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: I Heart Radio and I love all things tech. But again,
Speaker 1: this is another one of those episodes where I have
Speaker 1: to couch that so not that long ago, I did
Speaker 1: a series of episodes about the company Bowing and its history,
Speaker 1: which once again is in the news as I record
Speaker 1: this episode. So the week I'm recording this, which is
Speaker 1: the very end of October, actually technically today is November one.
Speaker 1: The CEO of Boeing just appeared before Congress to answer
Speaker 1: questions about the tragedies involving two seven thirty seven Max
Speaker 1: aircraft crashes. Politicians asked some very pointed questions to find
Speaker 1: out when people at Boeing became aware of problems with
Speaker 1: the aircraft and how much they knew, as well as
Speaker 1: other details. So in this episode, I want to explore
Speaker 1: exactly what went wrong and why. And while you could
Speaker 1: summarize the story by saying a sensor and some software malfunctioned,
Speaker 1: that's not really a full understanding of exactly what went
Speaker 1: wrong and why it went wrong. So let's start with
Speaker 1: the seven thirty seven Max in general, and the seven
Speaker 1: thirty seven Max is history really only dates back to
Speaker 1: July two thousand eleven. That's when Boeing learned that it's competitor,
Speaker 1: air Bus, had made a deal with American Airlines to
Speaker 1: sell two hundred A three twenty neo aircraft and the
Speaker 1: eight three twenty family of aircraft first debuted in nineteen
Speaker 1: eight six. They're intended to serve as short to medium
Speaker 1: range aircraft. They are narrow body aircraft, which means they
Speaker 1: have a cabin that measures no more than thirteen ft
Speaker 1: or four meters wide, and they have a single aisle
Speaker 1: going down the length of the cabin with seats on
Speaker 1: either side. In other words, these aircraft sir the same
Speaker 1: function as something like the seven thirty seven does. So
Speaker 1: it might be a good idea to do a quick
Speaker 1: rundown on the different sizes of aircraft and what they're
Speaker 1: intended functions are, and to understand why we even have
Speaker 1: these different sizes of aircraft. It helps to understand the
Speaker 1: history of the development of airports and airlines in general.
Speaker 1: I find that it could be easy to forget that
Speaker 1: the systems we have in place today evolved over time
Speaker 1: out of necessity. But I also know that's not the
Speaker 1: focus of our episodes, So we're gonna be super general.
Speaker 1: I'm not going to spend an enormous amount of time
Speaker 1: on this, So the Right Brothers, really, I'm not going
Speaker 1: to spend a whole lot time on this. But they
Speaker 1: developed the first real airplane in the United States in
Speaker 1: the early twentieth century by n In the United States,
Speaker 1: the government had passed the Air Mail Act that gave
Speaker 1: the Postmaster General the authority to work with private airlines
Speaker 1: flying between certain routes the ability to carry mail. This
Speaker 1: was sort of laying the groundwork for the modern airline.
Speaker 1: The government followed that up with the Air Commerce Act,
Speaker 1: which gave powers to the Secretary of Commerce to create
Speaker 1: the rules and regulations that would apply to commercial aircraft.
Speaker 1: That included requirements to license pilots, to certify specific aircraft
Speaker 1: as being safe for commercial operation, to establish air routes,
Speaker 1: and to create rules for air traffic. Now, many airlines
Speaker 1: in this time were regional. They were operating between a
Speaker 1: handful of cities within a general area of the United States,
Speaker 1: but they gradually were able to grow to provide service
Speaker 1: to more airports further afield. This might require a certain
Speaker 1: number of hops between cities, and it created an incentive
Speaker 1: for aircraft and engine manufacturers to find ways to increase
Speaker 1: the flying range of aircraft to allow for more direct
Speaker 1: service options between distant cities. The US government wasn't done yet, though.
Speaker 1: In ninety eight, Congress past the Civil Aeronautics Act, which
Speaker 1: in turn created these Civil Aeronautics Board or c a B.
Speaker 1: One of the board's responsibilities was to regulate airfare prices
Speaker 1: for passengers. Another was that it could assign specific routes
Speaker 1: to airlines, giving permission for them to operate flights between
Speaker 1: specific cities. The price regulation meant that airlines couldn't really
Speaker 1: compete against each other with battling with lower fares for
Speaker 1: routes between the same cities. A ticket on one airline
Speaker 1: for a trip between let's say New York and Chicago
Speaker 1: would cost pretty much the same as a ticket on
Speaker 1: another airline because of this regulation. So that meant that
Speaker 1: these airlines had to differentiate themselves in service because price
Speaker 1: was going to be the same no matter where you
Speaker 1: were going. Right if you went on one air airline
Speaker 1: versus another you're gonna be paying the same amount, So
Speaker 1: why would you choose one over the other? Had to
Speaker 1: be because of the service. Further, if the Board determined
Speaker 1: then airline was providing sub standard service along a specific route,
Speaker 1: then the board would allow other airlines to operate along
Speaker 1: that same route in order to create the competition needed
Speaker 1: to improve service. So if the Board were to look
Speaker 1: at say t W A and say, your service between
Speaker 1: this city and that city has been reported as being substandard,
Speaker 1: We're now going to allow these three other airlines to
Speaker 1: compete in that space, the idea was that things would improve.
Speaker 1: In nineteen fifty eight, the US government established what we
Speaker 1: now call the Federal Aviation Agency or f a A,
Speaker 1: which oversees airline safety operations. Twenty years later, in nineteen
Speaker 1: seventy eight, the economic climate had changed in the United States.
