
another dangerous area, the Pave Hawk helicopter can go pick them up and bring them back to safety. The Pave Hawk usually has a crew of four. A pilot, a co-pilot and two
special missions aviators, otherwise an known as flight engineers. Then depending on the mission, they'll have several more
pararescuemen, also known as PJs. It's very common to fly in a formation of two Pave Hawk helicopters. These helicopters have
a connection with NASA at Kennedy Space Center in Florida. For many space launches, Pave Hawk helicopters have been ready just in case something goes wrong and they need to rescue the astronauts. But besides that, missions have been flown
all over the world, including the United States. Central America. Africa. Europe and the Middle East. And Asia. Each helicopter costs around
40 million US dollars. The Pave Hawk is just under 20 meters long and about five meters high. Some of the major parts of the helicopter are the main rotors on top, the fuselage, which is the
body of the helicopter, the cockpit in the front, the cabin right behind, and then in the back, we have the tail. The stabilator, and the tail rotors at the very end. The first thing let's dive deep into is the a fueling of the helicopter. It runs off of jet fuel. Right here is the main fuel tank. And then the auxiliary fuel
tank right in front of it. You can see this one from
the back of the main cabin. The regular Black Hawk helicopter does not have this extra
auxiliary fuel tank. That means that the Pave
Hawk can fly a lot further. There are two ways to
refuel the helicopter. When it's on the ground, they'll use the fueling
connections on the left side. But the Pave Hawk can also
refuel while in flight. There's times they can't land or they're in a hurry
to finish their mission. In this case, they'll use
the air refueling probe. They fly behind another aircraft. This one is called an HC-130J and it carries extra
fuel for the Pave Hawk. At the end of the wing
is the refueling pod. The fuel and connections come
out of the back of this pod. Then the Pave Hawk flies up behind, extends the fuel probe, and carefully connects
it up to the fuel drogue. Fuel can then transfer into the Pave Hawk. They can even at two helicopters
refueling at the same time. Once hooked up, it usually doesn't take
more than 10 or 20 minutes to fill their fuel tanks. This whole process is called
aerial refueling or AR. On rare occasions, the Pave Hawk needs to get
rid of some extra weight by using the fuel dumping tube. This doesn't happen too often, but it's there if they need it. Let's look at some more
details up front here. These are the missile warning sensors, so that you know right away
if missiles are being launched at your helicopter. It's probably a good thing to know. Then there's the radar warning receiver, so you know if you're being
picked up by the enemy's radar. Inside the nose of the helicopter, you'll find the radio compartment with communications gear inside of it. This is the color weather radar, used to detect storms so that
you can hopefully avoid flying into any bad weather. Down towards the bottom is the forward looking infrared camera, which is another way to
help them see at night. On the bottom is the LARS antenna, which stands for "lightweight
airborne recovery system." This is used to help locate
survivors down below. The cockpit is inside of here. The pilot is on the right and
the co-pilot is on the left. There's windows directly
above, but also below as well. This allows for increased visibility while they are in flight. There are plenty of knobs,
switches, and gauges for the pilot and co-pilot to monitor. What we're gonna look at are
the three flight controls. The collective, the cyclic,
and the tail rotor pedals. Later in the video, we'll see how these controls can help maneuver the helicopter. Cool thing about these seats is that they can compress
down in the event of a crash. This will help cushion the landing and hopefully prevent any injuries. On each side of the Pave Hawk
there's usually mounted guns. In most cases, the guns will be the same. On this Pave Hawk, we
have the GAU-2 Minigun. These are operated by the
two special missions aviators in the back. Let's take a closer look at the gun. It has a rotating barrel
assembly on the front. The ammo is stored in the
ammunitions box right here, and then moves up through the ammo belt, up then to the main gun. The ammo loops around several times while it's on its way to being fired. This gun can fire up to
4,000 rounds per minute. (gunshots firing, explosion) The cabin can be accessed by opening up the sliding
doors on the side. Inside the cabin on the
ceiling is the FRIES bar, and that stands for fast rope
insertion extraction system. The bars can extend out to
either side of the helicopter. And then a thick rope called the fast rope is tied at the very end. The PJs can then quickly
