Comet? No! Nimrod? Yes!

Thank you for making these videos

Only on one with round windows 🙈

well the improved comet that has the round windows then yeah

Is the idea romantic? Sure. Would it be enjoyable more than once? Certainly not, four turbojet engines that close would be exceedingly loud.

Planely difficult

Plane difficultly.

It does sound that way but it isn't

Meanwhile the auto generated subtitles: welcome to playing difficult

Wi tu lo

Very true

Back then, the main focus of any investigation was to find what went wrong and fix it. These days it's mostly to protect corporate profits.

@@rrknl5187 I beg to differ! The whole investigation process for all aviation accidents and near misses is to find root causes and ensure they are eliminated! There is obviously pressure from corporate to make it quick and cover any guilt, but the investigations are always good!

@@totherarf The degree of corruption and influence to protect industry or protect pilots varies as you move through space and time. Watch the last Mini Air Crash Investigations video and tell me that wasn't a cover-up, to say nothing of what happened with the Max. I won't disagree that the attitude of "find the problems" over "punish the troublemakers" or "prove the aircraft works okay" gets far better results. But, between the national investigators (NTSB and relvant counterparts), investigators from manufacturers, and investigators from airlines, there are a lot of competing interests in any investigation, and we don't always succeed in keeping those interests out of the way of doing good work.

@@totherarf I'd suggest that you are both correct. The aviation industry probably holds itself to different standards than other industries in this regard. @RR KNL didn't specify the aviation industry, and in many other industries there are (to varying degrees) cover ups - construction, manufacturing, oil, gas, coal and mining have all faced transparency problems over the years when things go wrong - we've seen plenty of examples on this channel. @Mentour Pilot is a fantastic aviation channel which looks at, amongst other things, aviation incidents, accidents and disasters - not in a distasteful, insensitive or crass way - the content creator hopes to illustrate that the aviation industry is constantly learning and improving through post crash investigations - something that other industries could learn from.

The Mosquito original prototype at that! I was lucky enough to get to be invited by the curator to sit in it when I was a child. Don't think they would allow it today!

That sounds really cool! We've only been to England once (our first trip) and didn't travel about as much as we would have liked (we were getting our feet wet basically) -- this is definitely going on the list!

@@palmspringsmarythomson6354 I’m sure you’ll have a nice time but I’d recommend checking their website for opening times !

@@andrewrixon2347 oh I know, it’s not going to be anytime soon! We have a lot of comic-cons coming back this year. Hopefully 2023 if things don’t go squiffy. We were planning before 2019 to be able to make a trip for the Queen’s Jubilee time but best laid plans and all that…

@@palmspringsmarythomson6354 would also recommend iwm duxford in duxford near Cambridge

So if they were made properly, could square windows still be used in airplanes? Or are they inherently weaker than round windows?

@@BlackRavenFeather565 Concentrating stress on four corners of the window would require a lot of reinforcements making the aircraft heavier and more complicated than it has to be. It's even better to have bigger rounded window than smaller square one. That's why almost all aircraft windows are rounded. Not perfectly round though, just enough to spread the stress evenly over the edge.

@@BlackRavenFeather565 Any material that has a square edge cut into it will have a "stress riser" or concentration in that corner. It's something we learned in structural engineering class. So a filet or rounded corner will spread or redirect the stress rather than concentrating it. Shafts, slots in metal, and those holes for windows have the rounded edges to keep that from occurring. See this video for a visual around a square notch kzfaq.info/get/bejne/rKqKaNx6uM-ldIE.html and this one shows the stresses around a round hole kzfaq.info/get/bejne/a9OmdLen2pu7eYE.html. The stress moves around the curved surface, while it concentrates on the angled one. The repetition of pressurisation cycles will cause cracks the migrate throught the material until it fails. I could probably restate this better, but at least you can SEE what is being talked about with the two videos mentioned.

*Following this, the design philosophy in aviation gradually moved from Safe Life [...] to Fail Safe design* This is really interesting. The design philosophy changed from "let it crash and burn after X cycles" (ironically called "Safe Life", it's obviously a cost saving measure it should be called Save Costs) to "let it not crash and burn". I think that's a positive change.

@@holz_name No, that's not how it was intended to work. Safe Life was simply the designed lifespan of an airplane which should be safe to operate and after which it should be decommissioned. Like a car that is guaranteed to work for 150k km and then should be scrapped as it may become dangerous. The second approach is to make something that will be fail safe - should be safe even in case of failure. It's like a car without lifespan limit that may break after 50k km but will not kill you. It has much longer lifespan but requires regular maintenance to keep it safe.

