Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff Works dot com. 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 in I heart radio and I love
Speaker 1: all things tech and guys. I travel a decent amount,
Speaker 1: but I do not hold any special frequent flyer status
Speaker 1: with any airline. I have had the amazingly good fortune
Speaker 1: to sit up in business class a dozen times or so,
Speaker 1: even on international flights, which is amazing. But I've never
Speaker 1: ever flown on one of the most prestigious aircraft to
Speaker 1: have graced the skies. I never had the chance to
Speaker 1: do it on the Concorde. The Concorde took its first
Speaker 1: flight way back in nineteen sixty nine. It was a
Speaker 1: test flight. It would be several more years before it
Speaker 1: would go into passenger service. It would even be a
Speaker 1: few years before we make its first transatlantic flight. But
Speaker 1: if we take the date of its first flight as
Speaker 1: the Concord's birthday, which I would argue is a pretty
Speaker 1: arbitrary thing, but go with me. The famous aircraft celebrated
Speaker 1: turning fifty on March second, two thousand nineteen. Because March
Speaker 1: second nineteen sixty nine is when it first took flight,
Speaker 1: But then the aircraft has also been out of service
Speaker 1: for more than a decade. So in this episode, we're
Speaker 1: going to learn about the Concorde aircraft, what made it special,
Speaker 1: how it worked, and why they aren't zipping all over
Speaker 1: the place today. Now you all know I am physically
Speaker 1: incapable of doing an episode without a history lesson being involved,
Speaker 1: and this episode is no different. So to understand the
Speaker 1: story around the Concorde, we actually have to go back
Speaker 1: two decades before the Concorde ever took to the skies,
Speaker 1: to a very special day. That day would be October nineteen.
Speaker 1: That's when Captain Charles E. Chuck Yeager took controls of
Speaker 1: an experimental aircraft, the Bell X one, a B twenty
Speaker 1: nine bomber carried the X one up to twenty thousand
Speaker 1: feet of altitude before releasing the jet from the bombay doors,
Speaker 1: and that is when Yeager made history. Now, Yeager he
Speaker 1: wasn't in tip top shape because he had been in
Speaker 1: a horseback riding accident and he neglected to tell anyone
Speaker 1: about it because he didn't want to get taken off
Speaker 1: the test flight. He probably suffered a tiny bit of
Speaker 1: discomfort during this flight because two of his ribs were broken.
Speaker 1: So imagine not only being the first pilot to try
Speaker 1: and control a rocket powered aircraft capable of going at
Speaker 1: unprecedented speeds, but also doing so with your torso screaming
Speaker 1: at you in pain. The X one's engine was a
Speaker 1: Reaction Motors x l R eleven rocket engine. Before long,
Speaker 1: Yeager was passing mock zero point eight five that represented
Speaker 1: the fastest speeds that engineers could simulate in wind tunnels.
Speaker 1: At that time. It was the literal truth that no
Speaker 1: one was really sure what might happen next. Mock speed,
Speaker 1: by the way, refers to the ratio of the speed
Speaker 1: of a body like a jet, to the speed of
Speaker 1: sound in the undisturbed medium through which the body is traveling.
Speaker 1: So if a body a jet is going at the
Speaker 1: same speed that sound travels through that medium, this being
Speaker 1: the air, you would say it was traveling at mock one,
Speaker 1: it's traveling at the same speed as the speed of
Speaker 1: sound through that medium. Any number greater than one indicates
Speaker 1: that the body the jet is traveling faster than sound
Speaker 1: through that particular medium. So Yeager pushed the X one
Speaker 1: past Mock one, reaching Mock one point zero six at
Speaker 1: forty three thousand feet of altitude. As his top speed
Speaker 1: and interesting stuff was starting to happen, shock waves formed
Speaker 1: over the top surface of his wings and just ahead
Speaker 1: of the nose of the jet. The shock wave is
Speaker 1: an important component of this story because it relates to
Speaker 1: sonic booms, something the Concorde would have to deal with
Speaker 1: decades later, and it means we have to talk a
Speaker 1: bit more about sound. So sound propagates through the air
Speaker 1: as changes in air pressure, fluctuations in air pressure rapid fluctuations.
Speaker 1: As the Mock one description tells us, sound travels at
Speaker 1: a fixed speed depending upon the medium it's traveling through.
Speaker 1: So sound travels at different speeds through different types of media.
Speaker 1: Sound traveling through water will move at a different rate
Speaker 1: than sound traveling through air, but within a single medium
Speaker 1: under similar conditions, it will always travel at a fixed speed. Now,
Speaker 1: this means a body moving through a medium can actually
Speaker 1: catch up to the sound waves it is producing as
Speaker 1: it moves. So let's say you are running down the
Speaker 1: road at an incredible speed and you're singing a song
Speaker 1: at the top of your lungs, and let's say for
Speaker 1: the purposes of this example, the song is bird House
Speaker 1: in your Soul, by they might be giants. The faster
Speaker 1: you run, the more you catch up to the sound
Speaker 1: waves of your singing. And if you run fast enough,
Speaker 1: like at around seven hundred seventy miles per hour at
Speaker 1: sea level under normal atmospheric conditions, you are moving at
Speaker 1: the same speed as those sound waves. They're just building
Speaker 1: up right in front of you, and you're keeping speed
Speaker 1: with them. A person ahead of you wouldn't hear you
Speaker 1: singing until you were right next to them, and then
Speaker 1: the sound waves would hit them. Even if they saw
Speaker 1: you running toward them from really far away, they wouldn't
Speaker 1: hear you till you were right there. The sound can't
Speaker 1: travel faster than seven seventy miles per hour. So there
Speaker 1: you are, You're Berry Allen, and you're singing your heart
Speaker 1: out while you're running as fast as you can. But
Speaker 1: then you realize, oh, I think I could actually run
Speaker 1: a little faster. Heck with it, I'm I'm gonna really
Speaker 1: turn up the speed, So you pour it on, you
Speaker 1: crank it up beyond mock one. Now you're actually out
Speaker 1: running the sound waves that you are making the song
Speaker 1: you're singing is literally trailing behind you, and as you
Speaker 1: break through those sound waves, you're actually breaking the sound
Speaker 1: barrier itself. You're breaking through a pressure wall of air pressure.
