Speaker 1: Welcome to Tech Stuff, a production of I Heart Radios
Speaker 1: How Stuff Works. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with
Speaker 1: How Stuff Works and I Heart Radio and I love
Speaker 1: all things tech and um I've been going on a
Speaker 1: lot of trips lately, both for work and for my
Speaker 1: personal life, you know, going on vacations and stuff, which
Speaker 1: means that I tend to get on planes quite a lot.
Speaker 1: So I thought today we talked about the history of
Speaker 1: airplanes and how airplanes work. I've talked a lot about
Speaker 1: different parts of planes in the past, but after doing
Speaker 1: a quick search, I realized I never really done a
Speaker 1: full episode about how planes themselves work. This is actually
Speaker 1: a pretty tricky field, as it is one that has
Speaker 1: been the subject of a lot of discussion as well
Speaker 1: as misinformation or at least an incomplete explanation of how
Speaker 1: things work, or an incorrect explanation of the how. The
Speaker 1: why tends to be correct, but the how tends to
Speaker 1: be confused, and it has led to jokes and memes
Speaker 1: that ultimately, you know, airplanes work on some sort of
Speaker 1: magic that depends upon us believing that it will work
Speaker 1: sort of like the Peter Pan theory of flight, and
Speaker 1: that's definitely taking things to extremes, and no one really
Speaker 1: believes that. But when you consider all the various explanations
Speaker 1: for what is going on, you can feel like the
Speaker 1: joke might be coming from a pretty sincere place. So
Speaker 1: let's start before we get into the how, with the
Speaker 1: history of flight, because you guys know how much I
Speaker 1: enjoy going into history lessons on this show. This is
Speaker 1: no exception. So there were a lot of people who
Speaker 1: dreamed of mastering flight over the past several hundred years,
Speaker 1: thousands of years actually. Many attempted to emulate the way
Speaker 1: birds fly, which seems pretty understandable. You see birds soaring
Speaker 1: through the sky or darting about, and you think, well,
Speaker 1: what's the secret there? How can we do the same thing,
Speaker 1: And so lots of people tried to emulate that. They
Speaker 1: created various rigs or devices that had moving wings, and
Speaker 1: the thought was that if we could just build wings
Speaker 1: of the right size that can move at the proper
Speaker 1: speed and the proper range of motion similar to that
Speaker 1: of a bird's wings, we too could fly through the sky. Now,
Speaker 1: the name for this type of machine one that has
Speaker 1: movable wings is an ornithopter, and legend has it that
Speaker 1: Arcatas of Tarentum made a wooden bird with this type
Speaker 1: of wing motion back in four hundred b C. And
Speaker 1: you might know from Greek mythology the story of Daedalus
Speaker 1: and Icarus, who are able to fly using man made
Speaker 1: wings attached to their arms, at least they did until
Speaker 1: Icarus flew too close to the sun spoiler alert. Leonardo
Speaker 1: dive and she similarly worked on a few theoretical designs
Speaker 1: that relied upon moving wings in the late fourteen hundreds. UH.
Speaker 1: Some people argue that da Vinci's designs would ultimately lead
Speaker 1: toward the development of the helicopter, but generally speaking, the
Speaker 1: movable wing design remained impractical. It wasn't providing enough lift
Speaker 1: or thrust to actually achieve flight. At best, the machines
Speaker 1: would allow for very short, unimpressive hops, like maybe hopping
Speaker 1: an inch off the ground, and at worst they didn't
Speaker 1: manage to lift up anything at all. However, Leonardo da Vinci,
Speaker 1: along with several other egg heads in history like Galileo
Speaker 1: and Isaac Newton, among many others, would advance our understanding
Speaker 1: of aerodynamics, which is the study of properties of moving air,
Speaker 1: particularly as it has to do with interactions with solid objects.
Speaker 1: By understanding how moving air affects solid objects and vice versa,
Speaker 1: we could start to build working theories on how to
Speaker 1: leverage that knowledge and create a working heavier than air
Speaker 1: flying machine. Now, this work was expanded upon by mathematicians
Speaker 1: and engineers people like John Smeaton, Daniel Bernoulli, and Leonard Euler.
Speaker 1: They explored the relationship between air pressure and air velocity.
Speaker 1: A hoity toity by the name of George Kyley would
Speaker 1: prove to be incredibly important in our understanding. He proposed
Speaker 1: that any working aircraft would need separate systems to provide lift, propulsion,
Speaker 1: and control, something the famous Right Brothers would repeat in
Speaker 1: the early nine hundreds. He also began to move away
Speaker 1: from the ornithopter design to a fixed wing approach for aircraft. So,
Speaker 1: in other words, the wing itself doesn't move with relation
Speaker 1: to the body of the aircraft. It stays fixed in place,
Speaker 1: and other elements are what allow the aircraft to fly.
Speaker 1: You don't have to worry about having the wings move
Speaker 1: in any particular path turn Now, Kayley's work led him
Speaker 1: to the conclusion that the way to produce lift was
Speaker 1: to design a machine that would create an area of
Speaker 1: low pressure above the wing and an area of higher
Speaker 1: pressure below the wing. So above the wing you have
Speaker 1: very low pressure. Comparatively speaking, below the wing you have
Speaker 1: very high pressure. So you've got support under you, right,
Speaker 1: You've got air pushing up against the wing from below
Speaker 1: and not not as much you know, air pressure above,
Speaker 1: So the high pressure beneath would lift the wing up,
Speaker 1: acting as a support in a way. Kayley was specifically
Speaker 1: exploring wing designs that had an arch to them, and
Speaker 1: his ideas were sound and in line with Bernoulli's theorem,
Speaker 1: which describes the behavior of moving fluids. And we have
Speaker 1: to remember that our atmosphere is a fluid. In this sense,
Speaker 1: gases have fluid i movement. Gases are fluids, just as
Speaker 1: liquids are fluids. It this is where a lot of
Speaker 1: sources get things a little muddled, and it's understandable, but
Speaker 1: it ends up being a a fundamental misunderstanding of what
Speaker 1: is going on. So the incorrect explanations tend to be
Speaker 1: right in describing the fact that the reason fixed wing
Speaker 1: flight works is that the movement of the aircraft through
Speaker 1: the air creates an area of low pressure above the
Speaker 1: wing in an area of high pressure below the wing.