Speaker 1: Foreign airlines offering service to the US were not bound
Speaker 1: by the price regulations of the Civil Aeronautics Board. American
Speaker 1: airline companies could not compete with the lower airfares posted
Speaker 1: by these foreign companies, and there was a growing resistance
Speaker 1: to regulations in general in the US, so Congress passed
Speaker 1: a deregulation Act than the Civil Aeronautics Board disbanded, The
Speaker 1: price regulations came to an end, and airlines in the
Speaker 1: United States could charge whatever they felt the market could
Speaker 1: bear for any of their airfares. This also allowed new
Speaker 1: airlines to join the market, which had previously been dominated
Speaker 1: by just a few major carriers. The influx of competition
Speaker 1: was a boon to passengers as far as airfare price
Speaker 1: is concerned, but less so when it came to in
Speaker 1: flight experience. More on that in just a moment. But
Speaker 1: it also meant that some of the larger airline carriers
Speaker 1: were struggling to compete. They had grown very large, and
Speaker 1: they depended on a certain amount of revenue that happened
Speaker 1: to have been guaranteed by the regulated prices. So when
Speaker 1: those regulations went away and smaller, more nimble companies began
Speaker 1: operating routes previously commanded by these giant companies, while the
Speaker 1: giants began to wobble a little bit. This was exacerbated
Speaker 1: by an economic recession in the nineteen nineties that saw
Speaker 1: a reduction in air travel, and some of the big
Speaker 1: airlines outright collapsed into bankruptcy, like t w A and
Speaker 1: Pan American. So another recession in two thousand one, and
Speaker 1: then the terrorist attacks on nine eleven further hurt the
Speaker 1: airline industry, which would remain unprofitable for five more years.
Speaker 1: Now since then, you know, since two thousand six, airlines
Speaker 1: have managed to turn things around for the most part. Now,
Speaker 1: the reason all of that was important is that it
Speaker 1: creates the foundation for us to understand why there are
Speaker 1: so many different types of aircraft out there, and why
Speaker 1: conditions and aircraft have changed over time, and this in
Speaker 1: turn informs us as to why Boeing made specific decisions.
Speaker 1: So you may have seen images of air travel in
Speaker 1: the nineteen fifties or nineteen sixties when it looked like
Speaker 1: everyone was dressed in their Sunday best and they're enjoying
Speaker 1: a big, comfy seat with plan D of leg room,
Speaker 1: and they might even be chowing down on an impressive
Speaker 1: looking meal. It's a pretty dramatic contrast to what you
Speaker 1: find on a typical commercial jet today. So let's talk
Speaker 1: about the different types of aircraft classes and what there
Speaker 1: for and why things have changed. So you've got wide
Speaker 1: body aircraft. These are the ones that are meant for
Speaker 1: long range routes, usually such as transatlantic or trans Pacific routes.
Speaker 1: They typically have two aisles running the length of the cabin,
Speaker 1: and the width of the cabin tends to range from
Speaker 1: sixteen to twenty feet or five to six meters. You
Speaker 1: can have up to ten or maybe even eleven seats
Speaker 1: arranged in a single row. In the economy class. They
Speaker 1: really pack them in like sardines and some aircraft. That
Speaker 1: means that with the size of some of these aircraft,
Speaker 1: you can have configurations that can carry more than eight
Speaker 1: hundred passengers, which is mind blowing to me. Most of
Speaker 1: them are more like two fifty four passengers, but there
Speaker 1: are some configurations that have significantly more than that. The
Speaker 1: original wide body aircraft were something like luxury vehicles. They
Speaker 1: were intended to provide a superior experience with more room
Speaker 1: per passenger than you would find on other types of aircraft,
Speaker 1: so they weren't all about packing as many people in
Speaker 1: as possible. But then once the industry underwent deregulation, folks
Speaker 1: that airlines began to figure out that there was another
Speaker 1: tactic they could use. They could cram way more seats
Speaker 1: on those aircraft, actually reducing the space for the average
Speaker 1: traveler and maximizing the number of passengers that could fit
Speaker 1: on a single flight. After all, the airlines were no
Speaker 1: longer restricted to a regulated airfare price. They didn't have
Speaker 1: to compete on the basis of service. They could compete
Speaker 1: by offering lower airfares, and they can make up the
Speaker 1: difference by putting more people on a single plane, so
Speaker 1: they could actually make more money per trip even by
Speaker 1: offering lower airfares per customer. By doing the old stand by,
Speaker 1: you make it up in volume, and after balancing out
Speaker 1: the pros and cons of delivering a superior experience to
Speaker 1: the alternative of just going for the cold hard cash,
Speaker 1: most airlines went the cold hard cash route, and thus
Speaker 1: we started down the pathway of encountering aircraft with decreasing
Speaker 1: amounts of leg room, narrower seats, and other features that
Speaker 1: fuel stand up comedian routines. These huge aircraft are really expensive.
Speaker 1: They also can't fit on all runways, and not every
Speaker 1: airport can accommodate them. They were used for routes where
Speaker 1: it made the most economic sense to use them, typically
Speaker 1: on those transcontinental or trans oceanic flights. These tend to
Speaker 1: be long range aircraft because they are more expensive to purchase, maintain,
Speaker 1: and operate. Airlines typically have fewer of them in their fleets,
Speaker 1: so they dedicate them to these long range routes. Enter
Speaker 1: the narrow body aircraft. These became popular starting in the
Speaker 1: nineteen sixties, but they really took off pun intended after deregulation.