Speaker 1: And since sound through the air is all about air pressure,
Speaker 1: a really interesting thing happens. There's a pressure collapse, Air
Speaker 1: rushes in to fill a sudden low pressure, and there
Speaker 1: is a sonic boom. It's essentially the sound of an
Speaker 1: explosion allowed cracking noise. So you're running and you're singing,
Speaker 1: you are the flash. People standing on the road up
Speaker 1: ahead of you can see you there, see that you're
Speaker 1: zooming towards them at an incredible speed, but they don't
Speaker 1: hear you, and they don't even hear you when you're
Speaker 1: right next to them. If you could take a snapshot
Speaker 1: of the instant you run right next to these people,
Speaker 1: they wouldn't have heard anything yet. It's only after you
Speaker 1: have passed, when the sound waves you've emitted catch up
Speaker 1: and that pressure disturbance wave hits the bystanders that they
Speaker 1: experience the boom. And at that distance it is probably
Speaker 1: a really bad thing to experience. It would probably mess
Speaker 1: up your internal organs. To be honest, it's not that
Speaker 1: pleasant when a supersonic aircraft passes thousands of feet overhead,
Speaker 1: If it's low enough, it could possibly even cause a
Speaker 1: disturbance strong enough to break windows. And that's another important
Speaker 1: thing to remember. The sonic boom actually travels with the object,
Speaker 1: it doesn't just happen when the object breaks the sound barrier.
Speaker 1: Those disturbance waves trail behind the aircraft, creating a sonic
Speaker 1: boom that follows along with the jet. So if a
Speaker 1: supersonic aircraft travels directly over a populated area and maintains
Speaker 1: that high speed, people in one town will hear the
Speaker 1: boom shortly after the aircraft passes overhead. People three towns
Speaker 1: over will hear a boom as the aircraft passes them,
Speaker 1: So it's a traveling boom. More importantly, for this story,
Speaker 1: Yeager made it back to the ground safely and was
Speaker 1: no worse coming out of the experience than he was
Speaker 1: going into it, though I imagine it did aggravate his
Speaker 1: broken ribs. And Yeager's flight opened up interesting possibilities. Traveling
Speaker 1: at such high speeds could allow for much shorter flights
Speaker 1: across great distances. I'll explain why that was important in
Speaker 1: just a second, but first, let's take a quick break.
Speaker 1: So traveling at high speeds allows for shorter flights across
Speaker 1: great distances. The only problem was companies would have to
Speaker 1: figure out how to design and build a passenger aircraft
Speaker 1: capable of supersonic flight to take advantage of it. Numerous
Speaker 1: airlines and aviation companies began to consider the possibilities, and
Speaker 1: some of them started to spit ball some design ideas.
Speaker 1: It would take a while because this was super early days.
Speaker 1: Most of the early supersonic jets were really just men
Speaker 1: as research vehicles. A few were military vehicles, and none
Speaker 1: of them could travel at those high speeds for very long,
Speaker 1: nor could they really you the typical types of maneuvers
Speaker 1: that a passenger jet would have to do routinely. So
Speaker 1: what was needed was a commercial supersonic transport aircraft, or
Speaker 1: an S s T as they were known. On November
Speaker 1: twenty nine, nineteen sixty two, the governments of Britain and
Speaker 1: France came together to propose a joint effort to develop
Speaker 1: such a passenger aircraft. It was a Concord Agreement, which
Speaker 1: is where the name for the aircraft came from. The
Speaker 1: treaty the two governments signed meant that both countries would
Speaker 1: share the costs and the risks of such an endeavor,
Speaker 1: and they weren't the only countries interested in developing an
Speaker 1: s s T. Both the then Soviet Union and the
Speaker 1: United States were exploring the possibility as well. Boeing even
Speaker 1: received a contract in the United States to build a prototype,
Speaker 1: but that program ended in nineteen seventy one after a
Speaker 1: federal analysis concluded that the program would be too expensive
Speaker 1: with two uncertain to payoff to justify funding it, so
Speaker 1: that was put on the shelf. The Soviets actually saw
Speaker 1: their program through to completion. They built an s ST
Speaker 1: called the Tupa Love or the TU one four. It
Speaker 1: got the nickname the Concorde SKI, somewhat uh narrow minded
Speaker 1: nickname for a supersonic passenger jet, but I find it
Speaker 1: particularly amusing because the TU one four had its first
Speaker 1: flight a couple of months before the Concorde would in
Speaker 1: nineteen sixty nine, and they even had their first supersonic
Speaker 1: flight before the Concorde did. However, the Concorde would beat
Speaker 1: the t U one when it came to entering into
Speaker 1: commercial service to actually carrying passengers, and the Soviets would
Speaker 1: end up shutting their passenger program down after less than
Speaker 1: a year of being in service. But more on that later.