Speaker 1: But they often mess up the actual explanation of how
Speaker 1: this is happening, what is actually going on. So let
Speaker 1: me give you the wrong way to describe it first
Speaker 1: and we'll get that out of the way. So typically
Speaker 1: the description starts with the design of the wing itself,
Speaker 1: which is usually described as having a flat bottom and
Speaker 1: a curved upper part, in which the front part of
Speaker 1: the wing, the leading edge, ends up curving up to
Speaker 1: become a bit thicker towards the front of the wing
Speaker 1: and then tapers to ord the back of the wing,
Speaker 1: where the upper surface you know, slopes back down and
Speaker 1: meets the lower surface for the back edge or trailing
Speaker 1: edge of the wing. And if you're looking at the
Speaker 1: cross section of the wing, then you kind of get
Speaker 1: a sideways tear drop shape right the the leading edge
Speaker 1: gets thicker and then tapers back down until it meets
Speaker 1: again at the trailing edge. Um, by the way, the
Speaker 1: technical name for the cross section of a wing is
Speaker 1: an airfoil. Air Foils do not necessarily have to follow
Speaker 1: that shape, but many do. Many early air foils would
Speaker 1: follow that curved design. Now, again, the wrong description for
Speaker 1: what is causing lift states that when the wing moves
Speaker 1: through a fluid, or conversely, when a fluid moves past
Speaker 1: the wing, either way will work. There has to be motion,
Speaker 1: but the motion can work in either way. You can
Speaker 1: either have the fluid moving at a proper speed against
Speaker 1: the solid object. That's the way we test things out
Speaker 1: in wind tunnels. We have a stationary object and we
Speaker 1: blow wind past it, or the object itself can move
Speaker 1: through the fluid, which is the way airplanes work. They
Speaker 1: fly through the air either way. According to this incorrect explanation,
Speaker 1: the air molecules when they hit that leading edge, that
Speaker 1: front edge of the wing, end up splitting into two
Speaker 1: different pathways. Some of the air molecules are traveling over
Speaker 1: the top surface of the wing and some are traveling
Speaker 1: on the bottom surface of the wing. Well, the top
Speaker 1: surface of the wing has that curve to it, which
Speaker 1: means that the air molecules have to travel further from
Speaker 1: the front edge to the back edge right than it
Speaker 1: would on the lower side of the wing because the
Speaker 1: lower side is straight, and as we know, the shortest
Speaker 1: distance between two points is a straight line, So the
Speaker 1: bottom edge of a wing is a straight line to
Speaker 1: go from the leading edge to the trailing edge straight path.
Speaker 1: The if you're going over the top, you have to
Speaker 1: follow that curve, which means you're actually traveling more distance,
Speaker 1: and so that is a longer way to travel. And
Speaker 1: according to this incorrect description of lift, the air molecules
Speaker 1: traveling on top of the wing have to go faster
Speaker 1: than the molecules traveling below the wing, and then they
Speaker 1: meet back up at the trailing edge. So let's say
Speaker 1: you've got air molecule one and air molecule to. Molecule
Speaker 1: one's traveling over the wing, Molecule two is traveling under
Speaker 1: the wing, and they both meet at the far end.
Speaker 1: But in order to do that, molecule one has to
Speaker 1: travel faster than molecule two. And according to bern Newley's
Speaker 1: theorem Daniel Burn Newley, a fast moving fluid is at
Speaker 1: a lower press pressure than a slower moving fluid. So
Speaker 1: says this description, the air pressure above the wing is
Speaker 1: lower than the air pressure below the wing. Now it
Speaker 1: is true that the air pressure above the wing is
Speaker 1: lower and that the air pressure below the wing is higher.
Speaker 1: I keep thinking that I've said this is the wrong way,
Speaker 1: because I'm talking about above and below and higher and
Speaker 1: lower than you flip them right, because everything above the
Speaker 1: wing is a lower pressure, everything below the wing is
Speaker 1: a higher pressure. That part is right. So the destination
Speaker 1: is correct. It's the journey to get there that we've
Speaker 1: got wrong, because, uh, there would need to be some
Speaker 1: reason for the upper and lower air molecules to have
Speaker 1: to travel to arrive at the same destination at the
Speaker 1: same time. But there's no reason for that at all.
Speaker 1: There's no reason why air molecule one and air molecule
Speaker 1: to have to meet back up again at the trailing edge.
Speaker 1: One of them can easily travel faster than the other.
Speaker 1: There's no conservation of velocity between the two. Now, if
Speaker 1: it were true that the air molecules on the top
Speaker 1: and the air molecules on the below had to travel
Speaker 1: at a speed where they would meet up again, that
Speaker 1: that was absolutely necessary. This description would work if that
Speaker 1: were true. If air molecule wanted two had to meet
Speaker 1: on the far end again, this would be an accurate theory. However,
Speaker 1: the flaw in this description goes by the name the
Speaker 1: equal transit theory or sometimes the longer path theory. Now,
Speaker 1: before I explain what is really going on with lift.
Speaker 1: Let's consider for a moment how we know this common
Speaker 1: description is incorrect. First, if this were actually how wings
Speaker 1: would generate lift, it would mean that any plane that
Speaker 1: did not have this wing design would fail to generate
Speaker 1: lift because you wouldn't have that longer path on top. So,
Speaker 1: in other words, if you had a straight wing design
Speaker 1: for your aircraft, there's no way it would be able
Speaker 1: to fly. It could not generate lift if this were
Speaker 1: in fact the only way it worked, and we know
Speaker 1: that's not the case. There are lots of aircraft out
Speaker 1: there to have a flat wing design. A paper airplane
Speaker 1: doesn't have a curved wing, and it can generate lift.
Speaker 1: You just have to give it enough thrust and it
Speaker 1: will fly. It doesn't immediately plummet um. It does lose
Speaker 1: speed because of drag. We'll talk about dragon a little bit,
Speaker 1: and if it loses speed then it's not generating enough
Speaker 1: lift to maintain flight, so it will eventually fall. But
Speaker 1: that's a flat wing and it does work. So flat
Speaker 1: wings can work as well as curved wings, so that
Speaker 1: part is out Further, if that explanation were absolutely true,
Speaker 1: planes with curved wings would never be able to fly
Speaker 1: upside down, because if they were to roll over, and
Speaker 1: the whole reason why lift was generated was because air
Speaker 1: was traveling further on one side than the other and
Speaker 1: then meeting back up with the air molecules, then the
Speaker 1: plane's wings would actually create lower air pressure below the
Speaker 1: plane and higher air pressure above the plane that would
Speaker 1: drive the plane downward. So instead of having lift holding
Speaker 1: the plane up, you would be creating a force that,
Speaker 1: combined with gravity, would pull the plane downward or push
Speaker 1: the plane downward, and you would end up with a
Speaker 1: catastrophic result. But we know that's not the case. Trained
Speaker 1: pilots can fly upside down, and properly designed aircraft, you know,
Speaker 1: aircraft that can withstand the forces of rolling over on
Speaker 1: on to their backs. You can still fly inverted that way.
