Is this THE END of the Boeing 737?!

Is this THE END of the Boeing 737?!

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-Why? Why oh, why is the Boeing 737 still around? (calm music) Now, I know that some of you might think that you know the answer to this, that it has to do with type ratings and training costs, but what I'm really asking here is something more fundamental. How is it even possible for the 737, a design that was dating back to the 1960s to still be able to compete in the year 2024? Stay tuned. (playful chime) Now, over the past few weeks, the Boeing 737 has been in the news almost continuously and for all of the wrong reasons. As I'm sure most of you know, back in 2019, the entire Boeing 737 MAX lineup was grounded worldwide, following two really tragic accidents. - One message described the 737 MAX as a plane designed by clowns overseen by monkeys.

- Now, resolving the issues that had caused those tragedies in a way that satisfied the FAA, EASA and all of the other aviation authorities around the world took about 18 months for Boeing to do and even after that, a lot of authorities still delayed it even further. Now, after the MAX was eventually let back into the air, there followed a few years of relative calm until on the 5th of January this year, 2024, an Alaska Airlines 737 MAX 9 served a blow-up of a mid-cabin door plug, leaving a gaping hole in the fuselage for terrified passengers to look out through. Now, as I've explained already before, this was not a Boeing 737 MAX issue and what I mean by that is that it didn't have anything to do with the actual design of the 737 MAX itself.

Instead, it was likely a quality control issue. Now, I've already made a couple of videos looking into that event and I have a feeling that I might still have to make a couple of more as soon as this embarrassing story comes to its eventual conclusion. But one question that a lot of you guys have been asking throughout this debacle is the one that I actually started this video with.

Boeing started producing the 737-100 already back in 1966. This means that they have now been making these jets non-stop for over 57 years and that is an insanely long production run. And remember, Boeing still has enough orders to keep the 737 in production until at least 2030, so how is that possible? One thing that makes the 737's long career even more amazing is that it was originally only supposed to be a kind of stopgap or quick fix by Boeing.

But to understand what I mean by that, we have to talk a little bit about the aircraft that Boeing introduced immediately before the 737, the lovely Boeing 727. In the 1960s, it was the 727 that was supposed to take care of the short to medium-haul market for Boeing. At least that's what the Boeing management thought at the time. But the design of the 727 was always going to be a little bit of a compromise because some airlines wanted a really powerful jet that could fly in and out of short runways at high density altitudes, whilst other airlines preferred something with only two engines for a better overall economy. On top of that, some airlines also needed at least three engines to enable them to fly over-water legs safely at a time when regulations didn't permit twin-engine aircraft to be more than 60 minutes away from an alternate airport. Also, almost everyone wanted an aircraft that would sit low on the ground, making it easier for airport staff to load and unload baggage by using minimal ground equipment and also to make integrated air stairs more practical.

All of these requirements meant that the engines had to be mounted on the back of the fuselage because at the time there was no engine that would fit under the 727 wing. So that's why the 727 was designed with its three engines in the back and the engine that Boeing had initially selected for it was a version of the Rolls Royce RB 163 Spey low-bypass turbofan. The Spey and its derivatives were very successful engines, who powered a lot of different aircraft at the time, both commercial and military. But as it turned out, Boeing would later change their mind and redesign the 727 to use the Pratt & Whitney JT8D low bypass turbofan instead. Now, this engine was a bit more powerful, but it was also a bit more heavy, which initially cancelled out that power advantage, but it showed good development potential and crucially, it was also a bit smaller in diameter, which will become very important later on in this story.

Boeing first flew the 727 in February of 1963 and then entered it into service about one year later. But almost immediately after they had introduced it, they realized that they had a problem. They had originally planned to make two versions of it. The first one was the 727-100, which was the shorter of the two, practically seating up to about 125 passengers or so, and then they had the 727-200, which was longer and would initially seat around 150-160 passengers. But the problem that Boeing soon discovered was that even the smaller 727-100 was a bit too big for that market segment. And on top of that, it was also a bit too complicated and heavy for some prospective airline clients.

Remember, the reason it had those three engines was to give it a lot of excess power to enable it to operate from short runways, sometimes high up, but not everyone really needed all of that excess power. Now, fuel efficiency wasn't a big concern back in those days, at least not for the financial reasons it is today, since the fuel was really, really cheap, but a high fuel burn also meant that it had a limited range. And having three engines instead of two also increased maintenance costs dramatically.