Nope, the windows are rounded so the earth looks round in flight,. Remember the earth is a pizza on the back of a sea turtle. I won't even get into chem trails , 5G, HAARP and the evil bowl of Jello located in a volcano that controls the world.

I might be wrong, but the problems that square windows or metal fatigue effects more on pressurised airplane cabin.. I think I have seen small aircraft that fly in low attitude (with unpressurised cabin) that have square windows (not that 90 degree square, but with rounded edges)

@@bobroberts2371 you forgot the cat that pushes everything off the edge of the pizza every 100 years

I really hope one day he tackles McDonnell Douglas and DC-10 cargo door issues, and the infamous investigation and blatant colluding with the then head of the FAA.

Ezcept for the fact that the comets already had round off cornered and not pointy square windows already

There's a reason ships' portholes are not square, and it's exactly the same reason. The designers should have taken the hint.

The engines were also one of the Comet's fatal flaws, the inlets were changed to make the plane safer but no other aircraft in uses this horribly bad design

​@sandervanderkammen9230 There was nothing wrong with the Comet's engine position or intake position . There are some advantages for that design & some disadvantages for the podded pylon mount engine design.

@@petemaly8950 Since the point of failure had been found to be exactly the corners of the passenger windows and the automatic-direction-finding window t's evident the radiusing was not enough. "just add enough material to make it work" is not a great solution when there are weight constraints, and the material you are working with has not a fatigue limit.

@@petemaly8950 Since both the real-scale tests performed at Farnborough and the analysis of the wrecks shown the points of failures being exactly the corners of the passengers' windows and the automatic-direction-finding window, its' quite evident they didn't test enough before the first flight.

I've heard the same thing. Also, I heard the widows were designed with "squareness" taken into account so their shape was not really the problem. I wonder if it compounded the problem..?

@@lomaii2847 go away spammer

The rivet holes were punched instead of being drilled. Also the fact that they used the same pressure cabin for overpressure testing, then afterwards to test the number of regular pressure cycles that it took to fail came into play, as the overpressure test cold-worked the metal, changing its crystalline structure in a way that made it much more resistant to metal fatigue.

@TheJudgementalCat Try reporting that comment - it'll disappear, then reappear, despite breaking more than one of KZfaq"s own guidelines - spam and explicit material. Like many, many others I've had loads of comments disappear for no apparent reason - no curse words/swearing, no bullying, no sketchy terminology or "trigger" words, (certainly not knowingly) yet the comments keep vanishing. KZfaq don't give out warnings or even offer any opportunity to edit - the comments just disappear, which can be extremely annoying if they are detailed or lengthy, yet explicit spam is allowed - YT is broken

You are correct sir.

Interesting. Do you have, a sauce, sorry, a source.

@@Margarinetaylorgrease Rivert duHamel's video on YT covers it succinctly.

Square holes concentrated stress at the corners of the holes, allowing premature stress cracking of the fuselage, when the crack grew long enough to reach another window (window is any penetration of the fuselage, whether an actual window, or an antannae) causing a failure making the pressurized fuselage pop like a balloon. The British had almost no experience with pressurization at that point. Pretty much Boeing, and curtiss were the only companies that had built pressurized aircraft at that time.

Later versions of the comet would have these issues rectified, but it already had a bad reputation and by that time Boeing and Douglas had far superior aircraft in production. The Military however loved them for antisubmarine and airborne early warning use. The U.S. had a similar experience with the lockheed Electra propjet airliner that had a resonence problem, but once fixed had a long career with the U.S. Navy as the P-3 Orion.

@@kdrapertrucker The problems were never solved, the fatigue life of the aircraft was severely reduced as a result.

Ship builders. They knew round(ed) windows where the way to go.

@@RoadkillbunnyUK I always kinda wondered why ships don’t have square windows. So it’s a pressure thing?

None of the catastrophic in-flight structural failures were related to the passenger windows.. The aircraft's fuselage ruptured along the roof at the point of the fuselage hoop with the highest hoop stress. de Havilland made the hoops too weak, the skin too thin, lacked proper doubler plates and safe riveting techniques. 100s of fatal flaws were discovered in the wings, engine inlets, control systems even the toilets had to be redesigned to make the Comet safe to carry passengers.

@@sandervanderkammen9230 you here as well? Why am I not surprised 😃 Well observed, by the way.