Speaker 1: So clearly there has to be something else going on here.
Speaker 1: The explanation does not work as it stands, so to
Speaker 1: be clear, the end result of how lift works is
Speaker 1: the same in that a plane's wings do create areas
Speaker 1: of low pressure above and high pressure below the wing,
Speaker 1: but the way they do it is different from the
Speaker 1: explanation commonly given. So, in other words, the common explanation
Speaker 1: gives us the right end result but uses the wrong
Speaker 1: way to get there. So it's sort of like using
Speaker 1: the wrong process to solve a math problem but accidentally
Speaker 1: getting the right answer anyway. Sure, the answer is technically
Speaker 1: what you were looking for. The important part is not
Speaker 1: getting the right answer, it's knowing the right way to
Speaker 1: get to that answer. So let's talk about what's actually
Speaker 1: going on. First. Air does in fact move faster over
Speaker 1: the top edge than the lower edge of the wing,
Speaker 1: much faster. In fact, air molecules traveling over the top
Speaker 1: of the wing will arrive at the trailing edge before
Speaker 1: air molecules traveling on the lower side. So that air
Speaker 1: molecule one and two example I gave before, air molecule
Speaker 1: one is going over the wing, air molecule two is
Speaker 1: going under the wing. Air molecule one is actually going
Speaker 1: to arrive at the trailing edge first. They don't meet
Speaker 1: up again, so there's none of those air molecules splitting
Speaker 1: up at the leading edge meeting at the trailing edge.
Speaker 1: The air molecules traveling beneath the wing are actually meeting
Speaker 1: up with totally new air particles that hit the leading edge.
Speaker 1: Later on, more importantly, a wing deflects air and then
Speaker 1: the way it does so creates the area of lower
Speaker 1: pressure above the wing and the area of higher pressure
Speaker 1: below the wing. You can think of the air below
Speaker 1: a wing as getting compressed or squished, while the air
Speaker 1: immediately above a wing enters into more space than it
Speaker 1: had previously occupied. And this is because we're talking about
Speaker 1: a solid structure moving through a fluid. The difference in
Speaker 1: air pressure is what causes the big change in the
Speaker 1: fluids speed. So, in other words, the change in air
Speaker 1: pressure is what is effect affecting those air molecules speed
Speaker 1: across the wing. It's the opposite of what the equal
Speaker 1: transit theory states, which is that the difference in speed
Speaker 1: causes the change in pressure. Actually, it's the change in
Speaker 1: pressure that causes the difference in speed, and the air
Speaker 1: molecules traveling both on the top side of the wing
Speaker 1: and the bottom will at the end have a downward
Speaker 1: velocity once they leave the trailing edge of the wing.
Speaker 1: So why does the air traveling over the wing move
Speaker 1: downward at the end. If the air molecules moving over
Speaker 1: the top of the wing this curved surface in your
Speaker 1: typical airfoil, why would those air molecules be moving downward?
Speaker 1: I mean surely they would just continue horizontally in a
Speaker 1: straight line right now. It's because in our system we
Speaker 1: still have the atmosphere above the plane to consider that.
Speaker 1: You know, when we're first talking about air pressure around
Speaker 1: the wing, we're looking at the immediate area around the wing,
Speaker 1: but you still have all the rest of the atmosphere
Speaker 1: above the plane to consider. Now, immediately over the wing,
Speaker 1: the air pressure is lower due to the presence of
Speaker 1: this physical object moving through a fluid, or the fluid
Speaker 1: moving across the object, or both, because it's all a
Speaker 1: matter of perspective. But above that you still have all
Speaker 1: that atmosphere a normal air pressure depending on that altitude.
Speaker 1: So all that air is still pushing down on the
Speaker 1: area around the plane, and it starts pushing down on
Speaker 1: that lower pressure air, and that forces that lower pressure
Speaker 1: air downward at the trailing edge of the wing. And
Speaker 1: this brings us to another big important factor and lift
Speaker 1: called down wash, that is the amount of air the
Speaker 1: wing is forcing downward. Now, according to Isaac Newton's third
Speaker 1: law of motion, if you have a mechanical system applying
Speaker 1: force in one direction in a system, and equal opposite
Speaker 1: force applies to that mechanical system, so an airplane, for
Speaker 1: saying air downward, will also experience lift upward. It's equal
Speaker 1: to the amount of force of the air going down.
Speaker 1: This is easier to imagine if we think about a helicopter, right.
Speaker 1: A helicopter has rotors that act similar to the way
Speaker 1: and airplanes air foils works. The rotors rotate in a circle,
Speaker 1: So instead of a plane moving horizontally through a fluid,
Speaker 1: you have this rotor that's rotating around in a circle
Speaker 1: and that forces air downwards, and that creates the lift
Speaker 1: that allows helicopters to fly. Airplane wings do the same thing,
Speaker 1: but it's less obvious to us. Those downward traveling air
Speaker 1: molecules at the trailing edge of a wing are the
Speaker 1: down wash of a plane, and it's a secondary source
Speaker 1: of lift along with that air pressure description I just gave,
Speaker 1: So it's not the primary source. It's secondary, but it
Speaker 1: does contribute to the lift that the plane experiences. Now,
Speaker 1: this is why an airplanes wings aren't perfectly horizontal with
Speaker 1: regard to the body of the plane. If you look
Speaker 1: at an airplane, you will notice that the wings have
Speaker 1: a bit of a to them, so that the leading
Speaker 1: edge of the wing is actually pointed up a little bit,
Speaker 1: and the trailing edge is pointed down a little bit,
Speaker 1: and this creates what we call the angle of attack,
Speaker 1: and the angled wings encourage this down wash effect. If
Speaker 1: you've ever put your hand out into the wind and
Speaker 1: you tilted your hand in different ways and you get
Speaker 1: to that sweet spot where you feel like, oh, well,
Speaker 1: now my hand is staying up because of the angle
Speaker 1: it's at as it's going through the wind, like if
Speaker 1: it's out a car window. By the way, don't do that,
Speaker 1: it's dangerous. But if you were to do that and
Speaker 1: you felt it, you know what I'm talking about the
Speaker 1: same thing with airplane wings. That's why they're at that tilt,
Speaker 1: all right. So that's the explanation of the lift. And
Speaker 1: in a moment I'll talk more about how the right
Speaker 1: brothers or I'm creating a working heavier than air flying machine.
Speaker 1: But first let's take a quick break. Now, I just
Speaker 1: spent a lot of time going over lift. But that's
Speaker 1: just one of the forces that are acting on a
Speaker 1: plane in flight. And I mentioned one other briefly as well.