Maybe you're seeing where this is going now. Now, the aircraft that really showed Boeing that they had a problem was the Douglas DC-9, a twin-engine design that was smaller than the 727, and on top of that it also needed just two pilots in the cockpit and no flight engineer. Douglas launched the DC-9 in 1963 and Boeing soon realized that they would need to respond to this new rival in some way. After considering a shorter two-engine version of the 727 and realizing that it probably wouldn't work, Boeing soon switched to a design with a narrower fuselage that would only have five seats per row, but with now two engines still fitted in the back. And then, on a sunny afternoon, a very clever Boeing engineer called Joe Sutter realized something. Remember how I mentioned that those Pratt & Whitney JT8D engines were a bit smaller in diameter than the Royce-Royce engines were? Well, this meant that those new engines actually could fit under the wings and still allow the fuselage to be as low as the airlines, and therefore Boeing really wanted.

Now obviously other Boeing engineers had probably figured this out before Sutter, but the design of the 727 was too far along at this stage to redesign it with the engines under the wing. But what Sutter had worked out was that moving the engines to the wings would not only be possible, it would also enable the new DC-9 competitor to have a much lighter fuselage, and that would make it possible to give the new model, which they would choose to call the 737, the same six-people-per-row layout as the 727 had. Boeing would therefore be able to reuse a lot of the 727 fuselage construction for this new aircraft, and this would be a really, really valuable shortcut.

Because remember, this all happened in the mid-1960s and Boeing already had a lot on its plate at that time. Now, if the name Joe Sutter seems familiar to you, it's probably because he is also known as the father of the Boeing 747. Obviously, this magnificent beast of a plane would come out a little bit later, but Boeing was already working on conceptual studies around the jumbo jet as early as in 1963.

And you know what else happened in 1963? Well, Britain and France officially launched the Concorde back then, and this meant that Boeing, who had already been working on supersonic aircraft studies before that, now realized that they would need to press ahead and develop a supersonic answer to the Europeans, whilst also working on the 747. So yeah, Boeing was extremely busy at that time, but they still chose to go ahead and add the 737 into the mix by launching it in 1965. The initial model was, like I mentioned before, the 737-100, which was built to seat around 85 to 110 passengers, but soon after, this slightly stretched 737-200 would come to replace it, with a cabin only slightly smaller than that of the 727. Now, I'm sure many of you know that the 727's fuselage, which the 737 effectively borrowed, was actually itself borrowed from the even older 707, which had entered service already back in 1958.

So, while the 737 has been in production for 57 years, many parts of its design actually date back another eight or nine years, making it as old as Swedish Fish or as the Rolodex. - [Man] Ja. - Now, I'm not going to list all of the 737 variants in this video, because we really don't have the time to do that, but the point I'm trying to make here is that the 737 is not only old, it also had some design compromises right from the very, very start.

And yet, here it is, still with us and slated to stay in production for many more years to come, so how is that even possible and is there now an end in sight for it? Well, I'll tell you all that you need to know about that after this.... About six months ago, I was going through a bit of a rough spot professionally. I felt that I was getting overwhelmed with all of my different work roles and that caused me to procrastinate and not get things done, even though I had enough time to do it. Around that same time, I was approached by today's sponsor, BetterHelp, to see if I wanted to work with them. Now, I told them that I only work with brands that I use myself and therefore, I wanted to test them out before agreeing.

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The aircraft that should have replaced the 737 was a design that I've actually mentioned in a few of my previous videos, a concept called the 7J7. And that aircraft was actually supposed to replace both the 737 and the 727. Well, at least sort of. In theory, the aircraft that actually ended up replacing the 727 was the Boeing 757, in my view one of the absolute best-looking airliners of all time. The 757 also had a good amount of excess power, which I actually had the privilege to try out myself in a simulator in Iceland recently.

Awesome, awesome experience. Anyway, that extra power gave it the ability to operate from high altitude airports with relatively short runways, just like the 727 was designed to do. But it could do so whilst also being able to carry a lot more passengers.