@John Higgins Those 426 people that died because of de Havillands incompetence are still dead....

I recently saw a surviving example at the Yorkshire Air museum UK, a very visually striking aircraft with nuclear capability.

Sadly true

Imagine being like.... that one guy who was probably like "We should have done that test..." or however they figured out the problems. (I still need to watch the video but I swear there's always that one guy no one listens to.)

They ran tests, but probably not nearly enough, and the tests were not properly organized (some of the stress testing was on parts that had already been tested for overpressure (this changes the structure of the hull and invalidates the later tests). DeHaviland didn't allocate enough time and most importantly enough hulls for comprehensive testing. Boeing and Douglass were VERY slow to get into jet airliners, by the time Boeing brought the 707 into service it had a lot of data from the B-47 bomber (and the negatives from Comet) to work with. The other big problem Comet had was that especially the Comet 1 was VERY short ranged (it could not fly the Atlantic) and rather small. The 2,3 and 4 were bigger, but not of the size that was really needed for many routes. Comet was an attempt to do an end-run on existing airliners and make British Aviation a player. It didn't really work, but the Princess flying boat and Brabazon were even bigger failures (the Comet at least entered service, and served as an anti sub platform "Nimrod" for decades to come).

@@PlainlyDifficult Their is an easy demonstration that shows what happens. First punch sheet of A4 paper using a punch that is used to store papers in a ring folder, then carefully cut one of the holes into a square. Then put the paper into a folder and carefully rip it out, observing which hole rips first. The difference is considerable and similar to nicking the edge of cellophane in order to rip it. Research has now shown that it was a similar thing that caused the Titanic to break in half. The ends of bitumen filled expansion joints at intervals along the hull became the origin of a stress fracture. This was already known by Harland and Wolfe and the slots ended with a circular bulb, similar to a thermometer. Why these were cut on her sister ship, but not the Titanic remains a mystery.

Don't forget one thing that is sadly prevalent in disasters like this, the possibility that the engineers had either designed in extra strength or the &^%$##%^&*((**&^%$ management overruled their engineers. And you know the engineers were screaming bloody murder about replacing drilling the rivet holes with punching them. Well until silenced by the "genius" at the top.

That’s pretty interesting.

When trusting your gut feeling saves a whole lot of lives.

He was also on the board of Boeing advisors. Maybe a bit of conflict of interest.

@itsjohndell While I'm not doubting that Rickenbacker made that claim, (and by extension I'm not disputing your retelling of the claim) I have trouble actually believing it. It's a bit of a stretch to think that he noticed it on one flight when the aircraft would have gone through extensive testing with, apparently, no-one else picking up on the problem. The aircraft went through many hundreds of pressurisation/depressurisation cycles before the stress fractures became apparent, and there was no mention of excessive vibration anyway - admittedly a pretty vague term. Also, when did he publicly say this? Was it after the findings of the inquiry were made public? I suppose we'll never know the truth of the matter, but I have my doubts.

@@connclark2154 So? He saved lives.

Hindsight is always 20/20, it's easy to call the failure now that we know. Still, I'm a little surprised that not one of the engineers - experienced with pressure vessel designs - had an instinctive reaction to make the corners round.

The Liberty Ships had stress fractures and failures owing to square rather than radiused deck openings.

@@johnladuke6475 The corners were round.

​@@johnladuke6475 The windows had radiused corners. They proved the design was good during the extensive & protracted testing activities It's possible to use sharp 90° corners for the passenger cabin windows on a pressurised airliner, it's just a matter of making sure there's enough material for adequate strength around the window, if sharp corners & big square windows etc are used it results in a lot of unwanted & unnecessary extra weight which is the last thing we want for an airliner design.

Which flaw? The Comet 1 was permanently grounded and its airworthiness certificate was revoked after investigation uncovered over 100 design, safety, construction and materials flaws.

well, any kinds of explosives is a deadly problems for any airplane😂😂

@@davidaprians explosive diarrhea for example

Indeed but even the worst of 'em brung 'er in fer a landin'. Flight 800 notwithstanding as it had other issues.

@@Miki90Mar 😂

They still are, there have been a couple southwest hull loses in recent years

It was a beautiful plane!

Its shape is optimized for aerodynamics. Hence the reason the dreamliner looks like it. Other designs have compromised in favor of other design considerations at the expense of aerodynamics

@@connclark2154 For what? Areodynamics? Weight? Can you give a real life example? Its quite interesting. Its really funny how world comes full circle again. Like 'muricans came out with UCP cammo patern, inspired by japanese grey camo from 1900's :P.