Speaker 1: There are three other forces that are all acting on
Speaker 1: a plane. So for total you've got lift. That's an
Speaker 1: upward force on the plane. There's thrust that's the forward
Speaker 1: force of a plane then, and you have to have
Speaker 1: your thrust to be strong enough to create an airflow
Speaker 1: around the wings to generate the lift to keep a
Speaker 1: plane in flight. So you need to be moving forward
Speaker 1: enough through the fluid, fast enough through the fluid so
Speaker 1: that you can generate lift, or the fluid has to
Speaker 1: be moving fast enough past you in order to do that. Again,
Speaker 1: it's all a matter of perspective. If a plane moves
Speaker 1: too slowly through the air, it won't create the difference
Speaker 1: in air pressure and down wash sufficient enough to maintain lift,
Speaker 1: So thrust is really important. Drag is a force that
Speaker 1: opposes the forward motion of the aircraft. So this is
Speaker 1: sort of the force that's acting uh in a backward
Speaker 1: motion against the aircraft. It's a mechanical force generated by
Speaker 1: the interaction of a solid body with a fluid, and
Speaker 1: it depends upon the difference in velocity between the solid
Speaker 1: object and the fluid. You experienced drag if you've ever
Speaker 1: been swimming pool. You're just walking through and you feel
Speaker 1: that resistance. That resistance is drag. You're forcing water molecules
Speaker 1: to move around you as you walk through. Uh, friction
Speaker 1: plays a factor in this. There's also a concept called
Speaker 1: induced drag, which involves the way that the air pressure
Speaker 1: is is changing and sort of how that is um
Speaker 1: reconciling at the trailing edge of a wing. But it
Speaker 1: gets really technical, and I figure you guys probably need
Speaker 1: a break after I tackled lift. Suffice it to say,
Speaker 1: drag opposes forward motion. So through aircraft design and propulsion systems,
Speaker 1: we have to overcome drag to maintain a proper forward
Speaker 1: velocity to maintain lift. So we do that with making
Speaker 1: aircraft more aerodynamic, you know, reducing that resistance, and by
Speaker 1: having appropriately powerful engines to propel with enough thrust to
Speaker 1: maintain lift. The fourth force in flight is gravity. This
Speaker 1: is obviously the force pulling downward on the plane. So
Speaker 1: we have thrust that's the forward force, drag which is
Speaker 1: the backward force, lift which is the upward force, and
Speaker 1: gravity which is the downward force. All of these are
Speaker 1: vectors because they all have an amplitude and a direction.
Speaker 1: So aircraft design has to take all of those forces
Speaker 1: into account. All right, So we got the technical description
Speaker 1: of the forces acting on the planes out of the way,
Speaker 1: let's get back to the history of stuff. I'll keep
Speaker 1: in mind that throughout this history description that I'm doing,
Speaker 1: people were still sussing out the nature of lift, as
Speaker 1: is obvious by the fact that we still today have
Speaker 1: textbooks and articles that give an incorrect explanation of what
Speaker 1: is going on, or maybe how I should I should
Speaker 1: say how it is going on now. In the eighteen seventies,
Speaker 1: a couple of engineers, one named Francis h Winham and
Speaker 1: John Browning Is the other built the first wind tunnel
Speaker 1: and that would become a critical component for testing wing
Speaker 1: designs and learning more about the practical effects of those designs.
Speaker 1: More work was done by a dude named Horatio Phillips.
Speaker 1: A lot of really great names in this history. By
Speaker 1: the way, Horatio Phillips built an improved wind tunnel and
Speaker 1: created an airfoil design that would become the basis for
Speaker 1: most wing designs in the following decades. Then we have
Speaker 1: Auto Lelandhall. He was a or Lilonhall. He was a
Speaker 1: German engineer who took Cayley's work and began serious testing
Speaker 1: of various wing designs and angles of attack to find
Speaker 1: out what would work best, what is the most efficient
Speaker 1: way to generate lift? What's the best design and best
Speaker 1: angle to get that effect? And he saw that different
Speaker 1: angles of attack allowed for different results and lift. Angling
Speaker 1: a wing could improve the ability to generate lift up
Speaker 1: to a point, and then beyond a certain angle which
Speaker 1: is around fifteen degrees uh, the ability to generate lift
Speaker 1: would drop off again. So as work became the basis
Speaker 1: for many other engineers who followed, including the Right brothers,
Speaker 1: and Otto himself was no slouch. He built several gliders,
Speaker 1: including biplane gliders, and he began conducting test glide flights,
Speaker 1: both manned and unmanned ones, and he probably went on
Speaker 1: more than two thousand, maybe as many as twenty hundred
Speaker 1: test flights. Tragically, it was during one of those tests
Speaker 1: that he met his end in eighteen nineties six after
Speaker 1: a fatal crash. Next we have Samuel Langley, who was
Speaker 1: an astronomer who seemed to have a pretty promising jump
Speaker 1: on creating a working aircraft. He wanted to use a
Speaker 1: steam powered engine to create the thrust needed to achieve
Speaker 1: the lift necessary for flight, so he built a model
Speaker 1: of a plane smaller than a full scale version, and
Speaker 1: it was an unmanned aircraft and He called it the
Speaker 1: Aerodrome in one so a few years before Auto would
Speaker 1: have his his fatal crash. Langley tested this design and
Speaker 1: the aerodrome flew for about three quarters of a mile.
Speaker 1: At that point the aircraft ran out of fuel steam
Speaker 1: powered aircraft. It was enough to get Langley a sizeable
Speaker 1: grant to try and build a full scale version, but
Speaker 1: unfortunately he discovered his design couldn't scale up because as
Speaker 1: you got larger, you're going to need more power to
Speaker 1: generate the thrust, and more power meant you needed a
Speaker 1: heavier steam engine, and and eventually that that ratio just
Speaker 1: wouldn't work out. The steam engine was just too heavy,
Speaker 1: and so you would need even more power to generate
Speaker 1: enough lift to get the heavier aircraft up, and there
Speaker 1: was no way to have the steam engine actually provide
Speaker 1: the power needed and he ultimately had to abandon his
Speaker 1: design at the plane just needed more lift and it
Speaker 1: could generate front thrust, and thus it could not fly.
Speaker 1: In Octave, Chanut, another great name, published a collection of
Speaker 1: works called Progress in Flying Machines. He collected the wisdom
Speaker 1: and experimental results of numerous efforts throughout the aeronautic societies
Speaker 1: out there and and essentially wrote down everything that had
Speaker 1: been done up to that point in the efforts to
Speaker 1: achieve powered flight. Then we get to Orville and Wilbur
Speaker 1: right the right brothers. They recognized Cayley's wisdom and the
Speaker 1: need for separate systems to provide the lift, thrust, and
Speaker 1: control of the aircraft. They also relied upon Chanut's book
Speaker 1: to help guide their own efforts. They came up with
Speaker 1: their own experiment with regard to controlling a flying body's
Speaker 1: motion through flight, the whole steering part of the equation.