Speaker 1: They tend to be much less expensive to purchase, maintain,
Speaker 1: and operate than their larger cousins. They can fit in
Speaker 1: more airports and more runways, and they played into an
Speaker 1: economic strategy that airlines used to compete against each other
Speaker 1: because there was one other thing you could do to
Speaker 1: use to your advantage besides the level of service or
Speaker 1: the price of the airfare, and that was the frequency
Speaker 1: of flights for specific routes. Now this really got going
Speaker 1: with deregulation and the emergence of new airlines. Now passengers
Speaker 1: could have a lot more options. When they were booking
Speaker 1: a trip earlier, you might have a route that only
Speaker 1: had two or maybe three flights per day between two cities,
Speaker 1: so the passenger had to fit their schedule with the
Speaker 1: airline schedule. But with more routes approved and more narrow
Speaker 1: body aircraft in fleets, airlines had the chance to increase
Speaker 1: the frequency between certain cities that had demand that warranted it,
Speaker 1: and as you would imagine, most of the time, this
Speaker 1: would involve cities that had regular traffic between them. You
Speaker 1: weren't suddenly going to see an enormous increase in flights
Speaker 1: to some city that was far out of the way
Speaker 1: of everything else. Because there's no demand between two cities,
Speaker 1: it makes no sense to operate hourly flights between them.
Speaker 1: But for some routes that's exactly what did make sense.
Speaker 1: So airlines began to compete by telling customers, hey, we
Speaker 1: operate enough flights to your destination that you don't have
Speaker 1: to worry about conforming to our schedule. We've got a
Speaker 1: flight that fits your schedule. So this was the era
Speaker 1: in which we saw the narrow body mid range aircraft
Speaker 1: come into prominence, and that included the Boeing seven thirty seven.
Speaker 1: The original seven thirty seven was introduced by Bowing in
Speaker 1: nineteen sixty six. It was nicknamed a square airplane because
Speaker 1: the length of the aircraft was the same as the
Speaker 1: width of its wingspan. Both were approximately ninety three feet
Speaker 1: or a little more than twenty eight meters. It's a
Speaker 1: twin jet engine aircraft and the original seven thirty seven
Speaker 1: had an engine mounted under each wing. This becomes an
Speaker 1: important element when we get to the design of the
Speaker 1: seven thirty seven Max. Now there are different versions of
Speaker 1: the seven thirty seven that have different dimensions. The original
Speaker 1: seven thirty seven one hundred innered service for the airline
Speaker 1: luft Hanza, among others. United Airlines expressed interest in purchasing
Speaker 1: some seven thirty seven's, but that airline wanted a slightly
Speaker 1: longer version of the aircraft, so Boeing adjusted it and
Speaker 1: then created a version of the seven thirty seven called
Speaker 1: the seven thirty seven two hundred, and There are several others,
Speaker 1: including the recent seven thirties even Max Okay so aircraft,
Speaker 1: like the seven thirty seven from Boeing and the A
Speaker 1: three twenty from air Bus, served similar purposes to act
Speaker 1: as a short or mid range aircraft capable of carrying
Speaker 1: around two passengers, which varies depending upon the aircraft's configuration.
Speaker 1: By two thousand six, Boeing had been relying upon the
Speaker 1: seven thirty seven design for forty years, when the company
Speaker 1: began to consider the possibility of an entirely new design
Speaker 1: to fill essentially the same function as the old, reliable
Speaker 1: seven thirty seven. That decision was a huge one and
Speaker 1: would require a lot of steps, So Bowing kicked the
Speaker 1: idea down the road a few times, and then we
Speaker 1: get to two thousand eleven and American Airlines ordering the
Speaker 1: two hundred Airbus aircraft. It sent a signal to Boeing
Speaker 1: that delays we're going to cost the company big time.
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Speaker 1: stuff to learn more. Now let's get back to the
Speaker 1: seven thirty seven Max Alright. I left off saying that
Speaker 1: Boeing concluded that developing an all new type of aircraft
Speaker 1: wasn't going to pun intended fly. As Airbus began to
Speaker 1: gain popularity among airlines and American airlines had as part
Speaker 1: of its plan and order for a re engined seven
Speaker 1: thirty seven aircraft. Boeing would need to focus on that effort,
Speaker 1: and it abandoned the design of an entirely new aircraft.
Speaker 1: It finally said, Okay, it doesn't make sense for us
Speaker 1: to create a new aircraft from the ground up. Let's
Speaker 1: go back to the seven thirty seven and make some adjustments.
Speaker 1: This also brought with it a few other potential benefits.
Speaker 1: Developing a new aircraft is time consuming and incredibly expensive.
Speaker 1: Not only is the development process itself expensive, then there's
Speaker 1: the certification phase, in which the aircraft must pass requirements
Speaker 1: set by the various aviation authorities around the world in
Speaker 1: order to be allowed to operate as a commercial aircraft.
Speaker 1: And then there's the training phase. Pilots have to train
Speaker 1: on the new aircraft to learn its systems and how
Speaker 1: it flies. Not all aircraft behave the same up in
Speaker 1: the air, and that means it's a really big deal
Speaker 1: to invest in an all new type of aircraft. It's
Speaker 1: asking for a lot of resources, both from the manufacturing
Speaker 1: company and the various airlines out there. Updating and existing
Speaker 1: design is far less daunting. The basic bones for the
Speaker 1: aircraft are already there, and if the changes are within
Speaker 1: certain parameters, you can get through regulations pretty easily. After all,
Speaker 1: the base aircraft has already been through that process and
Speaker 1: had been approved. Likewise, if the changes aren't dramatic, pilots
Speaker 1: might be able to fly those planes without any real
Speaker 1: additional training or having to go into any flight simulators,
Speaker 1: because the aircraft, at least in theory, is going to
Speaker 1: perform within the basic parameters of its predecessors. So there
Speaker 1: are a lot of strong business cases for sticking with
Speaker 1: a previously engineered design. Boeing's decision to stick with the
Speaker 1: seven thirty seven was both more economical and, due to
Speaker 1: the agreement it had reached with American Airlines, pretty much necessary.
