In the previous introduction, I described an example of how to conquer uncharted territory, specifically how Comet attempted the world's first high-altitude, high-speed flight.
Let's examine how the Comet project was developed based on that methodology.
To understand the Comet project, let's look back at the global situation and Britain's position at the time (1943-1945), and also examine how much they understood about the technology.
Understanding the current situation (the surrounding circumstances) is crucial for investigating any phenomenon, so I would really appreciate it if you would follow along.
World situation at the time of Comet's planning
To understand the problems encountered during development, let's briefly consider the social conditions, development processes, and the state of the manufacturing companies at the time.
The situation in the British government (1943–1947)
First, considering the situation of the British government, its national power had been greatly diminished by the damage caused by World War II.
For the British Empire, which ruled the seven seas until just before the Great War, the shift of global hegemony to the United States and the Soviet Union must have been unacceptable.
To recover its diminished national power and rebuild its global hegemony, it chose to create the world's first four-engine jet passenger aircraft.
To achieve a world first, we absolutely had to develop it faster than anyone else, no matter what.(I knew that the United States had also started working on it.)
It's easy to imagine that Britain, which prided itself on being at the forefront of aviation, was quite anxious, especially since the United States had been flying B-29s during the war.
If this world's first jet passenger aircraft is successful, then the futureIf Britain could control not only the aircraft of private jet passenger planes but also the operational systems and air traffic control systems, it would generate enormous financial and political benefits.
After the war, they probably aimed not only to conquer the seven seas but also to conquer all the skies on Earth.
The significance of achieving a world first
In Japan, there used to be politicians who would say nonsensical things like, "Is being second best not good enough?" (I wonder if there are still some around?), but being second best is not good enough.
I think it's equally questionable for people who can't answer immediately.
There are many reasons, but the country or company that is the first in the world to achieve something can control the standards and norms of that industry.
Being second place means you have to pay to learn the methods of the country or company that took first place, or buy parts from them, in order to actually produce what you want.
Another point to add is that by being number one, you gain know-how that others cannot acquire.
By consistently taking the top spot, the amount of know-how and advantages you can accumulate over your rivals will be exponentially greater.
A good example of a relevant and hot topic is the "coronavirus vaccine."
This discussion will not address the pros and cons of the early approved COVID-19 vaccine being RNA-based.
As of the time of writing, only company F, an overseas manufacturer, has had its vaccine approved and begun to be used.
Naturally, there are limits to how much vaccine production F Company alone can handle, given the needs of so many people worldwide.
As of the time of writing, according to the chairman of Company F, production is only possible in facilities built by the company itself (the author is skeptical; it's probably just an excuse for production shortages).
No matter how much we talk about the international community, it's only natural that Company F would prioritize supplying vaccines to its own country.
Many people in Japan also need the vaccine, but even if we request it from Company F, we can only purchase a limited number.
So, they proposed, "If F Company's production isn't enough, then if you teach us how to make it, we'll produce enough for our own use in Japan."
Company F will issue a contract stating that in exchange for granting production permission, they must "give some money" if production takes place in Japan. Furthermore, all know-how gained from production in Japan, as well as all the clinical data actually used, will be handed over to Company F.
This means that the more vaccines are produced in Japan, the more profit Company F makes, and the more they are used, the more know-how Company F accumulates.
On the other hand, even if generics were to be produced in Japan, the law would prevent their manufacture for several years. Furthermore, even if a new vaccine method were developed, its track record would be significantly lower compared to the pioneering F company. Therefore, if most people had a choice, it would be natural for them to choose F company's vaccine.
To put it in extreme terms, Company F only needs to develop the product, and then it will automatically make money and gain know-how without doing anything else.
Indeed, launching a product into the market early like this offers immeasurable advantages.
As of this writing, the US government is demanding that Company F relinquish its vaccine patent, but the real focus will likely be the struggle between the international political gains and the profits of pharmaceutical companies.
In any case, it will undoubtedly bring significant benefits to the United States, whatever form it may take.