Speaker 1: Let's get back to Concorde. The French and British governments
Speaker 1: contracted various companies to develop the components for the aircraft.
Speaker 1: One of the two companies responsible for developing the body
Speaker 1: of the aircraft was the British Aircraft Corporation or b
Speaker 1: a C. That was a pretty complicated story in itself.
Speaker 1: That company was the result of the merger of several
Speaker 1: other British aviation companies, and it could merit its own podcast.
Speaker 1: B a C itself would later end up merging with
Speaker 1: other aviation companies, and these days we know it as
Speaker 1: British Aerospace. The other company responsible for developing the aircraft
Speaker 1: body was France's Aerospecial, which I'm sure I'm butchering. There's
Speaker 1: going to be a lot of butchering of French names
Speaker 1: in this episode. I make apologies for it, but I
Speaker 1: am an ignorant American type anyway. Aerospace cl was a
Speaker 1: state owned aerospace manufacturer, and it also has a any
Speaker 1: complicated history. The state owned companies are a very different
Speaker 1: thing from the types of companies we tend to think about.
Speaker 1: In the United States, Aerospacel would have its own complicated
Speaker 1: corporate journey, and most of what was Aerospacel is now
Speaker 1: part of the company. Airbus engine design fell to France's
Speaker 1: I really apologize for this Society Nacionale dettude at the
Speaker 1: construction de Motirosa or SNECKMA s n e c M A.
Speaker 1: SNECKMA is way more fun for me to say. And
Speaker 1: it also fell to a British company, Rolls Royce. Yep,
Speaker 1: Rolls Royce wasn't just a super duper fancy car manufacturer.
Speaker 1: They make jet engines too, if you weren't familiar with that. Now,
Speaker 1: I'll talk about the physical design of the aircraft first.
Speaker 1: I'll get to the engines later. Remember when I said
Speaker 1: an object moving about as fast as sound owned uh
Speaker 1: would be catching up to the sound waves that it's
Speaker 1: actually producing. And that the object moves faster than sound,
Speaker 1: it's breaking through the sound barrier. And that sound moving
Speaker 1: through the air is really all about fluctuations and air pressure.
Speaker 1: That means you have to design an aircraft that can
Speaker 1: punch through a wall of air pressure to break through
Speaker 1: that barrier. For that reason, the Concord's physical design featured
Speaker 1: a body shaped sort of like a needle. A Concorde
Speaker 1: jets fuselage measured nine and a half feet wide or
Speaker 1: two point seven meters. A seven forty seven, by comparison,
Speaker 1: would have measured a twenty feet or six point one
Speaker 1: meters wide, But the Concord's length of two d two
Speaker 1: feet or sixty one point seven ms was nearly as
Speaker 1: long as a seven forty seven, so it's much more
Speaker 1: narrow but almost as long as this other aircraft. The
Speaker 1: Concorde could hold a total of one passengers, with two
Speaker 1: seats on either side of a sin troll aisle, so
Speaker 1: you have rows of four, two and two and twenty
Speaker 1: five of them. You would never have a middle seat,
Speaker 1: which is pretty awesome. You would only ever have a
Speaker 1: window seat or an aisle seat. The typical flight crew
Speaker 1: on a Concorde flight included a pilot, a co pilot,
Speaker 1: a flight engineer, and six cabin crew members, so a
Speaker 1: full Concord jet with a typical crew would have on
Speaker 1: six people on board. Some flights actually had more crew
Speaker 1: members on it than the typical six, so that wasn't
Speaker 1: always the case. Also, the experience aboard of Concorde was
Speaker 1: pretty darn posh. We're talking caviar and champagne. I'm guessing
Speaker 1: that's where Robin Leach had all those dreams. And if
Speaker 1: you don't know who I'm talking about, you need to
Speaker 1: go over to YouTube and search for lifestyles of the
Speaker 1: rich and famous. Anyway, back to the physical design of
Speaker 1: this aircraft, the nose of the Concorde was really interesting.
Speaker 1: It was actually move a bullet, wasn't fixed or bolted
Speaker 1: into place in the way that you would think of
Speaker 1: a normal aircraft. There was a reason for this. It
Speaker 1: was to give pilots more visibility on the ground. Whenever
Speaker 1: they were regg getting raid for takeoff or when they
Speaker 1: were approaching for landing, the nose could actually be tilted
Speaker 1: down thirteen degrees and that would provide the pilot's more visibility. Otherwise,
Speaker 1: the nose was up so high that they couldn't really
Speaker 1: see what was kind of in front of them on
Speaker 1: the ground. Once the air pilots could engage the controls
Speaker 1: and the nose would tilt up to its in flight position.
Speaker 1: In addition, the Concorde had a delta wing design. The
Speaker 1: wing swept back into a triangular shape and joined to
Speaker 1: the fuselage of the aircraft all down the length of
Speaker 1: the wing, as opposed to say, the wings of a
Speaker 1: jet like the seven seven, which has rectangular wings that
Speaker 1: stretch out from the sides of the fuselage. It doesn't
Speaker 1: go all the way back the body of the plane.
Speaker 1: It's called a delta wing because the shape resembles the
Speaker 1: Greek upper case letter delta, which is a triangle. The
Speaker 1: design allows for a really strong wing that can stand
Speaker 1: up to the rigors of high speed, subsonic and supersonic flight.