Speaker 1: One of the big goals Boeing had was to improve
Speaker 1: fuel efficiency so that the seven thirty seven Max could
Speaker 1: fly the same distance as older seven thirty seven's while
Speaker 1: burning less fuel. That would also mean the seven thirty
Speaker 1: seven Max could potentially have an increased range of flight
Speaker 1: compared to earlier seven thirty seven's, and you could argue
Speaker 1: that ultimately it was this push that would lead to
Speaker 1: the tragedies of the two seven thirty seven Max crashes
Speaker 1: that would ground the global fleet of seven thirty seven
Speaker 1: Max aircraft. It's a sort of cascade effect where one decision,
Speaker 1: that being to re engine the seven seven would lead
Speaker 1: to other decisions that ultimately set the stage for catastrophe.
Speaker 1: And by the way, this is all very easy for
Speaker 1: me to say in hindsight, I'm not trying to suggest
Speaker 1: that I would have spotted the potential for disaster before
Speaker 1: it happened. It's only because it happened that we're able
Speaker 1: to go back and analyze this and see where the
Speaker 1: mistakes were made. But at the time it was not
Speaker 1: necessarily that clear, at least not outside of Boeing. Boeing
Speaker 1: chose for this new version of the seven thirty seven
Speaker 1: some engines from a company called CFL. CFM is actually
Speaker 1: a joint venture between g E Aviation and Saffron Aircraft Engines.
Speaker 1: So in two thousand eight, CFM introduced a class of
Speaker 1: engines they called the Leading Edge Aviation Propulsion Class or
Speaker 1: LEAP l E a P. Boeing opted for the Leap
Speaker 1: one B model of engines, which has a thrust range
Speaker 1: between twenty three thousand and twenty eight thousand pounds of
Speaker 1: thrust or between one hundred and one killing Newton's of
Speaker 1: thrust and Newton is the amount of force required to
Speaker 1: accelerate an object with a mass of one kilogram and
Speaker 1: an acceleration of one second per second. CFM chose several
Speaker 1: engineering advancements that contributed to better fuel efficiency and its
Speaker 1: leap engines compared to older aircraft engines. That includes carbon
Speaker 1: fiber composite components that are stronger than earlier materials at
Speaker 1: a fraction of the weight, so while the engines are
Speaker 1: big larger than previous seventh D seven engines, they don't
Speaker 1: necessarily weigh as much as those older engines do. CFM
Speaker 1: also used additive manufacturing, more commonly called three D printing
Speaker 1: to produce those components. The leap engines also pre mix
Speaker 1: fuel and air together before the mixture hits the nozzles
Speaker 1: that enter the fuel into the combustion chamber, So older
Speaker 1: engines would inject essentially amissed a fuel into the combustion
Speaker 1: chamber and the mixing of the fuel and the air
Speaker 1: happened inside the chamber itself. But according to CFM, that
Speaker 1: meant lower fuel efficiency and greater emissions, So they say
Speaker 1: that this new method cuts down on emissions and you
Speaker 1: burn more of the fuel. The engines would give Boeing
Speaker 1: the boost and efficiency needed to meet American airlines requirements.
Speaker 1: In August two thousand eleven, Bowing officially announced the development
Speaker 1: of this new version of the seven thirty seven, and
Speaker 1: the company began to market the aircraft to various airlines.
Speaker 1: By December two thousand eleven, Boeing found a customer in
Speaker 1: the form of Southwest Airlines, which put in an order
Speaker 1: for one fifty of the aircraft. Aircraft that were in
Speaker 1: the earliest stages of development, mind you. From two thousand
Speaker 1: eleven to two thousand fifteen, Boeing worked on the design
Speaker 1: and production of the seven thirty seven Max. And here's
Speaker 1: where we see some other decisions that would ultimately contribute
Speaker 1: to the problems we saw when it entered service. The
Speaker 1: new engines were larger than the previous seven thirty seven engines,
Speaker 1: as I mentioned earlier, and traditionally those earlier seven thirty
Speaker 1: seven engines would be mounted under the seven thirty seven's wings,
Speaker 1: but these new engines were too big to do that
Speaker 1: and still allow for adequate ground clearance between the bottom
Speaker 1: of the engine and the ground itself, So that meant
Speaker 1: the engineers had to figure out where to put these
Speaker 1: engines on the body of a seven thirty seven, and
Speaker 1: ultimately they decided to move the engines forward along the body,
Speaker 1: ahead of the wings, and their position in such a
Speaker 1: way so that the exhaust of the engines is directed
Speaker 1: underneath the wings, which makes sense. You wouldn't want it
Speaker 1: to go right up against the wings you melt your
Speaker 1: own wings off. And also the way that their position
Speaker 1: now means that the bottom of the engine has sufficient
Speaker 1: ground clearance. But moving the engines forward had another consequence.
Speaker 1: It changed how the aircraft moved in flight. Moving the
Speaker 1: engines forward meant that in flight, the seven thirty seven
Speaker 1: Max has a slight tendency to tilt its pitch upward,
Speaker 1: in other words, to tilt its nose up towards the
Speaker 1: sky in a climb. That can be a problem for
Speaker 1: lots of reasons, but a big one is on takeoff.