slide down to the ground. This is ideal for situations when the Pave Hawk can't
land on the ground. Sometimes we need to bring up survivors back up to the helicopter. In that case, they use the hoist. This is a hydraulically
powered cable system to bring up survivors from the ground. It has a cable length of 61 meters and a weight limit of 272 kilograms. These are chaff and flare buckets, and these are on both
sides of the helicopter. The flare buckets are
the ones facing forward, and there's two more of
them up front as well. When these fire off it
looks like fireworks, but the real purpose is to
confuse any heat seeking missiles and hopefully save the helicopter. The chaff buckets are pointed
up and towards the back. It shoots off tiny bits of
metal into the tail rotor to create chaff cloud. It looks like faint smoke. The intent here is to confuse enemy radar. This area here is called
the aft transition bay, which is basically a place to store more electronic equipment. On the side of the Pave
Hawk, there are a few steps. These are good foot holes to make it a lot easier to climb up on top to perform maintenance
and pre-flight checks on the helicopter. The Pave Hawk has two engines. These are General Electric T-701c engines. They're referred to as turboshaft engines. It brings in air through
the front, heats it up, and then compresses it, which then turns the
shaft down the middle. That's why it's called
a turboshaft engine. Now compare that to a turbojet
engine on an airplane. It brings in air through the
front, compresses it, heats it, and then instead of turning
a shaft down the middle, it takes that hot air and
shoots it out the back. This provides the thrust, which
pushes the airplane forward. Now that's the turbojet engine, but on a helicopter it
doesn't need that thrust to push it forward, that's why it uses two turboshaft engines to spin the shafts, which then work together to
spin the main rotor blades. Now don't forget about the
tail rotors on the very back, they're powered by the same engines. The two engines also turn a shaft that goes all the way
back through the tail and up to the tail rotors. In the middle is the auxiliary
power unit or APU for short. This is the small engine that
provides electrical power for the helicopter. The APU is also responsible for starting up the
main turboshaft engines. In the center, we have
our four main rotors. These are like the wings for a helicopter. When the air is flowing fast
enough they will generate lift. Now you could generate more lift by spinning the blades faster. Some toy helicopters or
drones work this way. However, this is not how
full size helicopters work. The rotors on the top
spin at a constant speed. It doesn't change very much once the engines are
running at full speed. For the Pave Hawk, they spin at 258 RPM or
rotations per minute. The way we generate lift is by changing the pitch of these blades. This affects the angle of attack. When you increase it,
it generates more lift. Do it on all four of the rotor blades and this will cause the
helicopter to go up. Decrease the pitch to generate less lift, which will cause the helicopter to descend or accelerate downwards. The turbo shot engines are spinning these four massive
pieces of metal one way. This causes the main
body of the helicopter to want to spin the other way. If we did nothing to stop this the helicopter would spin out of control. This is the reason we have
the tail rotors in the back. It provides a counter torque, or in other words, a spinning
force in the other direction. This stabilizes the helicopter so it's not spinning uncontrollably. If you come back here and
look at these tail rotors, they are not perfectly aligned. They are tilted by 20 degrees. This makes it so that it
also provides a small amount of lift in the very
back of the helicopter. This helps counteract the
extra weight of the tail. Another thing about the tail rotors is that each of the four blades
can also change their pitch. This changes how much airflow there is. Increase the pitch if you
want to turn to the left. And then decrease the pitch if you want to turn to the right. How about moving the helicopter? So if we wanna go forward or
backward, or left or right, how does that work? First, let me show you the
mechanism in the center here. This is called the swashplate assembly. Here's the main swashplate, the rotor mast, and the four pitch control rods, which are then connected to
each of the four rotor blades. The swashplate can move up or down. This directly affects the pitch
on each of the four blades, but the swashplate can also
will tilt from side to side. This means it will change
the pitch more on some blades than on others. And if you watch it spinning around, each blade is always changing. Let's focus in on just this blade. When it's on the right
side, it's relatively flat. But when it's on the left