In the field of industry, which is my area of expertise, I'm more interested in which company will be the first to achieve autonomous driving than in electrification.
Achieving autonomous driving will naturally require technological development in the vehicles themselves, which will necessitate a redesign of the entire transportation infrastructure.
If a country were to implement that transportation infrastructure system, it would have a monopoly on it for a considerable period of time.
ThenEntrusting not only the automobile itself, but also the core technologies of automobile-based logistics to other countries would leave Japan an extremely vulnerable society in terms of national defense, economy, and other aspects.
like thisPlease keep in mind that achieving something as a world first brings not only short-term financial benefits and drawbacks, but also a variety of other advantages.
Now that I've explained the importance of being a world first, let's return to Comet.
To that end, the government and private sector invested generously in this joint project.
To that end, they tried to poach engineers who had worked on the jet fighters that were put into practical use in Germany after the war, but those were all taken by the United States and the Soviet Union, so they decided to develop their own technology.
This situation forced Gent Engines to use an improved version of an existing centrifugal jet engine instead of a more promising axial-flow jet engine.
For these reasonsBritain was quite anxious to realize the world's first jet passenger aircraft.
The situation of the development and manufacturing company (de Havilland) (around 1945)
On the other hand, the development and manufacturing company (de Havilland) will inevitably see a decline in performance as military aircraft orders drop significantly after the war ends.
Therefore, in order to survive, they must secure many orders for passenger aircraft, which will be the main market during peacetime and will likely last for a long time.
That's when they turned their attention to developing and manufacturing the world's first four-engine jet passenger aircraft.
Therefore, the company's fate was at stake.It's not hard to imagine.
Furthermore, the development and manufacturing company (de Havilland) was founded in the early days of aviation (1920) and is a prestigious company with numerous world records in aviation history.
This company produced the DH.88 Comet (fighter) and DH.98 Mosquito, military aircraft that were considered legendary during World War II.
The wooden Mosquito fighter jet was produced using adhesives for joining the parts, and that know-how led to the manufacturing method of dividing and gluing together the pressurized chamber of the Comet fighter jet.
A trap had already been set in place.
Furthermore, this company produced the Vampire, the second jet fighter to enter service in the UK.
The Vampire was not just a simple jet fighter; it featured a pressurized cabin and a bubble canopy (teardrop-shaped windshield), and was a masterpiece with over 3500 units produced, suggesting considerable confidence in its technology.
To put it in modern terms, it was a leading company in the aircraft industry (similar to modern-day Lockheed or Boeing).
Naturally, the employees are likely to be elite individuals who graduated from prestigious British universities such as Oxford and Cambridge.
Furthermore, there must have been many engineers who had gained a wealth of know-how and experience by fighting through the brutal competition of war.
From a business perspective, the time is ripe.It wouldn't be surprising to think that way.
Technological situation before the development of the Comet (around 1945)
Next, let's consider the technical situation at the time.
First, regarding stress concentration and fatigue failure, which were identified as major causes of the accident, they were generally known at the time, although their understanding was naturally less advanced than it is today.
Stress concentration situation (circa 1945)
First, to give a brief history of stress concentration, records show that Leonardo da Vinci (1452-1519) conducted stress concentration tests.
The degree to which stress (load) is concentrated due to the shape is called the shape factor, and the foundation of most of this research was established by 1940.
ObviouslyAll of these events occurred before the development of the Comet.
SoMany engineers were aware that stress concentration would occur at the corners of windows and around the antenna openings during the development of the Comet aircraft.
Fatigue failure status (circa 1945)
Regarding fatigue failure, significant developments occurred during the 18th and 19th centuries, following the Industrial Revolution.
Especially at that time, the main mode of transportation was the railway (train), so as the railway matured, the field of fatigue failure also developed significantly. By 1947, when the Comet was developed, the railway had entered a mature stage, and similarly, the foundations of fatigue failure had also been solidified.