Speaker 1: I mean, obviously you're climbing in takeoff, and in that phase,
Speaker 1: pilot's guide a plane into a climb to reach cruising altitude.
Speaker 1: So you don't want a plane to overcompensate and tilt
Speaker 1: further back than the plan to climb for lots of reasons,
Speaker 1: but a big one is that it can cause the
Speaker 1: engines to stall out. So for a jet engine to work,
Speaker 1: you have to have air flow going through that jet
Speaker 1: engine in sufficient quantities, so it has to be moving
Speaker 1: there in a sufficient speed. Essentially, I covered this in
Speaker 1: recent episodes, so I'm just going to do a quick overview.
Speaker 1: In a jet engine, incoming air hits fan blades that
Speaker 1: compress that incoming air, which then either flows in or
Speaker 1: around a combustion chamber where the engine ignites fuel. The
Speaker 1: resulting hot gases in the combustion chamber expand and then
Speaker 1: force their way out of the chamber through an exhaust
Speaker 1: nozzle in the back of the chamber, and as they
Speaker 1: escape they hit rotors on the rear side of the engine,
Speaker 1: and the rotors connect through a shaft to the fan
Speaker 1: blades that are in the front of the engine. So
Speaker 1: as that exhaust is coming out the back of the engine,
Speaker 1: it hits the rotors, and the rotors turn because of
Speaker 1: that rapidly escaping gas, and because that's connected by a
Speaker 1: shaft to the blades in the front, it turns. The
Speaker 1: fan blades in the front of the engine, and the
Speaker 1: whole thing perpetuates itself because of this continuous burn inside
Speaker 1: the combustion chamber. But for this to work, you have
Speaker 1: to have a sufficient amount of air flowing into the
Speaker 1: engine in the first place. This is also why it's
Speaker 1: necessary to jump start a jet engine on the ground.
Speaker 1: They forced compressed air through the jet engine in order
Speaker 1: to get it going, because you cannot get it started
Speaker 1: any other way. Now, if the plane were to tilt
Speaker 1: too far in an incline when it's climbing up into
Speaker 1: the sky, the angle of the engine compared to the
Speaker 1: airflow would be such that you wouldn't get enough air
Speaker 1: to go through the engine for it to maintain operation,
Speaker 1: and that's why it would stall out. You would have
Speaker 1: a lack of air to keep that whole process going.
Speaker 1: Installed engines would clearly be a disaster. Once Boeing engineers
Speaker 1: recognize the tendency for the seven thirty seven Max designed
Speaker 1: to go into this unprompted tilt, they had to how
Speaker 1: to address that problem, and their solution was a combination
Speaker 1: of hardware and software. On the hardware side, they relied
Speaker 1: upon sensors that would automatically analyze the difference between the
Speaker 1: airplane's attitude in the air and the angle of attack.
Speaker 1: So the angle of attack describes the angle of a
Speaker 1: plane's wing with respect to airflow. Angle of attack is
Speaker 1: a big component of lift, that's the force that keeps
Speaker 1: aircraft in the air. The other major hardware component is
Speaker 1: the aircraft's horizontal tail, which can tilt to change the
Speaker 1: plane's pitch. By altering the orientation of this horizontal tail,
Speaker 1: it could act as kind of like a rudder, except
Speaker 1: a rudder for the horizontal access, not the vertical, and
Speaker 1: the effect is that it could force the nose of
Speaker 1: the plane back downward in one of these climbs, so,
Speaker 1: in other words, it could affect the pitch of the airplane.
Speaker 1: The software overseeing the whole operation of this, which would
Speaker 1: monitor the data coming in from the sensors and then
Speaker 1: send appropriate commands to the tail, is called the Maneuvering
Speaker 1: Characteristics Augmentation System or m CASTS. So if you've been
Speaker 1: following the story of the seven thirty seven Max, you've
Speaker 1: likely heard the term m CAST thrown around now. In theory,
Speaker 1: m casts would operate in the background and make the
Speaker 1: seven thirty seven Max perform as if it were any
Speaker 1: other type of seven thirty seven aircraft, so it was
Speaker 1: designed to override pilot controls. But this also meant that
Speaker 1: if the system were to erroneously detect that the aircraft
Speaker 1: were in too steep a climb, the tail flap or
Speaker 1: the horizontal tail rather could force the plane into a
Speaker 1: dive and the pilots would be struggling to pull out
Speaker 1: of it, and they'd have to figure out how to
Speaker 1: do that, and that would also mean knowing how to
Speaker 1: disarm the system. Okay, so Boeing was pushing hard to
Speaker 1: get the seven thirty seven Max ready to compete with
Speaker 1: the Airbus A three twenty neo aircraft. The f a
Speaker 1: A helped expedite things. In two thousand fifteen, according to
Speaker 1: the Seattle Times, the f a A managers put pressure
Speaker 1: on the agency's safety engineers, telling them to delegate the
Speaker 1: assessment process to Boeing's own staff. This, by the way,
Speaker 1: it doesn't seem like it's completely unusual, but it did
Speaker 1: come as something of a surprise to me. I did
Speaker 1: not know that's how things worked, because, in other words,
Speaker 1: what that means is the agency and charge of overseeing
Speaker 1: safety passed that job along to a company that produced
Speaker 1: the very thing the FAA was meant to oversee. And
Speaker 1: that might sound like it might not be the best idea.