Speaker 1: It's a design used in lots of military jets, and
Speaker 1: the Space Shuttle program in the United States used a
Speaker 1: delta wing design as a basis for their orbiter. The
Speaker 1: design reduces drag at supersonic speeds while still allowing for
Speaker 1: sufficient lift for takeoff and landing at subsonic speeds, and
Speaker 1: it also provides stability. It eliminates the necessity for horizontal
Speaker 1: stabilizers on the aircraft's tail. That design also meant the
Speaker 1: Concorde had a steeper angle of attack for takeoffs and landings,
Speaker 1: so I imagined flying on one of these was a
Speaker 1: bit of a thrilling experience. If you've ever had to
Speaker 1: fly in or out of an airport that had specific
Speaker 1: ordinances that required a steeper than normal flight path. You
Speaker 1: might have a hint of what it was like to
Speaker 1: be on a concord. Now, I'm going to talk about
Speaker 1: the engines in just a second, but I figured it
Speaker 1: would be a good time to give you an idea
Speaker 1: of what takeoff was like on a concorde. The jet
Speaker 1: would accelerate from zero to two hundred twenty five miles
Speaker 1: per hour or three hundred sixty two kilometers per hour
Speaker 1: in just three seconds, so that acceleration would push you
Speaker 1: back into your seat all by itself, never mind the
Speaker 1: fact that you would soon be climbing at a steeper
Speaker 1: than normal angle. Another thing engineers had to take into
Speaker 1: consideration was the wear and tear that air pressure, friction,
Speaker 1: and heat would have on the concorde. Traveling at supersonic
Speaker 1: speeds meant that the aircraft body would heat up considerably
Speaker 1: as high pressure air moved against the plane's surface. Measurements
Speaker 1: showed that the concord's surface temperature during supersonic flight would
Speaker 1: range from one seven degrees celsius or two hundred sixty
Speaker 1: one fahrenheit at the nose of the plane down to
Speaker 1: ninety one degrees celsius or one six degrees fahrenheit at
Speaker 1: the tail. All that heat was bound to have an
Speaker 1: effect on the lane. In fact, the air frame of
Speaker 1: the Concorde would expand seven inches or seventeen point eight
Speaker 1: centimeters during flight, so you can imagine that repeated flights
Speaker 1: could cause some serious structural problems if the plane is
Speaker 1: effectively changing shape by the magnitude of seven inches. For
Speaker 1: that reason, engineers used a special aluminum or aluminium if
Speaker 1: you prefer alloy, and that was known to be heat
Speaker 1: tolerant as well as lightweight, so it made a good
Speaker 1: material for the airframe. Another way engineers chose to deal
Speaker 1: with that heat was to coat the Concorde in highly
Speaker 1: reflective white paint. It was paint designed to be about
Speaker 1: twice as reflective as what you would find on other
Speaker 1: jets at the time. So what about the engines. Well,
Speaker 1: the Rolls Royce SNECMA Olympus five nine three turbojet engines
Speaker 1: could each create eighteen point seven tons of thrust or
Speaker 1: one eight kilo Newton's and each Concorde had four of
Speaker 1: those engines. Collectively, they burned six thousand, seven hundred seventy
Speaker 1: one gallons or twenty five thousand, six hundred twenty nine
Speaker 1: liters of jet fuel per hour, and there were seventeen
Speaker 1: of them on each concord. Those seventeen tanks could collectively
Speaker 1: hold thirty one thousand, five hundred sixty nine gallons or
Speaker 1: one hundred nineteen thousand, five hundred liters of kerosene jet fuel,
Speaker 1: and some of that fuel wasn't used to make the
Speaker 1: jet go. It was actually used to help balance the
Speaker 1: plane itself. The Concorde had three auxiliary fuel tanks called
Speaker 1: trim fuel tanks. There were two in the front and
Speaker 1: one in the tail, and their purpose was to help
Speaker 1: with flight stability and orientation. When the Concorde would reach
Speaker 1: supersonic speeds, its aerodynamic center would shift backward. That caused
Speaker 1: the plane's nose to lower and point downward. To counter
Speaker 1: that tendency, the Concorde could pump fuel backward into the
Speaker 1: trim tank near the tail. The redistribution of fuel would
Speaker 1: make the Concord's center of gravity match its center of lift,
Speaker 1: and the plane would level out. As the plane left
Speaker 1: supersonic speeds, the system would pump fuel into the forward
Speaker 1: fuel trim tanks to essentially do the same process, but
Speaker 1: in reverse because the jets nose would start to point upwards,
Speaker 1: so they needed to counteract that action. These engines attached
Speaker 1: directly to the underside of the concord's wings, rather than
Speaker 1: using engine struts as is more typical in jet plane designs.
Speaker 1: So why deviate from the standard, Well, engineers concluded that
Speaker 1: engine struts wouldn't be able to stand up to the
Speaker 1: stresses of supersonic travel, so the jets need to be
Speaker 1: directly integrated into the wing design, and it was collectively
Speaker 1: decided that a supersonic jet having an engine fly off
Speaker 1: due to turbulence would be what is called a bad
Speaker 1: thing in aviation. The jet engines used a technology commonly
Speaker 1: found on military superscient jets after burners, So to understand
Speaker 1: how those work, it helps first to have a refresher
Speaker 1: on how jet engines work in general. So think of
Speaker 1: a jet engine as a machine that takes incoming cold air,
Speaker 1: heats it up tremendously, and jects it as outgoing hot
Speaker 1: air at a high velocity, and this creates forward thrust.