I love how it looks so strangely similar to the first-generation Caravelle. (For those of you in-the-know, I was being facetious. For those of you not in-the-know, DH let Sud use the Comet's nose for the Caravelle).

The early bird gets the worm, but the second mouse gets the cheese.

It wasn’t a huge technological leap, as nearly every Comet misconception would have you believe. It was the first commercial jet airliner, but the TECHNOLOGY wasn’t groundbreaking. Boeing already had the swept-wing, PODDED engine B-47 stratojet flying TWO years before the first Comet flew; it also had a far more advanced swept tail design than the Comet’s straight prop-era tail design. The genius was in applying known technologies to a different market, not so much the plane itself. Also (largely unknown or ignored) is the fact that Boeing had already implemented a huge array of construction and fuselage features into the -80 design which would have made the structural failure of the comet impossible. Guess what? They did all of that BEFORE the Comet crashes. Spot welding instead of punch riveting, tear-strips in the fuselage, and above all else, the aluminum skin was MUCH thicker than the Comets - again, all included in initial design specifications before the Comet crashes. It is possible that while being a groundbreaking aircraft for commercial jet travel, de Havilland ALSO royally (no pun intended) screwed up!

@@EstorilEm Nazi Germany had the first jet-powered aircraft (the Me 262), and the first operational jet squadrons. B-47 was post-WWII, but the Convair B-36B/D's (post WWII w/jet engines and conventional engines on one aircraft was operational in 1946-47). B-47 was not fully operational until 1953.

@@EstorilEm The "tear strips" or rip-stop strips were lacking in the Comet I, no doubt to save weight. Virtually all American jet liners had/have them. Keep cracks from propagating. There are also other areas where ground tests, including wind tunnel testing doesn't show up potential catastrophic failures. The Lockheed Electra I, for example, a four-engine turboprop, was tested extensively in wind tunnel testing. Unfortunately, it did not reveal the dynamic augment of the outboard engine/nacelle, which, under certain conditions inflight hit the natural frequency of the wing. The result was the Tell City, Indiana, crash, killing everyone onboard. Until the cause was found, airlines were instructed to reduce the cruise speed, which did keep the phenomena from happening. That was very fortunate for me and my Dad, as we took the same flight number, on the same type of aircraft, the next day! When the cause was found, Lockheed beefed up the wing structure and made other changes. The "new" plane was called the Electra II. While it didn't remain in commercial service much longer, the Navy and Air Force adopted it with all sorts of anti-submarine gear, and called it the P-3 Orion, which remained in service until being replaced recently by the P-8.

The Comet Disaster was certainly not the result of cutting edge technology... rather the lack of modern technology. The Comet Disaster could have been easily prevented if de Havilland had simply followed existing, well-known Industry standards for the design and construction of all-metal aircraft with riveted aluminum alloys and cabin pressurization.

I didn't realise the Nimrod was a military version of the Comet, cool!

@@skylined5534 Yep it’s a Comet airframe with a anti shipping radar in the nose, a bomb / torpedo bay fitted underneath and an anti submarine magnetic object detector on the end of the tail. And it used similar Rolls Royce Spey engines as the RAF Phantoms and Buccaneers.

The Nimrod is a completely different aircraft designed by Hawker Siddeley 2 decades later... not a Comet.

@@skylined5534 its not a Comet.

Sandtbum The Nimrod started life based on a Comet 3 and production Nimrods were vased on the Comet 4, all design work being by the design team at Hatfield, in other words by DH.

The picture of G-ALYU ready to be destroyed was some how quite moving, who knows how many lives it saved…

Airbus builds fine aircraft and Rolls Royce great engines. Don't beat yourself down too much!

Oddly enough, this design could still be in use today. But it does not get *_ALL_* of the profits, so to corporations it is completely pointless. Being profitable is not nearly enough, whatever it is *_MUST_* get *_ALL_* the profits.

@@unvergebeneid airbus came about not through british but french and german consolidation, and RR would have their own problems on commerical jets such as the lockheed tristar

@@danielduncan6806 not strictly true, pylon mounted engines eventually won out for their ease of upgrade and ease of maintenance. the brits kept on the integrated engine though with their V-Bombers

If no one die, no one cares

The tragedy of the Comet Disaster is it could have been easily prevented if de Havilland had followed well-known and understood engineering standards for riveted aluminum airframes. Prior to the Comet Disaster de Havilland was still building aircraft primarily from WOOD and was years behind in aircraft design and construction technology.