Speaker 1: I happen to think it was a pretty bad idea now, granted,
Speaker 1: as we are now seeing, a failure on the part
Speaker 1: of a company to be completely honest and rigorous with
Speaker 1: its safety assessment process can result in terrible tragedies for
Speaker 1: passengers as well as real hardships for the company itself.
Speaker 1: So companies like Boeing have a very strong incentive to
Speaker 1: police themselves care late. However, it sounds like that's maybe
Speaker 1: not what happened with Boeing's self assessment. Again. According to
Speaker 1: the Seattle Times, the safety analysis understated how far the
Speaker 1: im cast software could force the horizontal tail to move
Speaker 1: in an effort to stabilize the planes pitch. The Times
Speaker 1: reported that in reality, the software was able to make
Speaker 1: the tail move more than four times further than what
Speaker 1: the report indicated, meaning a much more dramatic change in
Speaker 1: pitch than what Boeing was claiming in the report. And
Speaker 1: Boeing's response to this was that initially Imcast would be
Speaker 1: able to move the horizontal tail at an angle of
Speaker 1: point six degrees. It turned out it was more like
Speaker 1: two point five degrees, and Boeing said, well, it was
Speaker 1: only upon further study that we realized in order to
Speaker 1: pull out of a disastrous climb, you would need a
Speaker 1: greater movement than just point six degrees, which is why
Speaker 1: we increased it. But at that point we had already
Speaker 1: written the report. Seems to me like there might have
Speaker 1: been an addendum that needed to be added there, but
Speaker 1: what am I to say? So the report did not
Speaker 1: address how mcasts would reset after a pilot's response and
Speaker 1: would go into another dive despite repeated manual attempts to recover. So,
Speaker 1: in other words, if a pilot were to respond to
Speaker 1: this unplanned dive and pull back, you know, activate the
Speaker 1: control and pull back on it, then it would stop
Speaker 1: the system temporarily, but it would just reset and start
Speaker 1: the cycle over again, and it might get more dramatic
Speaker 1: each time. The the amount of of of tilt that
Speaker 1: the horizontal tail would take, and thus the amount of
Speaker 1: dive the plane would go into, would get greater each time.
Speaker 1: The criticism is that the safety measure had no self
Speaker 1: correcting process that would discontinue the diving efforts after manual intervention.
Speaker 1: It would just keep going into a dive. So the
Speaker 1: argument is that there should have been a system in
Speaker 1: place where if a pilot intervenes, it deactivates this process
Speaker 1: that was not in place. The Times criticized that the
Speaker 1: assessment stated that if the system were to fail, it
Speaker 1: would merit a hazardous danger rather than a catastrophic one.
Speaker 1: These have real meanings in safety assessments. Hazardous means that
Speaker 1: the outcome could result in injury or death to a
Speaker 1: small number of passengers in a plane. Catastrophic is essentially
Speaker 1: a designation stating that such a failure would result in
Speaker 1: the complete loss of the plane and everyone on board.
Speaker 1: So Boeing was saying that a failure of the system
Speaker 1: would merit the hazardous level, not the catastrophic level. So,
Speaker 1: in other words, the criticism is that the report was
Speaker 1: downplaying the actual outcome of a system failure. One other
Speaker 1: major problem is that Boeing neglected to include information about
Speaker 1: m casts in its operation manuals for the seven thirty
Speaker 1: seven Max. Pilots didn't know about it, airlines didn't know
Speaker 1: about it. It wasn't until after the first tragedy that
Speaker 1: this would be amended. When we come back, I'll talk
Speaker 1: about that accident and the following events. But first, let's
Speaker 1: take another quick break. Perhaps because the f a A
Speaker 1: delegated the safety assessment duties to Boeing, Perhaps because the
Speaker 1: seven thirty seven Max was a variant on a tried
Speaker 1: and true aircraft design that had been an operation for
Speaker 1: at that point fifty years. Perhaps because simulations failed to
Speaker 1: create the sort of scenarios that we would unfortunately see
Speaker 1: unfold in the actual operation of the aircraft. The seven
Speaker 1: thirty seven Max past certification without much hullabaloo. Then, to
Speaker 1: be fair, it seems in more investigations that some of
Speaker 1: those simulations actually did show some problems, but Boeing didn't
Speaker 1: really address that at the time. There was also no
Speaker 1: need to train flight crews on how to operate the
Speaker 1: seven thirty seven Max, because in theory it behaves so
Speaker 1: much like other seven thirty seven's, particularly the seven thirty
Speaker 1: seven in G, which was the immediate predecessor of the Max.
Speaker 1: Pilots reported that they essentially had to complete a one
Speaker 1: hour course on a tablet and not even spend any
Speaker 1: time in a simulator before they would be certified to
Speaker 1: fly a seven thirty seven Max. However, you want to
Speaker 1: lay it out. The end of the matter is that
Speaker 1: the seven thirty seven Max received its certification and Boeing
Speaker 1: began to deliver the aircraft to customers. One of those
Speaker 1: customers was Melindo Air, a carrier based out of Malaysia
Speaker 1: and a subsidiary of a larger airline called Lion Air.
Speaker 1: On October twenty ninth, two thousand eighteen, Lion Air flight
Speaker 1: j T six ten, which was a seven thirty seven
Speaker 1: Max eight, crashed just thirteen minutes after takeoff from Indonesia.