After doing some research on the history of fatigue failure, I found that in the early days of steam locomotives, the axles of locomotives broke down frequently due to fatigue failure (around 1830).
Fortunately, the locomotives at the time were traveling at a maximum speed of only about 24 km/h, so they were unlikely to cause major accidents. Also, since they were only running on tracks (rails), it seems that reproduction tests and other experiments could be conducted relatively easily.
With the development of steam locomotives, knowledge of fatigue failure also advanced, and by around 1940, even in Japan in the Far East, it was possible to safely operate the Asia Express in Manchuria at a top speed of 130 km/h.
In other words, Many engineers understood fatigue failure at the time of the Comet's development.
As evidence of this, Comet underwent fatigue testing during its development phase.
The background of the Comet's core technologies: the jet engine and pressurized cabin (1945)
Next, let's take a brief look at the background of the jet engine and pressurized cabin, which are the highlights of the Comet's mechanism and structure.
Regarding jet engines, they were put into practical use in Germany during the war, and almost simultaneously, they began to be adopted for military aircraft in various countries. In Britain, the Gloster Meteor entered service in 1944 (centrifugal jet engine).
On the other hand, regarding pressurized cabins, the United States adopted them in the B-29 during the war, and even Japan, which was behind in this field, managed to complete a small version of it just before the end of the war.
Naturally, research and development of pressurized cabins are also being conducted in the UK, and their technological level is by no means low.
Furthermore, observational data on the environment (temperature, atmospheric pressure, etc.) at the altitude of 12000m where the Comet flies had been gathered through reconnaissance during the war, and sufficient data was available.
Furthermore, the company that developed and manufactured the Comet had previously produced numerous small passenger aircraft called the DH.89 Dragon Rapide, which was considered a legendary aircraft.
In other words, Even though it was small, the development and manufacturing company possessed a great deal of know-how regarding passenger aircraft.
Thus, all the necessary data for the mechanisms, structures, and environments required for the development of Comet was readily available. To put it in slightly more technical terms, the various elemental technologies necessary for realizing Comet were established at a reasonably high level.
So, what was truly a world first? It was the first time that a jet engine had been used to conduct passenger flights at high altitudes in a pressurized cabin.
In other words, This combination of elements was truly a first (jet engine + huge pressurized cabin + passenger).
Similar to the development of the F-35 Joint Strike Fighter, which I explained last time, the individual technologies were established, but this was the first time they had been combined.
Here tooThe scary thing is that there are pitfalls, and because of the individual skills involved, it might seem easy to achieve at first glance.
SimplyEven when combining things for the first time, there are many unknowns about what will happen, making it very difficult.
In other words, unless engineers look at it with an accurate and honest eye, it will just be a pipe dream.
This gives a general overview of the situation and background at the time.
In short, the British government spared no expense or human resources in achieving this world-first project, a matter of prestige, but at the same time exerted immense pressure to expedite its completion, likely setting a specific deadline.
At that point, de Havilland, the company that developed and manufactured the Comet, gained confidence from its past achievements and stepped forward to win the contract.
The world's first four-engine jet passenger aircraft, the Comet.
Let's now consider the problems that arose during the planning of Comet in chronological order.
In terms of the basic development flow I previously described, this corresponds to the conceptual stage.
The stage described here as conceptualization or conceptual design involves considering everything from defining the concept as explained in the section on dealing with unknown territories, to determining the technical challenges and solutions for tackling those unknown territories.
It appears that the British government took the lead in developing this concept for the Comet (similar to the government-led development of a certain domestically produced passenger aircraft, the MRJ).
From market research to project planning by the British government
In 1943, then-Prime Minister Churchill, in order to demonstrate his country's advanced position in the post-war civil aviation sector and to investigate market needs, established the Branson Commission, chaired by Robert Branson Tara, a prominent politician and influential figure in the aviation industry from his own Conservative Party. The commission was tasked with developing four specific plans that were considered likely to become mainstream in post-war civil aviation.
Four different designs were completed in 1944 and presented to each airline.