Speaker 1: They believe that by controlling the shape of the wing
Speaker 1: they can control the flight itself, including stuff like roll
Speaker 1: and pitch. So the three types of movement you need
Speaker 1: to know about with aircraft once they're flying in three
Speaker 1: dimensional space are roll, pitch, and yaw. Roll is sort
Speaker 1: of the the tilt, the side to side tilt of
Speaker 1: an aircraft, so whether it's tilting to the left or
Speaker 1: tilting to the right. Um as I'll talk about later,
Speaker 1: this tilting becomes a very important part of steering. Pitch
Speaker 1: is the uh the angle of the nose and the
Speaker 1: tail right. So if if you are um pitching up,
Speaker 1: then the aircraft's nose is at a higher altitude than
Speaker 1: the tail, and the aircraft is climbing pitched down, and
Speaker 1: the nose is at a lower altitude than the tail,
Speaker 1: and the aircraft is descending. And then yaw involves turning
Speaker 1: to the left or to the right, although yaw and
Speaker 1: roll are very very important components for steering. Anyway, those
Speaker 1: are the three ways of thinking about the three different
Speaker 1: axes of flight controls in three dimensional space. So we'll
Speaker 1: come back to that in a little bit. So anyway,
Speaker 1: the Right brothers said, all right, well, by manipulating the
Speaker 1: shape of the wing, we can add steering to an aircraft. Um.
Speaker 1: They built several gliders, both unmanned and manned gliders, and
Speaker 1: tested different wing shapes and designs, including in wind tunnels,
Speaker 1: and they worked on perfecting that. And this brings us
Speaker 1: to another important component of the design. Getting up in
Speaker 1: the air is one thing, but from that point on,
Speaker 1: how do you control where you're going? Right? How do
Speaker 1: you actually maneuver a solid object through the air that
Speaker 1: three dimensional space there's no ground to brace against, and
Speaker 1: how do you steer the darn thing? And that was
Speaker 1: what the Right brothers were really working on. In those
Speaker 1: early tests trying to determine the most effective way to
Speaker 1: control the flight of an aircraft once it's airborne. So
Speaker 1: we'll talk about that for a second. Steering something means
Speaker 1: you have to be able to control the direction in
Speaker 1: which that something is traveling. It's very basic and obvious observation,
Speaker 1: but I feel like we have to start somewhere. So
Speaker 1: you need to be able to change the object's velocity
Speaker 1: because velocity is a vector. Again, a vector is something
Speaker 1: that has both an amplitude and a direction, has an
Speaker 1: amount and a direction associated with it. So even if
Speaker 1: the speed of the moving object doesn't change, it's moving
Speaker 1: at the same rate of travel even as you change
Speaker 1: its direction. If you change the direction, you've also changed
Speaker 1: the velocity because the direction part of a vector has changed. So, uh,
Speaker 1: that's an important thing to remember that a velocity can
Speaker 1: change even if the speed stays the same because you've
Speaker 1: changed the direction of travel. Tilting the plane having one
Speaker 1: wing dip lower than the other side means that some
Speaker 1: of the lift acting on the plane is now actually
Speaker 1: pushing the plane in a sideways motion. So when you
Speaker 1: roll the plane a little bit, you are actually changing
Speaker 1: the lift dynamics, and some of that lift that otherwise
Speaker 1: would be holding the plane up is pushing the plane
Speaker 1: to UH to a side. It creates centripetal force, and
Speaker 1: it eventually will make the plane move in a circular path.
Speaker 1: You know, the more the dramatic the roll up to
Speaker 1: a point, the more tight that circle is going to be. However,
Speaker 1: this is, by the way, as known as banking. When
Speaker 1: you talk about airplanes banking, it's because they're they're tilting
Speaker 1: this way and the rolling and UH starting to turn.
Speaker 1: But another thing you have to remember is this reduces
Speaker 1: the amount of lift actually holding the aircraft up. So
Speaker 1: you know, you're dedicating some of the lift to turning
Speaker 1: the aircraft, not just holding it up. So if you
Speaker 1: don't do anything, if you're maintaining the same speed, you're
Speaker 1: changing the velocity by changing the direction. That reduction in
Speaker 1: lift means that your aircraft is going to start to
Speaker 1: lose altitude, So you've got to do something to counteract that.
Speaker 1: Typically you do something like increase the angle of attack
Speaker 1: of the wings or using the tail u to compensate
Speaker 1: for this loss of lift of upward lift so that
Speaker 1: you don't lose altitude. Modern aircraft do this with a
Speaker 1: flight control surface called an elevator, often on the tail,
Speaker 1: and the elevator can adjust its angle to change the
Speaker 1: angle of attack with the fluid that the aircraft is
Speaker 1: moving through the air itself and provide more upward lift.
Speaker 1: Other movable control surfaces can affect the plane's pitch, um
Speaker 1: and the yaw. The yaws typically a it's a rudder
Speaker 1: that's attached to the tail of a plane, and steering
Speaker 1: actually involves controlling the roll and yaw of the aircraft.
Speaker 1: So you have both the yaw and the tilt of
Speaker 1: the plane that allows you to make more controlled turns
Speaker 1: with the aircraft. Each of these systems has its own controls,
Speaker 1: and in modern aircraft uh the ailerons controlled the role.
Speaker 1: These are on the outer rear edge of the wings
Speaker 1: and they can move in opposite directions. So if you
Speaker 1: ever sat on window seat that's right next to a
Speaker 1: wing and you see this little thing at the very
Speaker 1: end of the planes wing and it's either tilting down
Speaker 1: or it's tilting up, that's part of this system that's
Speaker 1: meant to control the role of the plane and allow
Speaker 1: for turns. Um. The yaw, like I said, comes from
Speaker 1: the plane's rudder. It's typically a vertical tail fin that
Speaker 1: can swivel left or right, and the pitch comes from
Speaker 1: the elevators like I mentioned earlier, those are typically on
Speaker 1: the aircraft's tail as well, on a horizontal plane, not
Speaker 1: a vertical plane, like the rudder is, and the elevators
Speaker 1: can also tilt up or down, decreasing or increasing lift
Speaker 1: on the tail, which makes the airplane behave a little
Speaker 1: bit like a lever. Right. If you increase the lift
Speaker 1: on a tail, then the tail gets lifted up and
Speaker 1: the nose the airplane gets tilted downward, and vice versa.