The biggest 727, the 200 had an emergency exit limit of 189 passengers, but in practice, it wouldn't carry anywhere near as many as that. The smallest 757 on the other hand, the 200, had an exit limit of 240 passengers and would routinely fly with 200-plus passengers on board. Now, some airlines liked that huge lift in passenger capacity, but many actually didn't.

Again, it was more capacity than what they actually needed. So in practice, updated versions of the 737, like the 737-400, were instead replacing many older 727s already back in the 1980s. But by that point, Airbus was busy developing the A320 family, broadly to take up the competition with Boeing for that same role. Now, Boeing really wanted to revolutionise this segment of the market with the open fan 7J7.

This plane would be the first Boeing to have fly-by-wire. It would also make extensive use of advanced composite and new lightweight metal alloys, but, of course, its main advantage would come from those open fan engines. Had Boeing succeeded with this, the 7J7 would have outclassed the Airbus A320 in terms of efficiency, right from the very start, but unfortunately for Boeing, that didn't happen. Now, there were two open-fan engine designs considered for the 7J7, one by Pratt & Whitney and another one by GE and Safran, but both of those designs proved to be too immature to enter service, so Boeing instead used a lot of the technologies that it was developing for the 7J7 in their new fantastic Boeing 777.

And to keep Airbus and their A320 family at bay, they also updated the 737 a second time, introducing the 737-NG family. Now, even before the NG, the 737 Classic had been fitted with better and more economical CFM56 engines and the NG got a further updated version of those, together with better wings and avionics. But no matter how much better that engine upgrade was, it wasn't really revolutionary, like the open fans of the 7J7 would have been, but at least they were the same generation as the engines on the Airbus A320 family. The Boeing 737-NG and the Legacy Airbus A320 families were close enough in efficiency to enjoy a healthy competition for around two decades, but by then, in the late 2000s, Pratt & Whitney and CFM were ready to launch their next engine generations. Pratt & Whitney developed the Geared Turbofan and CFM, a joint venture between General Electric and Safran, introduced the Leap-1, with each design bringing its own advantages. And that is how we get from the A320 to the A320neo family and from Boeing 737-NG to the MAX.

Now, the full story of how Boeing was pushed to develop the 737 MAX instead of designing something entirely new is a quite fantastic one and it involves some really clever backroom politics between Boeing, several involved airlines and Airbus. Now, I will tell you more about that in a coming episode, which I'm really looking forward to, so make sure that you have subscribed so you don't miss that one, and when you're down there, give me a like as well. Go on, I'll wait. Anyway, the real question that I came here to answer was how the almost 60-year-old Boeing 737 is still able to compete with much newer designs and that's why I keep talking about its engines.

You see, the best way to understand this is actually by looking at another pair of aircraft and how they have been competing with each other. When Boeing introduced the 787, they were bringing together every possible element they had to create the ultimate modern airliner. The 787 had modernized, simplified systems, minimizing hydraulics; it had a fuselage and a wing made out of lightweight composites and, of course, it has the latest generation of high bypass turbofan engines. Now, Airbus also introduced an ultra-modern wide-body a few years later, but its design, the Airbus A350, is a bigger aircraft which is better-suited to compete against the Boeing 777 and maybe the largest version of the 787, the 787-10. But in order to compete against the smaller 787-8, and 787-9, Airbus would instead launch the A330Neo. Now, this was basically a re-engined A330 with a few smaller updates, like new winglets and a slightly updated and optimized wing, so you would think that with all of the fancy new technologies it introduced, the Boeing 787 should have been much more efficient than the almost ancient design of the Airbus A330neo, right? Well, the realit,y as Scott Hamilton in Leeham News explains, is very, very different.

The Airbus A330neo family is powered by the Rolls-Royce Trent 7000, and the 787 comes with two engine options, either the General Electric GENX or the Rolls-Royce Trent 1000. Now, the Trent 1000 of the 787 and the Trent 7000 of the A330neo is essentially the very same engine. The 787 has replaced a lot of hydraulic systems with electric ones, so the engines lack the hydraulic pumps that would normally drive those systems, but beyond that, the Trent 7000 is basically a version of the 1000, with both engines having the same fan diameter. And because of that, even though the A330 was designed in the early 1990s and with a fuselage dating back to the A300 of the 1970s, on many routes, its efficiency is within a couple of percentage points of that of the all-new, all-composite 787.