@@sandervanderkammen9230 - Which "well-known and understood engineering standards" were these? De Havilland were working on the bleeding edge of scientific knowledge regarding materials - no civil aircraft of that size had ever routinely cruised at those altitudes before. Furthermore, the DH Mosquito fighter/bomber was designed and made of wood not because DH lacked experience working with aluminium, but because the entirety of the aluminium available to the British Empire had already been requisitioned for other purposes. The whole point was that any joiner, cabinet maker or piano builder in the country could turn their hand to making parts for the Mosquito - which among other things severely pissed Hermann Goering off. Boeing probably had the most experience building aircraft with pressurised cabins with the pre-war Stratoliner, B-29 and Stratocruiser - and when De Havilland released their data regarding metal fatigue in the wake of the investigation, Boeing's engineers freely admitted that if it hadn't happened to the Comet, it would have happened to the jetliner they were working on.

@@turricanedtc3764 Metal fatigue was not discovered by de Havilland, it was already known to aircraft manufacturers... all but de Havilland. The Comet Disaster investigations revealed 100s of fatal flaws, design flaws, material flaws, shoddy workmanship and appalling quality control.

@@turricanedtc3764 Absolutely false, de Havilland made several unsuccessful attempts at building aircraft from aluminum alloys. de Havilland was still building aircraft primarily from WOOD when the company went tits-up in 1958. The industry leaders like Boeing, Douglas, Junkers and Lockheed were building all-metal, pressurized monoplane airliners before the war while de Havilland was still building wood and fabric biplanes like the Dragon Rapide!!!

you mean 'more on safety and less on style'? The engines in the wing were a horrible unsafe design decision.

The Comet's shape, in particular the engine placement was a fatal flaw that caused at 3 crashes. No other airliner ever copied this deadly design error.

@@Stevie-J Aircraft engineers never place the engine inlets of a jet aircraft in the leading edge of the wing, this was a serious fatal flaw that was modified but still plagued later Comet aircraft.

@@sandervanderkammen9230 * laughs in TU-104 *

@@nickcher7071 You don't see the huge glaring difference??? The Tu-104 doesn't have the fatal flaw that the Comet has... think about it.

In the Comet it was a obliged choice, sinche the engines of the Comet I, Ghost 50 Mk 1, were a little underpowered for the aircraft, so De Havilland used the same "trick" of the Mosquito, that had the radiators in the wings to reduce drag.

The explosive decompression would have knocked the people out very quickly, if not instantly. Many on board were thrown headfirst into the ceiling of the fuselage by the decompression. On top of that, the shock to the lungs from the decompression would have quickly rendered them unconscious.

It would have been a very quick way to go...

The engines inlets are clear evidence of bad design at de Havilland. Wishful British thinking... the effects of metal fatigue in pressurized cabins was already well-known and understood by German and American manufacturers... de Havilland was doomed to failure because it was still building aircraft primarily from WOOD and was years behind in aircraft design and construction technology.

Junkers, Boeing, Douglas and Lockheed were already manufacturing pressurized cabins from riveted aluminum well before the Comet Disaster without any accidents... It was de Havillands negligence not cutting-edge technology that killed 426 people.

Sandybum, Drbummer teling lirs as always.

Absolutely. de Havilland were very, very inexperienced in building pressurised aircraft. Apart from one experimental Vampire, I don't think they had built ANY pressurised aircraft prior to the Comet. Boeing, on the other hand, had been building pressurised aircraft since 1938 - starting with the 307 Stratoliner. Before the Comet ever flew, Boeing had also built the pressurised B-29 Superfortress and the 307 Stratocruiser.

Thank you!

Not as well as the bribes Boeig paid out to sell their aircraft.

The riveting process was the source of the trouble, because the punch method had been used…

Indeed, Boeing and Douglass did more to the 707 and DC-8 than just give them round(ish) windows. The fuselages also had tear-straps that would stop a tear if one started. Boeing demonstrated the effectiveness of these by purposely slicing open a pressurized 707 fuselage in a publicity video.

Boeing manufactured the world's first pressurized airliners in 1938.. the 307 Stratoliner, B-29, 377 Stratocruiser were all pressurized. The Boeing B-47 was pressurized to 9.5 psi at 45,000 feet, significantly higher than the Comet.