Speaker 1: Because every action has an equal but opposite reaction, So
Speaker 1: inside a jet engine are the following components you have
Speaker 1: a compressor, a combustion chamber, and a turbine. And if
Speaker 1: you were to have like a cross section of a
Speaker 1: jet engine and you're looking at it from front to back,
Speaker 1: that's the order you would see them in compressor, combustion chamber, turbine.
Speaker 1: Now I'm going to talk about the compressor and the
Speaker 1: turbine parts first, because the compressor's operation depends upon the turbine.
Speaker 1: So the compressor is essentially a series of bladed fans. So,
Speaker 1: for the purposes of an analogy, imagine you have ten
Speaker 1: fans that you've taken out of box fans, you know,
Speaker 1: the kind of fans that you would put in a
Speaker 1: in a window. So you've taken ten of those, and
Speaker 1: you've taken the fan blades out of all ten, and
Speaker 1: you've mounted them all on the same pole. But the
Speaker 1: fans that are in the odd numbered positions, so one, three, five, seven,
Speaker 1: and nine, those can freely rotate around the pole. But
Speaker 1: the even numbered fans have been bolted in place. The
Speaker 1: poll is going to remain stationary. The fans that are
Speaker 1: bolted to it will remain stationary. The rotating ones can
Speaker 1: freely move, and somehow magically, you've created a method to
Speaker 1: make them rotate in the direction you need them to
Speaker 1: go in. I don't care how you do it. Maybe
Speaker 1: you've got a Wand so the rotating fans are rotors
Speaker 1: and the fixed fans are statters. Now, imagine you've en
Speaker 1: cased this entire thing in a tube, and as air
Speaker 1: moves into the tube, you have these turning fans, and
Speaker 1: it pulls the air in and compresses the air as well.
Speaker 1: As the air continues to move past, both the rotors
Speaker 1: and the statters and the rotating fans add more pressure
Speaker 1: to the air. And as the air pressure goes up,
Speaker 1: so does the air temperature. Now that's what's going on
Speaker 1: in a jet engine, but in a jet engine, it's
Speaker 1: happening on steroids and the turbine on the other end
Speaker 1: of this system is what is providing the rotational force
Speaker 1: to move the compressor rotors. So in between those two
Speaker 1: components is the combustion chamber, and that's where jet fuel
Speaker 1: gets injected and then burned. It's ignited, and that heats
Speaker 1: the air that's passing through the jet engine. The air
Speaker 1: is coming from the compressor through the combustion chamber, it's
Speaker 1: combining with jet fuel. It's getting ignited. That heats the
Speaker 1: air up into super hot gases that then pass through
Speaker 1: the backside of the combustion chamber. The heat causes air
Speaker 1: to expand, and by shaping the end of the jet
Speaker 1: engine so that air can only really escape from a
Speaker 1: relatively narrow exhaust port, you end up getting a lot
Speaker 1: of thrust. You've increased the speed at which the gas
Speaker 1: is going to come out the back of the jet,
Speaker 1: and that increases the thrust on the jet, or a
Speaker 1: forward thrust movement. The hot air has to leave and
Speaker 1: you've only provided the one exit, so it moves to
Speaker 1: that high speed and you get that forward thrust on
Speaker 1: the way out. The hot air actually turns that turbine,
Speaker 1: so the hot air is passing through the turbine that's
Speaker 1: creating the rotational force, and it transmits the rotational force
Speaker 1: to the compressor blades, the rotors specifically. So what does
Speaker 1: an afterburner do because that's just a regular jet engine. Well,
Speaker 1: there's a hint in the name. After Burners are components
Speaker 1: used in some jets to provide additional thrust, and the
Speaker 1: way they do that is to heat up that exhaust
Speaker 1: gas to even higher temperatures in order to increase the
Speaker 1: velocity of the gas as its exhaust staying out the
Speaker 1: back of the jet engine, so that provides more forward thrust.
Speaker 1: You've just increased the velocity of the escaping gas. So
Speaker 1: why not just do that in a normal jet engine?
Speaker 1: Why not just soup up the combustion chamber so that
Speaker 1: it heats up the air even more. Well. The parts
Speaker 1: of a jet engine can only withstand so much heat,
Speaker 1: and by parts, i'm mainly talking about that turbine that's
Speaker 1: used to provide the rotational force to the compressor rotors.
Speaker 1: If you heat it up too much, then it's going
Speaker 1: to destroy that turbine and you're going to have a
Speaker 1: complete engine failure. So, and after burner comes after the
Speaker 1: turbine of the jet engine, you get this hot gas.
Speaker 1: It's just passed through the turbine, imparting some rotational force
Speaker 1: to it, and that exhausted gas, which still has some
Speaker 1: air that wasn't all consumed in combustion, combines with a
Speaker 1: little more jet fuel and goes into another after burner
Speaker 1: combustion chamber, and that's further back in the overall engine.
Speaker 1: That increases the temperature of the exiting gases significantly, which
Speaker 1: increases the velocity of the escaping exhaust and boosts the thrust.
Speaker 1: Inside the afterburner chamber, you would find some sort of
Speaker 1: lining that would actually help protect the jet engine casing
Speaker 1: from all that heat. The lining would be extremely heat resistant.
Speaker 1: Typically there beholes in it as well to help deal
Speaker 1: with some of the noise coming from this combustion chamber.