Speaker 1: But that's just one part of the equation, or really,
Speaker 1: I guess you could say two parts of the equation,
Speaker 1: because wing design contributes to both flight control and lift.
Speaker 1: But they also needed to work on thrust. They needed
Speaker 1: a propulsion system that we get their aircraft up to
Speaker 1: a sufficient speed to generate the lift needed to sustain flight.
Speaker 1: They had bill gliders and done manned and unmanned tests
Speaker 1: at Kitty Hawk, North Carolina. They chose Kittie Hawk, by
Speaker 1: the way, they were not natives to North Carolina, but
Speaker 1: they chose kitty Hawk because it was pretty dependable for
Speaker 1: some good winds due to being on the Atlantic coast,
Speaker 1: so um you get a good stiff breeze over at
Speaker 1: Kittie Hawk. I've been there, and one of the most
Speaker 1: popular activities over at Kittie Hawk is kite flying. A
Speaker 1: lot of people flying kites, big elaborate ones way up
Speaker 1: in the sky because they get these nice strong winds.
Speaker 1: By the way, if you get a chance to visit
Speaker 1: Kitty Hawk and to go visit the site of the
Speaker 1: first flight from the right Brothers, I highly recommend it.
Speaker 1: It is a very interesting location, a lot of cool
Speaker 1: information there, and you can actually walk the pathway of
Speaker 1: those test flights. It's pretty neat any way. As part
Speaker 1: of this work, the brothers had designed a movable tail
Speaker 1: component that would help with the flight stability, particularly when
Speaker 1: the pilot of the glider wanted to steer. And now
Speaker 1: it was time to work on an aircraft capable of
Speaker 1: generating its own thrust to maintain flight, not just to
Speaker 1: be able to glide, and this required a lot more research,
Speaker 1: as the brothers had to not only design a motor
Speaker 1: that could turn a propeller fast enough to generate enough thrust,
Speaker 1: but also an airplane frame capable of both supporting the
Speaker 1: motor's weight and to withstand the vibrations the motor created
Speaker 1: during operation. The result of all their research was the
Speaker 1: design of an aircraft they simply called the Flyer, and
Speaker 1: some people refer to it as the Right Flyer. A
Speaker 1: bicycle mechanic named Charles Taylor would build the motor for
Speaker 1: the Brothers. It was a custom built motor, a gasolene
Speaker 1: fueled twelve horsepower motor, and the motor was used to
Speaker 1: drive a chain that in turn would link to gears
Speaker 1: that would turn the two propellers, So it's like a bicycle,
Speaker 1: you know, a bicycles wheels. The propellers were changed driven
Speaker 1: this motor. Through powering the propellers would provide the needed thrust.
Speaker 1: The Right Flyer had a wingspan of twelve point two
Speaker 1: meters or forty point three feet, and the right wing
Speaker 1: was four inches longer than the left wing. So why
Speaker 1: is that? Why was the right wing longer? Well, that
Speaker 1: was because the Right Brothers design meant that the engine
Speaker 1: for the plane would sit a little to the right
Speaker 1: of the center line. It was not centered along the
Speaker 1: axis of the airplane. It actually went a little to
Speaker 1: the right side that meant the pilot would actually laid
Speaker 1: down on the left side of the center line. But
Speaker 1: the engine weighed seventy seven point one ms or a
Speaker 1: hundred seventy pounds, the pilot weighed only sixty five point
Speaker 1: eight kilograms or one five pounds, So the brothers needed
Speaker 1: some way to balance the scales as it were, so
Speaker 1: that the plane would fly properly without the constant need
Speaker 1: for adjustment. Since had a heavier engine on one side
Speaker 1: and a lighter pilot on the other, and so they
Speaker 1: made the right wing a little longer than the left
Speaker 1: in order to generate a bit more lift than the
Speaker 1: left side and thus compensate for the added weight on
Speaker 1: the right side of the plane. The Right brothers held
Speaker 1: the first test flight on December seventeenth three. Orville Right
Speaker 1: was the pilot, and the plane lifted off the ground
Speaker 1: and traveled about one twenty feet or thirty five meters.
Speaker 1: It flew just twelve seconds, but it was enough to
Speaker 1: secure the Right brothers the acknowledgement that they had created
Speaker 1: the first heavier than air manned, steerable flying machine. They
Speaker 1: would build other aircraft based off that design, but the
Speaker 1: only one they ever attempted to preserve was the original
Speaker 1: Right Flyer, and for a short while that airplane called
Speaker 1: the Kensington Science Museum in London home. But in nineteen
Speaker 1: the Flyer returned to the United States to become part
Speaker 1: of the Smithsonian's exhibits, and it is now in the
Speaker 1: National Air and Space Museum in Washington, d C. When
Speaker 1: we come back, I'll talk about some other elements of
Speaker 1: aircraft and how those contribute to flight. Okay, so the
Speaker 1: Right Brothers were two of the many pioneers of piloted
Speaker 1: heavier than air aircraft. There were lots of other people,
Speaker 1: and I hope I've made it clear that the success
Speaker 1: of the Right Brothers depended heavily on the research and
Speaker 1: work of numerous people before them. Also, they weren't the
Speaker 1: only ones working on the problem when they achieved their
Speaker 1: success in North Carolina. It's why I define their successes
Speaker 1: being the first to pilot a heavier than air aircraft
Speaker 1: that had at least some rudimentary flight controls, because otherwise
Speaker 1: you have to talk about a whole bunch of people
Speaker 1: who did lighter than air aircraft and and some other stuff,
Speaker 1: and many people would quickly follow in the footsteps or
Speaker 1: flight steps of the right brothers building better aircraft with
Speaker 1: more sophisticated control mechanisms and development and innovation were in
Speaker 1: the fast lane. So just going to cover a few
Speaker 1: more basics, and I might have to do a future
Speaker 1: episode to talk about some of the more modern systems
Speaker 1: aboard aircraft, because that would make this show run way
Speaker 1: too long if I were to keep up with that.
Speaker 1: So let's talk about propellers. The propellers on a prop
Speaker 1: plane are effectively doing the same thing that the wings
Speaker 1: do on a plane by creating lift, only in this case,
Speaker 1: the direction of the lift is forward with respect to
Speaker 1: the plane. It's like a helicopter's rotors. Moving the blades
Speaker 1: of a propeller in a circular path at a fast
Speaker 1: enough rotational speed creates the force and drives the aircraft forward.
Speaker 1: But unlike a wing, which tends to have a fixed
Speaker 1: angle of attack across the entire length of the wings surface,
Speaker 1: a propeller blade has a twist in it so that
Speaker 1: the pitch angle varies along the length of the blade.