@@Stevie-J The Comet Disaster is the worst engineering failure in aviation history.

Sandybum The B 29 and Stratocrasher were much lower pressure and the B 47 was a bomber, no passengers to consider. Also the B 47 had a bad aerodynamic problem making it dangerous, a feature inherrited by the 707 which killed many people due to losing control in normal flight, Boeing restricted the speed and altitude of the 707 while the B 47 had a 5 knots range from stall to maximum speed meaninng the flight crew had to costantly mmonitor and adjust the throttles.

Where it failed wasn’t a window. It was an antenna mounting on the cabin roof…

To be fair to the engineers, the windows weren't completely square, they had rounded corners, the radius was just too small.

@@allangibson2408 On the recovered aircraft it was the antenna mounting (squared holes as well). In the tested one it were the windows. Another problem were the rivets' holes. Punched instead of drilled, they were already microfractured.

The catastrophic in-flight structural failures were were not related to the passenger windows at all. The fuselage ruptured exactly where Pascals Law tells us it should, at the reinforcing hoop with the highest surface area at its weakest point.

The fuselage hoops were too weak, the skins were way too thin, there were not enough doubler plates and the design and construction of the rivet joints were substandard. 100s of modifications and reinforcements were required to make the Comet 4 airworthy. Earlier Comets were modified with round windows but were still unsafe to carry passengers and the Comet 1's airworthiness certification was permanently revoked in September 1958.

good one

Thank you!

@@PlainlyDifficult Yeah, I miss the foam finger and the wacky variety of maps! That was a great trademark bit for the channel.

I've noticed when people complain about comfort and service in coach they try to compare it to the 50's and 60's; what they don't realize is that back then flying at all was the equivalent of first class, and if you adjust for inflation the airfrare was more expensive than an equivalent first class ticket today.

But hey, you don't hear propellers or feel piston engine vibrations.

You're also paying a lot less for a ticket than what the inflation-adjusted airfare was back then.

Thank you!

The same reason I absolutely REFUSE to drive a vehicle newer than 10 years old... I won't even look at it. Cutting edge tech' bring cutting edge bugs... ;o)

@@gnarthdarkanen7464 Remote hacker controlled Teslas anyone?!

@@skylined5534 As if traffic ain't a borderline clusterf*** as it is... YAY!!! Let the 10 - 13 year olds GNU open-source all they need to play GTA with REAL cars!!! Maybe somebody should just develop an app' for that "Augmented Reality" Game!!! AND post it for public consumption... ;o)

At the time Depressurisation was not well known during the 60’s.

It also has Seaman Sergei Preminin, the sailor with the biggest brass balls in the history of the Soviet navy. The channel jiveturkey actually has a great video detailing the whole incident as part of his sub-briefs series.

@@tiberiusweaver-zeman2520 Sub Brief with Jive Turkey was the first 219 documentary I had ever seen in subsequent reason for asking. His episode on finding that there were survivors on the thresher and it was just declassified 10 months ago blew my mind.

Do I have your consent to find your location?

"The British state-owned airline ie BOAC (and largest operator of the Comet, not counting the later Dan-Air) was pretty much a proxy for the government’s thoughts on this as well, which is clearly shown in their initial handling of the Comet crashes which was borderline coverup status. " The consequent depth and level of accident investigation by the RAE and Cohen Committee - following the three fatal Comet hull failures - were completely revolutionary, setting the precedent for future air safety. It was a surprisingly open process. The cutting edge of aviation history is littered with accidents and incidents. It's how people learnt, improved and adapted from experience. "In any event, by their own admission (ie they DID initially test the frames and components to check for metal fatigue and structural issues) they WERE aware of potential dangers that wear and cycles cause on aircraft. Yet, they STILL screwed up the design." Evidence?

Ah yes but Boeing certainly never covered up anything, Typical American arrogance eh?

@@alexwinfield9540 I’m not a Boeing fan actually, luckily their shortcomings hardly reflect the most cutting edge aerospace companies in the world (most of which do indeed reside in the US) - save for EADS/Airbus which are hands-down my favorite aerospace / defense contractor.

Your eyes are wrong.

@@marioxerxescastelancastro8019 your opinion is wrong.

Later Comet Disaster investigations recovered wreckage that confirmed that the passenger windows were not the cause. But the original investigation uncovered that the Comet was structurally unsound and lacked adequate materials and safety factors. In particular the aluminum skins were fat too thin and the alloys too brittle. And the planes lacked basic rip-stop doubler joints between panels. The fuselage reinforcement hoops were too narrow and spaced too far apart to prevent cracks from jumping to other segments and the rivets were substandard and did not have proper quality controls.