Speaker 1: Otherwise that noise would become uh this very strong vibrational
Speaker 1: energy that could cause structural damage to the actual jet,
Speaker 1: because that's how much how much energy we're talking about here,
Speaker 1: It's it's a huge amount. And then you would have
Speaker 1: the end of the chamber, which would be a converging
Speaker 1: and then diverging nozzle. So the chamber converges in tilts inward.
Speaker 1: It creates that narrow path for the gases to flow through,
Speaker 1: and then the nozzle diverges or widens out to allow
Speaker 1: them to disperse into the atmosphere. And ideally the size
Speaker 1: the the width of that divergence is such that the
Speaker 1: pressure of the exhaust coming out equals the air pressure
Speaker 1: that the aircraft is moving through, and you have a
Speaker 1: very efficient system. Otherwise you have some other factors you
Speaker 1: have to take into consideration, but it gets way too complicated,
Speaker 1: so we're not going to go into that for this discussion.
Speaker 1: So how about some performance stats. We talked about what's
Speaker 1: going on inside the engine, but what does that actually
Speaker 1: translate to. Well, the Concord's top cruising speed was one thousand,
Speaker 1: three hundred fifty four miles per hour, which is two thousand,
Speaker 1: one seventy nine kilometers per hour. It's also known as
Speaker 1: mock two point zero four. They'll keep in mind the
Speaker 1: speed of sound depends upon lots of stuff. Sound actually
Speaker 1: travels slower at high altitudes than it does at sea
Speaker 1: level under typical atmospheric conditions, but again we won't go
Speaker 1: into that. The Concorde also cruised along at a much
Speaker 1: higher altitude than other jets did, typically at around sixty
Speaker 1: thousand feet or eighteen thousand, three hundred. Contrast that to
Speaker 1: the good old Boeing seven forty seven, which was a
Speaker 1: standard aircraft in United States service for a really long time.
Speaker 1: It would cruise at a speed of around five hundred
Speaker 1: sixty miles per hour or nine hundred one kilometers per hour,
Speaker 1: and it would do so in an altitude of around
Speaker 1: thirty five thousand feet or ten thousand, six hundred seventy five,
Speaker 1: so the Concorde would travel in an altitude nearly twice
Speaker 1: as high as A seven seven and more than twice
Speaker 1: as fast, almost three times as fast s seven forty seven.
Speaker 1: While the first prototype Concord to take flight did so
Speaker 1: in March nineteen and the first one to go supersonic
Speaker 1: did so in the fall of that year, there was
Speaker 1: still a lot more testing to do before people could
Speaker 1: buy a ticket and travel on one of these. The
Speaker 1: first transatlantic test flight between London and New York happened
Speaker 1: on September ninety three, and the first passenger service would
Speaker 1: follow three years later on January one, nineteen seventy six,
Speaker 1: and initially you could fly between London and ball Rain,
Speaker 1: or Paris and Rio de Janeiro. A bit later service
Speaker 1: extended from both London and Paris to Washington, d C.
Speaker 1: And New York City, and a lot miller was to follow.
Speaker 1: But let's take a quick break, so you could travel
Speaker 1: from London or Paris to DC or New York City.
Speaker 1: And then there were a few other routes that would
Speaker 1: be added seasonally, but they were all limited because the
Speaker 1: noise the plane created as it flew overhead meant that
Speaker 1: the airlines had to be really selective of their routes
Speaker 1: to avoid causing too much of a disturbance overpopulated areas.
Speaker 1: They tried to limit their flights over the water, not
Speaker 1: over the land, so there are only so many places
Speaker 1: you could go, and no one on land one of
Speaker 1: their days to be punctuated by constant sonic booms. So
Speaker 1: the concords blistering speed did help for those transatlantic flights.
Speaker 1: It meant you could hop on the concorde and at
Speaker 1: a flight from London to New York and you could
Speaker 1: get there in about three and a half hours if
Speaker 1: you factor in another half hour for all the taxiing
Speaker 1: and other procedures. It meant that you would be landing
Speaker 1: in New York about an hour before you left London.
Speaker 1: Because London is in the time zone we designate as
Speaker 1: being Coordinated Universal Time or u t C what we
Speaker 1: used to call Greenwich meantime, New York is at UTC
Speaker 1: minus five, meaning it's five hours behind London on standard time.
Speaker 1: So if you take off from London at noon and
Speaker 1: you land in New York three and a half hours later,
Speaker 1: and then you have all the taxing and stuff. You'd
Speaker 1: be stepping off the plane with a local time in
Speaker 1: New York being eleven am, so from the perspective of
Speaker 1: your watch, you've actually landed an hour before you took off.
Speaker 1: Of course, back in London it would be four pm,
Speaker 1: but that's not nearly as much fun when you want
Speaker 1: to walk around and pretend that you're a time traveler. Now,
Speaker 1: obviously that only works if you're traveling west. If you're
Speaker 1: going east, you have to add time zones to your
Speaker 1: travel time. But still the flight time itself would be
Speaker 1: back significantly. And perhaps the most important thing is that
Speaker 1: as a passenger, you're not stuck on a concorde as
Speaker 1: long as you would be on another passenger jet. You
Speaker 1: get to spend more time at home or at your
Speaker 1: destination and less time traveling, and that's a pretty cool experience.
Speaker 1: It was also an expensive experience. If we had just
Speaker 1: for inflation, a round trip ticket between London and New
Speaker 1: York City would set you back about twenty thousand dollars.