Speaker 1: Some modern planes have a controllable pitch propeller, which allows
Speaker 1: the pilot to change this rotation in order to have
Speaker 1: the plane perform at optimal efficiencies at different air speed
Speaker 1: eads now Jet engines are different, and I've covered them
Speaker 1: in past episodes, but here's a quick rundown. From the outside,
Speaker 1: a jet engine looks like a tube. If you look
Speaker 1: at one head on, you'll see a big fan thing
Speaker 1: in the front of that tube. Then at first you
Speaker 1: might think that a jet is similar to a propeller plane,
Speaker 1: that it's generating forward thrust by just rotating that fan
Speaker 1: super fast. But that's not quite right. The purpose of
Speaker 1: the fan is to suck air into the jet engine.
Speaker 1: The fan attaches to a shaft and it spinds rapidly
Speaker 1: and it pulls air into the engine. Behind the fan
Speaker 1: on that same shaft, or on a shaft around the
Speaker 1: fans shaft, there are a bunch of other blades attached,
Speaker 1: and these blades are compressors. They compress the air. They
Speaker 1: squeeze that air down into a smaller and smaller space.
Speaker 1: That also increases the pressure obviously of the air, and
Speaker 1: also the temperature of the air and gets it to
Speaker 1: the right temperature for the next stage, which involves combustion.
Speaker 1: So behind the compressor is a combustion chamber or series
Speaker 1: of combustion chambers, and the compressed air enters into the chambers,
Speaker 1: and nozzles that also enter the chambers spray a fine
Speaker 1: mist of fuel there, and an ignition component creates an
Speaker 1: electric spark that lights the mixture of compressed air and fuel,
Speaker 1: and you get burning gases inside the chamber. Those burning
Speaker 1: gases expand as the heat up. The only exit out
Speaker 1: of this engine is a nozzle at the back, So
Speaker 1: the expanding gases escape out the nozzle at a tremendous
Speaker 1: amount of force. And because we know every action has
Speaker 1: an equal but opposite reaction, we know that this backward
Speaker 1: pushing force of escaping gas creates a forward pushing force
Speaker 1: on the aircraft itself. So if you can generate enough
Speaker 1: force to overcome the weight of the jet and get
Speaker 1: it up to speed, you can use it to provide
Speaker 1: the thrust needed to get lift and take off. Oh
Speaker 1: and that escaping gas also turns a turbine at the end,
Speaker 1: So you've got the combustion chamber, you've got an exit
Speaker 1: out the back of the combustion chamber where the gas
Speaker 1: is passing through a nozzle. It also ends up turning
Speaker 1: a turbine, and that turbine provides the rotational force for
Speaker 1: the UH, the compression blades on that rotating shaft, and
Speaker 1: also the fan. You know I mentioned those earlier. That's
Speaker 1: what's actually causing the rotational force. So not only does
Speaker 1: the jet engine provide thrust for the aircraft, it also
Speaker 1: harnesses some of that energy to operate the components of
Speaker 1: the engine itself. There are variations on this design. There
Speaker 1: are two or three spool jet engines, for example, but
Speaker 1: they all work on the same basic principle. UM. One variation,
Speaker 1: the one we see in commercial jets. A very popular
Speaker 1: one is the turbo fan jet. In this version, the
Speaker 1: engine casing is much larger than the combustion section, so
Speaker 1: you can think of it as a big tube around
Speaker 1: a much smaller tube. The smaller tube is the combustion part.
Speaker 1: So you've got the fan that's pulling air in, You've
Speaker 1: got the compressor blades that are compressing the air down,
Speaker 1: but there's also space for the for some of that
Speaker 1: air to pass along the outside of the combustion chamber,
Speaker 1: so some air is kind of going in between the
Speaker 1: combustion chamber and the casing for the jet engine itself,
Speaker 1: and the air coming in is compressed and most of
Speaker 1: that air is passing along the outside of the engine
Speaker 1: that provides the majority of the thrust. It's not the
Speaker 1: superheated stuff. It's this compressed air that's passing through this
Speaker 1: bleed bypass UH section. And it also not just provides thrust,
Speaker 1: but it also is able to cool the engine so
Speaker 1: that remains in operating operating temperatures. It it avoids overheating,
Speaker 1: so the air that passes through the engine still goes
Speaker 1: through the same combustion process I mentioned earlier and provides
Speaker 1: additional thrust as it escapes, plus provides the UH the
Speaker 1: force necessary to rotate that turbine and keep everything in motion.
Speaker 1: By the way, jet engines can also be used to
Speaker 1: power stuff other than aircraft, or rather, I should say
Speaker 1: turbine engines like this can be used to power stuff
Speaker 1: like tanks, or they can help power helicopters. They don't
Speaker 1: do it the exact same way as a jet plane,
Speaker 1: which has this exhaust be part of the thrust mechanism.
Speaker 1: Instead the tail end of that engine, there's another turbine
Speaker 1: that connects to some sort of drive mechanism, such as
Speaker 1: the tank's treads or helicopters rotors. So the the turbine
Speaker 1: engine pulls air in, you've got the combustion. All of
Speaker 1: this is used to create the energy needed to rotate
Speaker 1: a different turbine that then sends that power onto the
Speaker 1: propulsion system of the tank or the helicopter. Uh. These
Speaker 1: engines also have to have an exhaust port for all
Speaker 1: that hot air to escape, but it's not used like
Speaker 1: a thruster on a jet plane. But hey, for these
Speaker 1: engines to work, you still got to get that turbine
Speaker 1: spinning right. And that presents a challenge because these are
Speaker 1: engines that work fine while the jet is in operation,
Speaker 1: while it's actually moving through the air, because the process
Speaker 1: of the jet engine working provides the energy needed to
Speaker 1: turn the turbine that pulls more air in through the system.
Speaker 1: By the way, you're not generating more energy than you're
Speaker 1: expending here, I want to make that clear. Just rather
Speaker 1: that the process is not just providing thrust, but providing
Speaker 1: the force needed to turn those turbines and those fan
Speaker 1: blades and compressor blades. But in order to do that,
Speaker 1: you have to get up to speed in the first place.
Speaker 1: How do you get it started? Well, the turbines are
Speaker 1: too heavy and need to turn too quickly to rely
Speaker 1: upon an electric motor to do it. So you can't
Speaker 1: just have an electric motor attached to this thing to
Speaker 1: jump start the turbine engine. That's not going to work.