Speaker 1: The plane crashed into the sea off Jakarta. All one
Speaker 1: eighty nine people on board died as a result of
Speaker 1: that crash. Among them were twenty Indonesian government officials. The
Speaker 1: plane had been in use for about two months. A
Speaker 1: pilot had reported a problem with the aircraft right away,
Speaker 1: requesting a return to the airport before they lost control
Speaker 1: of the aircraft. The CEO of Lion Air at the
Speaker 1: time reported that a different pilot had reported the same
Speaker 1: plane for a quote technical issue end quote earlier on
Speaker 1: that week, but that the aircraft had been cleared to
Speaker 1: fly the following day. An investigation following the crash indicated
Speaker 1: that one of the angle of attack sensors had malfunctioned
Speaker 1: on the Lion Air flight, and it had mistakenly indicated
Speaker 1: a dangerous change in pitch and an oncoming engine stall,
Speaker 1: and none of those conditions were actually existing at the time.
Speaker 1: But the im CAST software and system went into action,
Speaker 1: forcing the horizontal tail to move the the the nose
Speaker 1: of the plane downward and put it into a dive.
Speaker 1: The pilot was unable to counteract that, and the plane
Speaker 1: crashed as a result. Making matters worse was the fact
Speaker 1: that Boeing had not indicated the im cast was even
Speaker 1: a thing. The pilots had no way of knowing what
Speaker 1: it was that was causing the plane's nose to dive
Speaker 1: or how they were supposed to stop it. On November six,
Speaker 1: two thousand eighteen, Boeing issued a report revealing im CAST
Speaker 1: to pilots and airlines for the first time. The report
Speaker 1: also gave instructions to pilots on how to override in
Speaker 1: cast in the event of a failure. Not At this point,
Speaker 1: it wasn't yet certain that im casts was at fault,
Speaker 1: but the signs were starting to point that way. In
Speaker 1: the meantime, Boeing continued to receive orders for the seven
Speaker 1: thirties seven Max from various airlines and was still in
Speaker 1: full manufacturing mode. One thing Bowing did that later drew
Speaker 1: an enormous amount of criticism was to place some responsibility
Speaker 1: on the pilots themselves, stating that they should have known
Speaker 1: to cut off the switches to the planes stabilizers. But
Speaker 1: analysts who looked at the recovered flight data for the
Speaker 1: Lion Air disaster said that what the pilots had experienced
Speaker 1: didn't look like a stabilizer runaway scenario in which an
Speaker 1: element like the seven thirty seven Max's horizontal tail would
Speaker 1: make a continuous, uncommanded movement. The Lion Air flight data
Speaker 1: showed that the tail movement was not a continuous motion,
Speaker 1: and then the pilots were able to use the controls
Speaker 1: to pull up several times before the plane became uncontrollable.
Speaker 1: The analysts contradicted Boeing, saying that it wouldn't have seemed
Speaker 1: obvious to cut off the stabilizer controls based on what
Speaker 1: was happening then. On March tenth, two thousand, nineteen, and
Speaker 1: Ethiopian Airlines flight from Addis Ababa to Nairobi crashed not
Speaker 1: long after takeoff. Air traffic control lost contact with the
Speaker 1: plane just six minutes after it left the runway. All
Speaker 1: one fifty seven people aboard that plane died from the crash.
Speaker 1: Early analysis suggested that once again, this was a failure
Speaker 1: of m CAST. Further investigation showed that the crew attempted
Speaker 1: to follow Boeing's instructions to correct for the failure, to
Speaker 1: no effect. One day after the crash in Ethiopia, China,
Speaker 1: and Indonesia, authorities issued orders that all seven thirty seven
Speaker 1: Max aircraft operating in those countries were to be grounded. Now,
Speaker 1: at that point, it was not yet known that m
Speaker 1: CAST was definitely at fault for that second crash. The
Speaker 1: day after that, on March twelve, two thousand nineteen, Canada,
Speaker 1: the EU, and India also ordered all seven thirty seven
Speaker 1: Max aircraft grounded. The f a A in the United
Speaker 1: States would follow suit one day later, on March thirteenth,
Speaker 1: two thousand nineteen. At that point, investigators were seeing signs
Speaker 1: that IMCAST did play a part in the second crash.
Speaker 1: The U s Department of Justice began a sweeping investigation
Speaker 1: into the matter, and particularly into the process of the
Speaker 1: jets certification. How could it pass certification if it had
Speaker 1: this incredible flaw. That investigation has uncovered other concerning details
Speaker 1: about the issue, including the revelation that a Boeing pilot
Speaker 1: had brought concerns about the flight system of the seven
Speaker 1: thirty seven Max to the attention of Boeing officials back
Speaker 1: in two six. Previously, Boeing management had maintained that they
Speaker 1: had no idea that the flight control system could cause
Speaker 1: a catastrophe, but pilot Mark Fortner said that while flying
Speaker 1: simulations that incorporated m CAST, he had encountered cases where
Speaker 1: the flight management system was, in his words, quote running
Speaker 1: rampant end quote. The revelation of this pilot's warnings came
Speaker 1: a little more than a week before Boeing CEO Dennis
Speaker 1: Muhlenberg and John Hamilton's Boeing's lead engineer, were to appear
Speaker 1: before the United States Senate and the United States House
Speaker 1: of Representatives and back to back hearings. During those hearings,
Speaker 1: officials accused Boeing of purposefully downplaying safety issues and concealing
Speaker 1: potential problems in an effort to achieve certification as quickly
Speaker 1: as possible and thus start selling planes as quickly as possible.
Speaker 1: Those officials are also concerned about the f a a's
Speaker 1: practice to deputize the very companies it is supposed to
Speaker 1: certify in the safety assessment process. Now that's not to
Speaker 1: say that the US government is now advocating for sweeping
Speaker 1: changes in certification or or even going to come down
Speaker 1: hard on Boeing, because it's not as simple as that.