​​​@sandervanderkammen9230 Kharzeestan Krappenz DiktorBummer Jurkzxoffenz etc and co - they should note good with much awestruckness & many extreme wondermentals. *UPDATE MORE BREAKING NEWS ETC* The skin was not found to be too thin. The original alloy used became unavailable & so an improved alloy was used. *_It's interesting that some of the aircraft on the list should really have been noticeably safer than the Comet due to being a similar type but of much later design & manufacture but they definately were not safer._* How things were back then - *_Accident losses - % of aircraft built._* DeHavilland Comet 4 UK 14% DeHavilland Comet all mks 17% Vickers VC10 UK 5% *_The DH Comet had better safety than or similar safety to many other commercial passenger aircraft of a similar era_* Douglas DC-1 99% Douglas DC-2 47% Douglas DC-3 30% Douglas DC-4 26% Boeing s300 72% Boeing 307 70% Boeing 247 48% Boeing 707 20% Lockheed Electra Turboprop 29% Fairchild FH-227 30% McDonnell Douglas DC-8 14% Sud Aviation Caravelle 15% Canadair CL-44 Turboprop 46% Convair CV-580 Turboprop 22% A comparison of more recent aircraft. Accident losses comparison examples. 1970s - 1980s % of total Aircraft built Similar aircraft type, date / decade, useage, size. Biz Jets BAe-125-800 1.7 % Beechcraft Beechjet 400 2.2 % Cessna 550 Citation II 7.1 % Learjet 35 / 36 12 % Beechcraft 1900 6% Dassault Falcon 10 11.5% Aérospatiale SN.601 22.5% Medium size jets / Turboprops. BAe-146 5.1% Fokker 100 6% McDonnell Douglas DC-9-30 9.5% Fairchild FH-227 30% McDonnell Douglas DC-8 14% Canadair CL-44 Turboprop 46% Convair CV-580 Turboprop 22% Beechcraft, Fokker, McDonnell Douglass, Learjet, Fairchild, Aerospatiale, Canadair, Convair companies defunct. All Comets, including some Comet 1s, had full civilian use certification at some point after 1954, civilian use certification only being withdrawn after commercial flying stopped. Examples were flying until 1997 - one example did a signals research global circumnavigation flight series in 1993 via Australia virtually without a rest travelling 28000 miles, only had an ice warning indicator issue during the flights. *The DH Comet - World Firsts.* 1st gas turbine jet powered airliner. 1st high altitude 8psi pressurised full fuselage length passenger cabin airliner, not a trivial feature as structure strength required for pressurisation considerably exceeded strength required for normal flying stress. Nobody else had done anything similar before the Comet. The b-47 used 2 relatively small, heavily built pressurised modules (the aircraft where 6 had their wings fold up in 2 months while flying & some had their wings fall off while parked). The 1937 Boeing piston engined airliner pressurised passenger cabin was pressurised to 2 psi only - in fact that could easily be done as the normal unpressurized fuselage cabin structure strength for flying stresses only was all that was needed to be adequate so no significant weight increase issues needed addressing. 1st all hydraulically powered flying surface controls & actuators airliner with under carriage wheel disk brakes + ABS. 1st jet airliner to cross the Atlantic. 1st jet aircraft to do a world circumnavigation flights series. *Of course De Havilland had prior experience building many all metal construction airframe aircraft including thousands of jet powered fighter aircraft that were primarily of metal construction with pressurised cockpits & jet engines built by De-Havilland & we know the world's first all metal construction airframe airliner was built in England in the 1920s by Handley Page.* *_De Havilland did indeed always work to better than industry standards at the time, no evidence of negligence ever being produced in relation to the DH Comet._* The course of De Havilland & the general UK aerospace industry sector was not affected even slightly by the DH Comet. *_Other interesting World firsts_* _World's first turboprop aircraft._ *Vickers Viscount Turboprop Airliner 1947.* *A 1945 Gloster Meteor Aircraft with Turboprop Gas Turbine Engine.* They might like to answer these questions. *Which airline has just ordered* *60 RR England Trent XWB Engines* *& What aircraft are the engines for?* _Bonus question for 10 points._ Which country has the *World's Highest Combined Per Capita* *Nuclear + Defence + Aerospace Sector Activity?* 👍 Cheers 🙂 & 👍 & 🙂 & of course 😎 indeed. Cheers etc. _Toodle_ -PIP- *Old* *_Chap._* . .. . ... . .... . ..... ixcxicvcixvxivx . .... . .....,...... ... .. Ivcxcvcxcvcccvccvvv

No, no, no, no, noooo. You're wrong. It's always pilot error, or maybe, just sometimes, a bomb. Bombs are scary and stop people getting on the (money making machine) plane, not as scary though as the plane being bad and falling apart though. So remember, PILOT ERROR. OK?