Speaker 1: But the Concord's reputation is tied to more than impressive
Speaker 1: speed performance. It's also tied to tragedy engineering problems, political
Speaker 1: and social hurdles, and economic factors that collectively brought the
Speaker 1: program to an end. In the early two thousand's. The
Speaker 1: Concorde aircraft had a reputation for being mechanically difficult. Usually
Speaker 1: the mechanical failures were non critical, but there was one
Speaker 1: terrible instance where that was not the case. On July twenty,
Speaker 1: two thousand, a flight leaving Paris for New York crashed
Speaker 1: just after it took off. All aboard the plane died
Speaker 1: in that crash, as did a few people on the ground.
Speaker 1: An investigation concluded that there had been a loose strip
Speaker 1: of metal on the runway, and that when the Concorde
Speaker 1: passed over the metal, it tore into one of the
Speaker 1: jets tires. The tire blew out, and pieces of the
Speaker 1: tire got pulled into either the engine or the fuel tank,
Speaker 1: or both, and caused a fire on the port side engine.
Speaker 1: The aircraft then crashed into a hotel. The accident prompted
Speaker 1: both the UK and France to ground their Concord planes. Now,
Speaker 1: despite the high price for a ticket, the venture was
Speaker 1: losing money. Fuel and maintenance costs for the aircraft were
Speaker 1: sky high. Pun intended the oil crisis of the early
Speaker 1: seventies hurt the Concorde before it even entered into passenger service,
Speaker 1: with several airlines canceling orders for the aircraft and so
Speaker 1: operating the Concord fleets was largely a money losing proposition. Ultimately,
Speaker 1: it became pretty clear that the service was too risky
Speaker 1: and not economically viable. On top of that, there was
Speaker 1: the environmental impact created by burning so much jet fuel
Speaker 1: on every flight. However, I should point out typically the
Speaker 1: Concorde would burn less fuel than other jets because the
Speaker 1: flight time was so much shorter on a Concorde, so yes,
Speaker 1: it burned more fuel per hour, but its spent fewer
Speaker 1: hours in the air. There was also concern that at
Speaker 1: the high altitude that that exhaust could end up having
Speaker 1: a negative impact on the ozone layer. So there were
Speaker 1: a lot of environmental concerns related to the Concord. In addition,
Speaker 1: because the aircraft couldn't fly over land without causing a ruckus,
Speaker 1: Asia was off limits. The jets didn't have the fuel
Speaker 1: capacity to travel west from Europe and get all around
Speaker 1: the world to get to Asia, and business travel was
Speaker 1: shifting more towards Asia as time was going on, which
Speaker 1: wasn't a factor when they were first planning the Concorde.
Speaker 1: The Concorde seemed like it was too high a cost
Speaker 1: to cut down on travel time by a few hours
Speaker 1: across the atlant The convenience did not justify the expense,
Speaker 1: and it was just not making money, and that high
Speaker 1: cost had been a problem from the very beginning. Just
Speaker 1: developing the Concorde went way over budget. According to Ross Aimer,
Speaker 1: the CEO of Arrow Consulting Experts quote, cost overruns were tremendous,
Speaker 1: going from seventy million pounds to one point three billion
Speaker 1: pounds end quote. Both Air France and British Airways would
Speaker 1: cease Concord flights in two thousand three. Out of the
Speaker 1: twenty Concord jets ever built, only fourteen ever served as
Speaker 1: passenger aircraft, seven in the UK, seven in France. After
Speaker 1: being grounded, some of the planes were disassembled, while others
Speaker 1: were put into museums. But what about the other supersonic
Speaker 1: transport aircraft that I mentioned earlier, the Tupolev or the
Speaker 1: Concord Ski. Well, it took flight a couple of months
Speaker 1: before the Concord's first test flight, and it achieved supersonic flight,
Speaker 1: first being the Concord by four months in the summer
Speaker 1: of nineteen sixty nine, but the actual passenger service in
Speaker 1: the Soviet Union didn't start until after Concorde entered service.
Speaker 1: So what happened In nineteen seventy three a t U
Speaker 1: crashed during the Paris Air Show, possibly probably due to
Speaker 1: pilot error. While going through some complicated air maneuvers, the
Speaker 1: aircraft broke apart and fourteen people died, six on the
Speaker 1: plane and eight on the ground. The highly publicized accident
Speaker 1: put the passenger program on ice in the USSR and
Speaker 1: delayed its roll out until November one, nineteen. It was
Speaker 1: reportedly a much noisier experience. Like the Concorde, the t
Speaker 1: U one four could only achieve supersonic flight through after burners,
Speaker 1: but they apparently used military after burners and they was
Speaker 1: produced a lot of noise along with all that thrust.