Speaker 1: At issue isn't just the fate of Boeing, which is
Speaker 1: an enormous employer in the United States. That also means
Speaker 1: that there's a whole lot of folks who are potentially
Speaker 1: voters who could be affected by any massive problems that
Speaker 1: Boeing faces, and politicians are a little squeamish about doing
Speaker 1: things that could potentially upset voters. There are airlines that
Speaker 1: have aircraft they can't use. They're dealing with this problem
Speaker 1: to they're looking at lost revenue. And there are all
Speaker 1: these companies that supply bowing with components like GE, you know,
Speaker 1: one of the companies responsible for the seven thirty seven
Speaker 1: max engines. GE has had its own share of problems recently.
Speaker 1: You can listen to my episodes about General Electric that
Speaker 1: published not too long ago to learn more about those.
Speaker 1: Because the seven thirty seven max is effectively on hold.
Speaker 1: It could potentially cost companies like Ge and others billions
Speaker 1: of dollars. Boeing, for its part, has made major changes
Speaker 1: to m CAST. A big one was that moving forward
Speaker 1: in CAST will take into account both angle of attacks
Speaker 1: sensor before changing the horizontal tails orientation. It would no
Speaker 1: longer accept just one stream of data as being enough
Speaker 1: to change the plane's pitch. One of the other major
Speaker 1: criticisms directed at Boeing from a design level is that
Speaker 1: the MCAST sensor was a single point of failure with
Speaker 1: no redundancy, and when coupled with Boeing's self assessment that
Speaker 1: a failure just represented a hazardous outcome but not a
Speaker 1: catastrophic one, create a false sense of security. Another big
Speaker 1: change is limiting how much the tail will move like
Speaker 1: I said. The original safety assessment said the tail would
Speaker 1: only move point six degrees, but in practice it was
Speaker 1: more like two point five degrees at maximum. Boeing has
Speaker 1: also stated that it is going to limit the system
Speaker 1: to activating for a single cycle, as opposed to the
Speaker 1: reset repeat process that was seen in both Lion Air
Speaker 1: and the Ethiopian Airline crashes. Then there's the long tail
Speaker 1: stuff that Boeing is going to have to deal with,
Speaker 1: stuff like trust and perception. While Bowing has made efforts
Speaker 1: to address the problems in its seven thirty seven Max
Speaker 1: flight systems, the company's credibility has taken a hit, as
Speaker 1: has the perception of the f a A. There's still
Speaker 1: lawsuits against Boeing that are making their way through the
Speaker 1: legal system that are a direct result of the seven
Speaker 1: thirty seven Max disasters, and Boeing still has hopes that
Speaker 1: the aviation agencies around the world will lift the grounding
Speaker 1: of the seven thirty seven Max aircraft before the end
Speaker 1: of twenty nineteen or in early twenty twenty. Meanwhile, the
Speaker 1: company has another headache to deal with. In October two
Speaker 1: thousand nineteen, reports came out that aircraft operators had discovered
Speaker 1: cracks on the seven thirty seven in G aircraft, or
Speaker 1: at least some of them now. As I mentioned earlier,
Speaker 1: the seven thirty seven in G is a predecessor to
Speaker 1: the seven thirty seven Max. It's been in service for
Speaker 1: several years. It doesn't have the m CAST software or
Speaker 1: the engine placement of the Max, and it remained in
Speaker 1: operation with any problems. But in early October two thousand, nineteen,
Speaker 1: U S officials ordered an inspection of seven thirty seven
Speaker 1: in G planes that had completed more than thirty thousand cycles,
Speaker 1: that is, more than thirty thousand takeoffs and landings. And
Speaker 1: the whole point was to look at the section of
Speaker 1: the plane where the wing attaches to the body of
Speaker 1: the plane. It's a part of the plane that is
Speaker 1: called and I swear I'm not making this up the
Speaker 1: pickle fork. Several airlines outside of the United States also
Speaker 1: began to inspect their seven thirty seven in G s,
Speaker 1: even those that had not yet completed thirty thousand cycles,
Speaker 1: and reportedly some of those aircraft have had cracks appearing
Speaker 1: in the pickle fork as well. Boeing stated that out
Speaker 1: of the one thousand, seven thirty seven in G s
Speaker 1: that had been inspected so far, inspectors that only indicated
Speaker 1: that five percent of them have had cracks. Still, it's
Speaker 1: another indicator that things are not going so great for
Speaker 1: Boeing right now. We'll have to wait and see how
Speaker 1: this all plays out, whether or not the seven thirty
Speaker 1: seven Max will return to service, whether or not people
Speaker 1: will trust it. You've had a lot of us politicians
Speaker 1: already saying that they would not get on a seven
Speaker 1: thirty seven max to take a trip based on what
Speaker 1: they've seen. So there may be an inherent trust that
Speaker 1: ends up being an enormous barrier to the seven thirty
Speaker 1: seven max, even if the technology is proven to be safe.
Speaker 1: So that's a huge issue. Once you've eroded trust, it's
Speaker 1: very hard to rebuild. So we'll have to wait see
Speaker 1: how that turns out. I am very curious to see
Speaker 1: it myself. I've definitely been interested in this subject. I
Speaker 1: fly fairly frequently, and knowing about this is something that
Speaker 1: I think is important. Um, it's also something that fills
Speaker 1: me with anxiety if I'm being perfectly honest, but I'd
Speaker 1: rather know than not know. Anyway, that wraps up this
Speaker 1: episode of tech Stuff. If you guys have suggestions for
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