Why the De Havilland Comet Failed
"De Havilland Comet: The Learning Curve - A Tale of Pioneering Triumph and Tragedy in Aviation History"
Join us as we unravel the captivating story of the de Havilland Comet, the world's first jet airliner, and its profound impact on aviation history. Our documentary explores the groundbreaking development of the Comet I in post-war Britain, an emblem of technological advancement and national pride. Witness its remarkable journey from its inaugural flight in 1952, soaring twice as fast and high as its contemporaries, to the unforeseen series of tragic events that unraveled its future.
Delve into the historical context of 1946, when the UK strived to rejuvenate its dormant commercial aircraft industry amidst the looming threat of American dominance. Discover how the Comet, equipped with pioneering turbojet engines, presented a revolutionary leap from traditional piston-engine aircraft, promising to halve air travel times. Uncover the engineering marvels and challenges behind this sleek, pressurized jetliner, and the ambitious efforts of the de Havilland Aircraft Company, supported by BOAC, to make it a reality.
However, the Comet's trailblazing journey was marred by catastrophe. Learn about the series of crashes in Rome, Karachi, Calcutta, and the mid-air disintegration of BOAC flight 781 in 1954, which cast a shadow of doubt over the aircraft's safety. Follow the intense investigations that ensued, uncovering the critical role of metal fatigue in the fuselage and the miscalculations that led to these disasters.
This documentary also addresses the myths surrounding the Comet's design, notably the misconception about square windows, and highlights the real issues that contributed to its downfall. Witness how the Comet's challenges led to transformative changes in aircraft design philosophy, from "safe life" to "failsafe" approaches, and set new standards in aviation safety.
Concluding with the Comet 4's launch in 1958 and its eventual eclipse by competitors like the Tupolev Tu-104, Boeing 707, and Douglas DC-8, we reflect on the Comet's enduring legacy in aviation history. This saga is not just a story of technological triumphs and failures but a lesson in the relentless pursuit of knowledge and the imperative of learning from adversity. Join us in this enlightening journey through the rise and fall of the de Havilland Comet, a true pioneer of the jet age.
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To contact me directly: Dashboardglobal@techie.com
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Our channel is about Aviation.
We make the best educational aviation videos you've ever seen; my videos are designed to clear misunderstandings about airplanes and explain complicated aviation topics in a simple way.
You make no mention of the punched rivet holes, as opposed to drilled.
Thank you for addressing the 'square windows' myth. I have written numerous pieces and delivered lectures on this including writing the the 'Window myths' section on the Wiki page on Comet. I also included a photo I took in 2019 of a surviving Comet 1 at the DeHavilland Museum, clearly showing that the passenger windows were very similar to the B 737 window but laid on their sides. The term 'windows' has been one of the most unfortunate terms in aviation history. These were not 'passenger windows' but ADF Loop antenna cutouts in the roof above the pilots. There were also existing manufacturing defects in the aircraft, one of which in G-ALYP existed around a bolt hole near the ADF antenna cutout. Passenger 'Window shape' was never mentioned as a contributing factor in the Cohen report or any subsequent examination of the facts. The stress data from the Comet investigation was made freely available to all manufacturers.
The Cohen report calls them "ADF aerial windows"
That's why I said "The term 'windows' has been one of the most unfortunate terms in aviation history." @@PRH123
Excellent video.
Great video but you might want to check your stress figures, you might have meant pounds per square foot as opposed to pounds per square inch. 50,000+ psi would be equivalent to a water jet used to cut metal and stone. Atmospheric pressure at sea level is only 15 psi.
The figures given describe the tensile strength of the metal, not the 'air pressure' inside the fuselage. Pressurizing the fuselage stretches the skin, like an inflating balloon. The stretching force is the force that stresses the skin and causes cracks.
Ah, understood, thanks!
Might also want to check dates, amongst other aspects as well as realising that BOAC is a set of initials and NOT a word.
Boke? I’ve never heard that.
I came to ask what a 'Boke flight' was
Such a beautiful jet .... damn those square windows LOL
It had an amazing appearance. Could look modern in even by todays standards
HOLY HELL 5 MINUTES?! good vid btw
Sorry what happened in five minutes please?
@@Dwaynesaviation i saw your vid 5 minutes after posting. Good vid btw
Boeing, quality and safety are words that are seldom used in the same sentence, nowadays!
In the end, it was a case of de Havilland engineers using just too thin a skin for the plane. Had the skin been a tad thicker, this problem may not have manifested itself until much later.
1952. Problem was not enough was known about the effects of compression and decompression, nor metal fatigue. Had certain designs been different, it may have resulted in compete success, but no one knew. Also no computers then to calculate the stresses or model them. Today Boeing still can't get it right. Their MAX 8 malfeasance and deliberate shortcutting- deliberate, not accidental, killed far more people than all the Comet tragedies combined.
That's one of those enduring comet myths. Engineers very well understood aluminum metal fatigue from the 1920's. Even the DC3 from the 1930's was designed to a specific number of takeoff/landing cycles.
when you put luggage on a plane but you do not take your seat guess what happens,
The plane doesnt leave the ground.
It was never pronounced 'boke'. It was British Overseas Airways Corporation, or the letters B.O.A.C..
*Exemplary!*
This video doesn't fall into the square windows trap, so there is that. But you should look more closely at rhe Generative AI created graphics. At 4:00 the graphic for The Comet was developed between 1946 and 1949 with the aircraft rising on an ogive bell-curve shape between those two years is one of the worst demonstratives I have ever seen. I hope it was a result of insufficient editing of the AI outputs and not of intentional human intent.
Too many mistakes and inaccuracies to take this at face value. If your number of 8.25psi of air pressure at cruising altitude is correct and the fuselage is pressurized to that of an 8,000foot altitude, which heavy jets usually are, which is 75% of surface pressure or 11.25psi, the difference in pressure between cabin and outside is only 3psi. Your stress numbers are absolutely off the charts, instead of psi they are probably psf. It is obvious to see in all the pictures of crashed parts that all breaks went through rivet holes. All the stress fractures originated from rivet holes, not because the skin was too thin but because the holes were punched, not drilled. Punching the rivet holes often left macro cracks in the material and that was the cause of the break ups. BOAC only decided to use slightly thicker materials in an attempt to regarner the market's confidence.
Get your facts right. The Comet first flew in 1949 and entered service in 1952, not 1958.
My fact stated: In 1952, the Comet made its maiden passenger flight from London to Johannesburg. Its jet engines, remarkably quieter than piston engines, allowed pilots to soar at unprecedented altitudes of 40,000 feet.... Comet 4 took the skies in 1958...
"BOKE"? You got to be shitting me? Obviously yet another so called content creator creating videos designed to teach their audiences about things that they haven't fully learnt about themselves or else they would never have used the wrong pronunciation, I would literally be much too embarrassed to keep this video up and would delete it before reposting a corrected edit of the video.
Get your years right
What year?
You have quite a few year-related errors in your post, I'm afraid. Almost embarrasing!
Sorry, what exactly is the date related error? What's the time stamp? I literally went over the script several times
It is pronounced B.O.A.C not Boke.