That is amazing, when you consider that something like a new pair of winglets or even a reshaped tail cone can often give around 2% advantages to a new airliner. So, basically, the point that I'm trying to get across here is that engines aren't just a big factor in defining the efficiency of airliners today. They are overwhelmingly the most important factor. Far more important than any construction materials or other design quirks as long as the fundamentals of the aircraft are good. So, maybe this makes Boeing's decision to re-engine the 737NG and create the 737 MAX a little bit easier to understand. Yes, obviously this also made it possible for the airlines to fly both the 737NG and the 737 MAX with the same crews, which obviously helped operations and eased training requirements, but that would not have been even a discussion if the aircraft wasn't also competitive.

Now, like I said before, there is much more to that side of the story, but it is worth pointing out that this kind of recycling thinking which led from the 737NG to the MAX isn't entirely new. Even with the original 737, Boeing could sell the six abreast cabin layout to the airlines by telling them that they would be able to use the same interiors as those that they were already using on the 727 and even on the 707. Of course, justifying the reuse of an existing aircraft design to bring forward another generation instead of something completely new is one thing.

How that idea is then executed is another and a very different story as the first grounding of the 737 MAX sadly showed. But I also asked another question in the beginning of this video. How long will the 737 be able to continue doing these rebirths? How long can we continue putting new engines on an old design before it is no longer efficient enough to be competitive? Well, as far as the 737 is concerned, one way or another, we can safely assume that it's now at the end of its road. We know that Boeing won't develop another 737 variant after the MAX-10 is released, but that's primarily due to regulatory requirements. But there is also another efficiency-related reason.

Even if the 737 MAX can't keep up with the Airbus A320neo family in terms of efficiency, the same isn't necessarily true when it comes to the practically brand new Airbus A220. A few months ago I actually made a video where I explained how the A220 could potentially become an A320neo killer. It was Bombardier who designed the aircraft as the Bombardier C-Series before selling it to Airbus, so at its inception the C-Series or A220 today was actually meant to be a strong A320 competitor. And as I'm sure what's really obvious by now is that whatever is a threat against the A320neo family, it's also a threat against the 737 MAX. At the moment, the largest available Airbus A220 is the A220-300, which has about 15 fewer seats than the smallest Boeing 737 MAX variant, the Dash 7. But the perceived efficiency of the A220-300 is measurably better than that of the 737 MAX-7.

And crucially, the A220 was designed from the very beginning to be stretched even further. The longer model would be comparable in capacity to the Airbus A320neo and really close to the 737 MAX-8. And that, my friends, is a very big deal. You see, the 737 MAX-8 is, by far, the single biggest moneymaker for Boeing at the moment. And some analysts believe that a stretched A220 would have a two-digit efficiency advantage over the MAX-8. Now, some other analysts think that the two jets are probably a little bit closer to each other than that, but either way, this kind of advantage is not something that Boeing can afford to ignore.

So this means that even if Boeing, right now, have very shaky finances and they do after all of these problems, they will need to figure out a way to respond to a threat this big against their cash cow, the 737 MAX-8. So the only good news for Boeing right now is that Airbus probably aren't in a big hurry to get this stretched A220 on the road, since they are right now focused on making as many A320neo family jets as possible and their assembly lines are fully booked until well after 2030. But those lines are increasingly focusing more and more on the even bigger A321neo. If it would turn out that orders for the smaller A320neo would start to dry up, well then Airbus could start to transition over their focus on increasing the A220 production and possibly even to launch that stretched variant. When that stretched variant comes, that will likely be the aircraft that will finally kill the venerable 737, ending the longest production run of any commercial airliner ever. After this incredibly long run it's had, it would be a very tragic shame if this bird goes out on a disgrace, instead of being remembered as the enduring icon of commercial aviation, it so clearly is.

What do you think though? Let me know in the comments below and leave a like when you're down there. Now I will be discussing this with my Patreons in our coming Zoom Hangouts and I would love to see you there as well. It is an excellent way of being part of the production team here and on Mentour Pilot and your contributions are highly appreciated.

You can also support the channel and my team by either buying yourselves some merch or leaving a Super thanks using the dollar sign button here somewhere below. Everything is greatly appreciated. Now watch these videos next and have an absolutely fantastic day. Bye bye.

2024-02-16 18:28

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