Speaker 1: So the TUO design, as I understand it, didn't mitigate
Speaker 1: that noise very well, and so passengers would endure a loud, vibraty,
Speaker 1: shaky flight and that didn't sound very pleasant. The only
Speaker 1: serve US they had was between Moscow and Kazakhstan, and
Speaker 1: flights were rarely full. The service completed fifty five passenger
Speaker 1: flights before being canceled. It was already destined to be
Speaker 1: mothballed when another fatal accident happened. On May twenty three,
Speaker 1: nineteen seventy eight, a t U one caught on fire
Speaker 1: near Moscow and made an emergency landing. The two fatalities
Speaker 1: were flight engineers. The unreliability of the aircraft and the
Speaker 1: absence of economic incentives to continue running passenger flights meant
Speaker 1: the t U one forty four would transition into running
Speaker 1: mail carrying jobs and serving as a test bed for
Speaker 1: aerospace operations. Only seventeen t U one forty four were
Speaker 1: ever built, including the prototypes, and from what I've seen,
Speaker 1: the last flight of a t U one forty four
Speaker 1: happened in nineteen Several companies and organizations are working to
Speaker 1: build a new generation of super fast planes. We're not
Speaker 1: talking supersonic necessarily, we might be talking hypersonic. These would
Speaker 1: be aircraft capable of traveling at insane speeds like mock
Speaker 1: five or faster. NASA tested such an aircraft back on
Speaker 1: November six, two thousand four, a year after Concorde had
Speaker 1: shut down. The aircraft had the designation X forty three A,
Speaker 1: and the X tells you it's an experimental aircraft. It's
Speaker 1: set a world speed record for a jet powered aircraft
Speaker 1: at mock nine point six. That's nearly seven thousand miles
Speaker 1: per hour or eleven thousand, two hundred sixty five kilometers
Speaker 1: per hour. Now that wasn't an ss T. The X
Speaker 1: four three A was an unmanned test vehicle. It's meant
Speaker 1: as a proof of concept, but it is just one
Speaker 1: example of how NASA continues to research hypersonic vehicles. Companies
Speaker 1: like Boeing have shown off concepts of hypersonic passenger planes.
Speaker 1: At the a I a A Aviation Forum in two
Speaker 1: thousand eighteen, Boeing unveiled a concept of a passenger jet
Speaker 1: that would, in theory, hit speeds of mock five. Instead
Speaker 1: of a conventional jet engine, the hypersonic aircraft would use
Speaker 1: a ramjet once it hit high speeds. That's because the
Speaker 1: speed it would travel out would cause a turbine to
Speaker 1: spend so fast it would break apart. Ram jets use
Speaker 1: the forward motion of the aircraft itself to compress the
Speaker 1: air into an afterburner chamber, so the hypersonic jet would
Speaker 1: likely have turbojet engines for the slower speeds, the subsonic
Speaker 1: and maybe supersonic speeds. Then a valve would allow air
Speaker 1: to bypass the turbo fans and go straight to the ramjets. However,
Speaker 1: I wouldn't get too excited because most estimations put the
Speaker 1: launch date of such a service at twenty to thirty
Speaker 1: years in the future, So if you need to get
Speaker 1: to wherever you're going faster than that, you could probably
Speaker 1: just walk there. In addition to figuring out how to
Speaker 1: fly really fast, engineers are working on how to reduce
Speaker 1: the profile of aircraft so that they can in turn
Speaker 1: reduce the sonic boom effect, making the aircraft more practical
Speaker 1: over a larger numb of flight paths and not just
Speaker 1: over the ocean. Back at NASA, engineers have been experimenting
Speaker 1: with jet body designs and have proposed an aircraft called
Speaker 1: the X fifty nine QUEST. The s T is not
Speaker 1: an ST in quest. It is an uppercase SST for
Speaker 1: supersonic transport, which is cute. Lockeed Martin is building that jet.
Speaker 1: If it works as the engineers intended, this test vehicle
Speaker 1: should be able to travel at supersonic speeds, not hypersonic,
Speaker 1: but supersonic speeds without creating as explosive a sonic boom.
Speaker 1: The goal is to make a more modest boom. In fact,
Speaker 1: the agency calls it low boom. No boom isn't really
Speaker 1: an option because you know physics. And besides NASA, there
Speaker 1: are other companies like Virgin Galactic, which is partnering with
Speaker 1: of course Boom Technology to build a quiet supersonic jet,
Speaker 1: and Spike Aerospace. Yet another company is also in the
Speaker 1: race for quiet super fast flight. The company closest might
Speaker 1: be Arian Corporation. With support from Airbus, it is producing
Speaker 1: a supersonic business jet called the A S two and
Speaker 1: that should have a top speed of around mock one
Speaker 1: point five, so not as fast as the Concorde, but
Speaker 1: still pretty darn fast. However, it's also a low capacity jet.
Speaker 1: It has room for twelve passengers per plane, so I'm
Speaker 1: guessing that's gonna be a pretty tough ticket to score.
Speaker 1: The question remains whether or not these types of jets
Speaker 1: will be commercially viable with the cost of operating them.
Speaker 1: Is it ever going to mean that the operational costs
Speaker 1: will be low enough so that companies running supersonic flights
Speaker 1: can make a profit without setting stratospheric and that's also
Speaker 1: upon ticket prices. Or are you going to need to
Speaker 1: take out a second mortgage if you ever want to
Speaker 1: get a plane ticket on one of these things. My
Speaker 1: guess is that supersonic and definitely hypersonic travel will be
Speaker 1: luxury options. There will be an option that really only
Speaker 1: a select few will be able to take advantage of
Speaker 1: the truly wealthy, uh and connected, unless somehow the economies
Speaker 1: of scale takeover and make things cheaper. I doubt you're
Speaker 1: going to find your standard options whenever you log into
Speaker 1: your airline to include supersonic flights at budget prices. But
Speaker 1: I could be wrong. I hope I am. It would
Speaker 1: be awesome if that were the case. It would be
Speaker 1: great to get to places faster, but I suspect that,
Speaker 1: at least in the near future, that's not going to
Speaker 1: be the case. But that wraps up this discussion of
Speaker 1: the Concorde. Happy birthday, Concorde, Welcome to the Big five.
Speaker 1: Oh um, I guess you're not up too much because
Speaker 1: you retired back in two thousand three. Retirement sounds nice.
Speaker 1: Send me a postcard, let me know how that's going
Speaker 1: for you. If you guys have suggestions for future episodes
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