Speaker 1: They're far too large and heavy. So to do it,
Speaker 1: you have to feed compressed air into a stopped jet
Speaker 1: engine to get things started, to start turning those fan blades,
Speaker 1: and to get enough air pressure in there for you
Speaker 1: to ignite the combustion chambers. Now, if everything is working
Speaker 1: properly on the aircraft, you can use a system called
Speaker 1: the auxiliary power unit or APU to do this. Um
Speaker 1: it supplies the jet engine with compressed air, and you
Speaker 1: can start with just one engine. I'll explain how in
Speaker 1: a minute. So the APU is typically at the far
Speaker 1: end of a jet, on the main body of the jet,
Speaker 1: the fuselage. It's at the very end, and it has
Speaker 1: three main functions. One of those is the main engine
Speaker 1: start sequence, but the other two big functions are to
Speaker 1: supply electrical power to the jet. There's a turbine in
Speaker 1: this jet engine that is connected to a generator, and
Speaker 1: thus you can use that to help supply electrical power
Speaker 1: to the jet, and also it can provide bleed air
Speaker 1: pressure for the air conditioning system bleed air pressure. Think
Speaker 1: of the bleed air system as kind of plumbing. It's
Speaker 1: a series of conduits or pipes in a jet that
Speaker 1: allow compressed air to pass through. So the APU itself
Speaker 1: is a small turbine engine similar to a jet engine.
Speaker 1: There's an intake panel it slides open. It allows air
Speaker 1: to come into the system. And the APU, unlike the
Speaker 1: main engines, is small, so you can actually start it
Speaker 1: under battery power. You can have an electric motor attached
Speaker 1: to the APU. You turn it on. This starts the
Speaker 1: fan in the APU spinning, which then draws air in.
Speaker 1: And like turbofan engines, the APU has bleed air, so
Speaker 1: air that goes around the engine itself and it enters
Speaker 1: into this bleed air pathway system that connects to other
Speaker 1: components of the jet. So you divert some of the
Speaker 1: air going through the APU to enter the jet itself
Speaker 1: through this bleed system, and the pressurized air goes to
Speaker 1: a component called the air turbine starter, and this connects
Speaker 1: to the engine's shaft through a clutch mechanism um and
Speaker 1: that allows the APU to provide compressed air to start
Speaker 1: turning the fan and turbine in a jet engine. And
Speaker 1: this reminds us about fluid dynamics. You can either have
Speaker 1: a solid object moving very quickly through relatively still fluid,
Speaker 1: or fast moving fluid moving past a relatively still solid object,
Speaker 1: and you'll get the same results. So pushing compressed air
Speaker 1: through the main engine creates a situation similar to the
Speaker 1: engine operating at flight speed. So once the engine reaches
Speaker 1: a certain percentage of its top revolutions per minute, somewhere
Speaker 1: around twenty eight, the air inside is compressed enough to
Speaker 1: sustain combustion, and the engine will ignite fuel in the
Speaker 1: combustion chambers and that will provide the energy necessary to
Speaker 1: take over from there, and the engine will perpetuate its
Speaker 1: own rotation and you can stop pumping compressed air into
Speaker 1: the system. From that point. You can use the APU
Speaker 1: to power up the second engine, or you could even
Speaker 1: use the first engine to do it, because the engine
Speaker 1: system feeds into this bleed air system. So again it's
Speaker 1: like you know plumbing. You've got all these conduits, you
Speaker 1: also have all these valves in that system that either
Speaker 1: allow air to pass through or prevent air from going there.
Speaker 1: So when you're starting up engine one, you would have
Speaker 1: all the other valves closed so that the compressed air
Speaker 1: can only follow one pathway to get to that engine. Now,
Speaker 1: sometimes the APU isn't you know, totally working and can't
Speaker 1: supply enough compressed air to do the job. In those cases,
Speaker 1: the ground crew will connect a land based air compressor
Speaker 1: that's technically known as an air start unit, but most
Speaker 1: folks refer to it by a more informal name, the
Speaker 1: huffer cart, And the hover cart sends huffer is h
Speaker 1: U F F E R. It sends compressed air into
Speaker 1: the bleed system of a jet. So you just plug
Speaker 1: it into that bleed system and it provides the compressed air.
Speaker 1: And again the valves leaning to one engine are all
Speaker 1: open and the other valves are all closed. And once
Speaker 1: that first engine has started up and reaches the proper
Speaker 1: rotational speed, which is somewhere around the mark, that engine
Speaker 1: can provide the compressed air to start the other engine
Speaker 1: or engine two. There might be multiple engines on the jet,
Speaker 1: like four engines or something. You can keep doing this
Speaker 1: process over and over. Now, I honestly didn't know any
Speaker 1: of that stuff about how jet engines start from from
Speaker 1: a stopped position. Before I researched this episode, I understood
Speaker 1: how jet engines worked, but I didn't know how they
Speaker 1: got them started. So I always wondered how that happened,
Speaker 1: since it seemed like the kind of system that only
Speaker 1: works once it's already working, which seems like a catch
Speaker 1: twenty two, Like a building that issues permits, but the
Speaker 1: only way to get inside the building is to already
Speaker 1: have a permit. So how can you start the jet
Speaker 1: engine in the first place? And now I know, so,
Speaker 1: now you know too. So those are the basics of flight, thrust, lift,
Speaker 1: and flight controls. And granted I spent the least amount
Speaker 1: of time on flight controls, I may need to do
Speaker 1: a future episode to talk more about that in radar detail,
Speaker 1: to describe the physics behind them and how modern flight
Speaker 1: control systems work. In the meantime, I do have a
Speaker 1: lot of older episodes that go into things like jet engines, scramjets,
Speaker 1: autopilot systems, and more. It's actually kind of silly that
Speaker 1: took me this long just to cover the basics of flight.
Speaker 1: That one's on me. If you guys have suggestions for
Speaker 1: future episodes of tech Stuff. You can get in touch
Speaker 1: with me s me An email the addresses tech Stuff
Speaker 1: at how stuff works dot com. Pop on over to
Speaker 1: our website that's tech stuff podcast dot com. There you're
Speaker 1: going to find an archive of all of our older episodes,
Speaker 1: plus links to our social media presence, and a link
Speaker 1: to our online store where you can buy tech stuff
Speaker 1: merch and every purchase you go and make ends up
Speaker 1: helping our show. We greatly appreciate it. I hope you
Speaker 1: like the designs. Trying to get some new ones in
Speaker 1: there soon and I will talk to you again really soon.
Speaker 1: Text Stuff is a for auction of I Heart Radio's
Speaker 1: how Stuff Works. For more podcasts from my heart Radio,
Speaker 1: visit the i heart Radio app, Apple Podcasts, or wherever
Speaker 1: you listen to your favorite shows.