Comet Development and Manufacturing received the order for the plan known as Type 4 out of the four options.
The concept for this Type 4 was a jet mail transport aircraft capable of high-speed transatlantic flight, but for some reason, the development and manufacturing company announced that it would develop a large jet passenger aircraft (later the Comet) that was completely different from the government's plan.
As explained earlier, it's easy to imagine that behind this, they came up with a grand and seemingly very attractive plan in order to make a huge profit in one fell swoop, driven by pride in having produced numerous legendary machines, excessive overconfidence in their own technology, and a sense of crisis stemming from a significant decline in future orders.
These kinds of things often turn out to be counting your chickens before they hatch, and you end up regretting it later.
For some reason, the government accepted the declaration and authorized the Comet Development and Manufacturing Company to begin development. They received provisional orders for two aircraft from the Ministry of Munitions and seven from the government-owned British Overseas Airways Corporation, and development began as a national project in 1946.
In other words, they were so dazzled by the development and manufacturing companies' plans that they abandoned their own considerations and ended up buying nine airplanes with a considerable amount of taxpayer money, even though their viability was still uncertain.
This is the firstIf the private sector proposes a different concept from the one presented by the government at the initial checkpoint, it's highly unlikely that the government would approve development using public funds.
AlreadyThe discrepancies between the government and the development/manufacturing companies had already begun during the planning stage; the cracks had already started to appear.
It isThis will become a major problem for the government's decision-making and its organization.
Because everything that was considered and decided by the Branzon Committee would be wasted.
We're already aiming for a world first, and now the nearly year we spent deliberating in the committee will be completely wasted.
The money spent on the committee's investigations and other expenses will, of course, be wasted.
Furthermore, the government, blinded by the prospect of honor and fame, readily abandoned their own plan and went along with the manufacturer's proposal after the Comet development and manufacturing company made its declaration.
Because of this, it became necessary to reconsider the concept for the new large jet passenger aircraft (later known as the Comet), which resulted in a valuable two-year delay between the order in 1944 and the start of development.
Commissioner Branzon's year-long review and budget were completely wasted.
In other words, A major problem was that the government was so swayed by the manufacturers' proposals that they changed the crucial concept, derailing the plan.
Furthermore, we spent two years reconsidering the concept.
This meant that there were now less than five years until the mass production Comet aircraft were delivered in January 1951, when the aircraft were completed.
ThereforeThe government's impatience likely grew considerably, leading to significant pressure on development and manufacturing companies.
Herein lies a major problem: the inability to restrain manufacturers from going rogue, the government's inability to uphold the concepts it itself decided upon, and the government organizations' inability to protect those concepts.
If the Branzon Commission had been in charge of developing Concept Type 4, a high-speed, trans-Pacific jet mail transport aircraft, the Comet would not exist, and therefore the series of crashes would not have occurred.
Furthermore, even if a jet mail carrier were to crash, the damage would likely not be as severe as that caused by the Comet.
Furthermore, if they had built a jet mail transport aircraft, they would have gained know-how for civilian jet aircraft, and it is highly likely that they could have developed a passenger aircraft with a similar concept to the Comet later without crashing.
While historical "what ifs" are taboo, they are acceptable if they serve as lessons.That is what the author thinks.
like thisGovernmentThe policy differed from the prefecture's initial intentions.Under these circumstances, the development of the Comet, the world's first four-engine jet passenger aircraft, began in earnest.
Next time, we'll cover the development of the Comet from the beginning.
To those who found this article helpful in understanding design:
Since we're on the subject, I'd like to recommend a book that's essential for mechanical design.
To be honest, the content is extremely unhelpful, but it can be used like a dictionary when you forget the details. If you read this article, you should be able to understand the content and use it effectively. It also includes commonly used standards, making it quite useful.
If you don't already own one, I highly recommend getting one, even though it's a bit pricey. However, new ones are expensive, so if you're considering buying a used one, I strongly recommend checking that the surface roughness conforms to the new JIS standard.
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