side, it's more angled. It's flat. Now it's angled. It's flat. Now it's angled. This means unequal lift on different sides of the helicopter. This is used to maneuver the helicopter in different directions. So in short, the swashplate mechanism is one of the main ways that
you can control a helicopter. One of the hardest
things to understand here is something called gyroscopic precession. And this happens to anything that spins, but it's especially
important to helicopters. So if you wanna pitch
the helicopter forward, you might think we need to apply more lift in the back of the rotor blades. But if we did this, it would actually roll the
helicopter to the left. We apply force and it doesn't take effect until 90 degrees later. To actually pitch the helicopter forward, more lift needs to
happen on the left side. And again, if you've never heard of
gyroscopic precession before, this probably seems a little strange. The good news is that helicopter pilots don't have to be actively
thinking about it, but it's definitely good to understand. Now that we know how the rotors work, let's take a look at the flight controls that you'll find in the cockpit. There are three main ones, and we saw these earlier in the video. The collective, the cyclic,
and the tail rotor pedals. Let's go through what
each one of them does. First, the collective. This moves the helicopter up or down. Pull on the collective, and
this will raise the swashplate. This increases the lift on the helicopter causing it to rise into the air. Push down on the collective, the swashplate goes down and
the helicopter generates less lift to move the helicopter down. The center control is called the cyclic. This is used to move the
helicopter forward, backward, or left or right. Move the control, this will tilt the swashplate
causing an uneven amount of lift on one side, which
then moves the helicopter. This automatically adjusts
for gyroscopic precession. All the pilot has to do is move the cyclic in the direction that the helicopter should go. Down here are the tail rotor pedals, which of course uses the tail
rotors to turn the helicopter to the left or to the right. This is also known as controlling the yaw, or vertical axis of rotation. If we push the left pedal the tail rotor blades pitch increases, which then rotates the
helicopter to the left. Push on the right pedal,
decreases the pitch, which rotates the helicopter to the right. So in summary, you have the collective, which moves the helicopter up or down. The cyclic, which moves
the helicopter forward, backward, or side to side. And then the tail rotor pedals, which rotates the
helicopter left or right. At this point, I just wanna mention that
these three controls, the swashplate assembly, and of course, gyroscopic precession, this is all not unique
to just the Pave Hawk. This is how most
helicopters work in general. The Pave Hawk helicopter
sometimes needs to be transported to another destination. Before this happens, there's some preparations
that need to take place. The four main rotor blades
can actually fold back towards the tail, and
then secured in place. The tail rotors are folded
and also the stabilator. Now the Pave Hawk takes up much less space and can be put inside of another aircraft. This is a C-17. And it can fit two Pave Hawk
helicopters inside of it. Now it's not used as much, but the Pave Hawk also has the ability to fold back the tail as well, which would reduce the size even more for some extreme cases. The HH-60G Pave Hawk has been
flying almost 40 years now. At some point in the near future, it will be replaced by
the HH-60W Jolly Green II. This will provide many
improvements to the electronics, fuel system, engines, the armor plating, and of course, the weapons systems. There is so much to
learn in the world today. When you read the news
from only one source you may be getting just
one part of the story. Ground News has an answer to this problem. This is an informative website and app that lets you compare current events and how they're being covered. Pick a story and then take a look at the Bias Distribution chart, which shows you the news
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app by clicking the link in the description below. My name's Jared. I make 3D
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I'll see you next time. (rousing music)
Good animation, but like many other videos, it explains the 90° lag (also it doesn't have to be exactly 90°, it depends on weight of the rotor blades and their inertia) in cyclic controls incorrectly. It's not caused by gyroscopic precession, but blade flapping and phase lag.
It's somewhat explained in these two posts in r/helicopters.
https://www.reddit.com/r/Helicopters/comments/3sfg3b/phase_lag_or_gyroscopic_precession/
https://www.reddit.com/r/Helicopters/comments/1v6aut/can_anybody_explain_the_90_degree_phase_lag_in/
Pretty good vid actually. Mixes up turbojet and turbofan however