The inlets were a fatal flaw

Bingo!

He's said a few times that the Disaster Scale is "mostly arbitrary" so I doubt there is a real process. I think he started using the Legacy Scale to differentiate between how horrifying a disaster is, and how much it actually changed things for the better.

It does, ridiculously sleek and well shaped! It makes some airliners look comically bulky by comparison.

@@skylined5534 I mean, I know high-bypass engines are much more efficient and having the nacelles detach from the wing is much safer. So on a rational level I know today's planes are better aircraft. But that doesn't change the fact that they look cumbersome.

The reason the skin was so thin was because de Havilland wanted to use their own engines instead of more powerful ones from Rolls Royce..

de Havilland simply lacked the technical experience in designing and building aircraft from riveted aluminum. The skins were far too thin and weak, there were too few fuselage reinforcement hoops and they were too weak, not enough rip-stop doubler joints the design and production techniques used in riveting was well below industry standards even for unpressurized aircraft. De Havilland recieved technical data on the B-29 pressurized cabins from Boeings during WW2 but engineers at de Havilland were still building aircraft from WOOD. De Havillands post-war jets wete made primarily from WOOD not riveted aluminum which was rhe industry standard.

@@TheJononator Rolls-Royce did not have a axial flow turbojet available when the Comet was designed.. Of course the placement of the engines was also another fatal flaw that caused several crashes. Based on an aerodynamic theory that later proved to be completely wrong, no other airliner ever copied the flawed engine placement of the Comet.

@@sandervanderkammen9230 A lot of fighters and bombers of the era did use a somewhat similar engine placement. But they had very different needs. The big revolution of Boeing and McDonald Douglas hanging the engines on underwing pylons was less an aerodynamic leap as it was one of serviceability and cabin noise comfort. The airlines loved it because it made servicing the engines much easier.

@@andrewtaylor940 Not true at all, while some supersonic fighters have their inlets in the Wing Root none have them in the actual leading edge causing a disruption of airflow to the engines at high angles of attack and reducing wing lift, in the case of the British V-bombers there are some subtle but important differences with placement of the inlets ahead and below the leading edge line of the wing that reduce the problem but were still based on the flawed theory and a lack of good wind tunnel data. Boeing engineer George Schairer was a member of the Von Karman Mission that discovered the Top Secret German _Luftfahrtforschungsantalt_ supersonic wind tunnel research lab in Braunschweig. Boeing stole or copied top secret data on jet engine placement and the plans for the P.1107 which became the B-47. The Boeing 707 Jet Stratoliner is directly based on the B-47 and the German wind tunnel data on jet engine placement.

Thank you!

Very true

Elizabeth, you have no conception of how loud it was. I secured a flight on one of the vintage 10A Electras operated by Trans Canada Airlines. In the cabin it was bad - you had to shout to be heard. In the cockpit, in-line with the props of the twin Wasp Junior radial engines, the word "deafening" was inadequate - at take-off power the pilot and co-pilot could not communicate with each other, no matter how loud they screamed. Remember, this is with modern headsets with microphones! They communicated with hand signals until they could pull back to cruising power. So, that was an easy dig, but it minimizes how wonderful modern air transport really is.

Haha,indeed.I'd rather deal with noisy props than screaming children and drunken passenger meltdowns nowadays.The British deserve particular credit for being so radically innovative.I realize they weren't as commercially successful as their American counterparts (who were indepted to De Havilland).The Brits produced some real beauties though,the Comet,VC 10,and Vanguard.And that was a great old movie.Marlene Dietrich was so intriguing.There's also a book on the topic by Neville Shute(sp) titled Airframe.He's the author of On The Beach as well.

@@BrainScramblies Hah,a plane crash would be quieter than some.

You haven't experienced real noise until you have flown a Shackleton with four Griffons on full throttle.😵

Pedantically souls can mean already dead.

@@waggyn Thats what I understood & offered the correction in a supportive way!!!