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In Defence Of The DH Comet

Mon Jun 19, 2000 11:31 am

In the 'Why I'm Pissed Off With Boeing' thread, a few people argued against European aviation competence by bringing up the de Havilland Comet and writing it off as a flop.

The truth is that it was ten years ahead of anything else (first flight 1949) and orders were pouring in, including Pan Am and every flag carrier around the world. Even in the short time the Comet 1 flew before being grounded (52-53), it was delivered to Air France, Canadian Pacific and UAT (later known as UTA) as well as BOAC. The aircraft opened regular jet service to Singapore and Johannesburg (and many points en route). De Havilland in fact pushed the envelope beyond what was known (metal fatigue was not even known about) and the aircraft showed a fatal flaw in that the skin was too thin and the square window corners proved to be the achilles heel for the type.

However, in the subsequent crash investigations, de Havilland and the British Air Crash Bureau (AIB) wrote the book on metal fatigue and gave all the data they had to Boeing, Douglas and the US Gov't. The research proved invaluable, and while Boeing must have come to a few conclusions of their own with the B47 et al, it was the Comet that defined modern jet transport, represented the biggest leap forward for commercial aviation (more so even than Concorde) and the airways were made safe.

Maybe not a huge commercial success (although the Comet 4 went on to be a highly profitable and long lived program) but probably the most important step in the development for the world's air transport industry.
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Good Point

Mon Jun 19, 2000 11:40 am

Very good point. Much was learned about structural fatigue from the Comet. The reason for all crashes of the Comet was because of stress in a corner of one of the square windows. Oval windows do not have this weakness, and today square windows are not used on any commercial jet aircraft.
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RE: In Defence Of The DH Comet

Mon Jun 19, 2000 11:47 am

Just to add about the Comet's initial success, Air France used the type to all it's African and Mideast colonies and Canadian Pacific were about to start Vancouver - Sydney jet ops...in 1952! Six years before Pan Am got the 707 into service, and even the 707 was beaten across the Atlantic by the (now with round windows) Comet 4 (the Comet 1 didn't have trans-Atlantic range...in fact neither did the Comet 4 and 707-120, both had to make westbound refuelling stops).

And I made a mistake, the Comet 1 served for two years, 52-54, not 52-53.
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British Jets

Mon Jun 19, 2000 12:02 pm

Speaking as a staunch Yank...

...all that you said, and more, are true; but for the Comet's tragic flaws, the Brits might well own the airliner market. The failures that they suffered were, as has been observed, without precedent, and could as easily have happened to any other manufacturer which might have tried to extend the parameters of aircraft design thusly.

Not to mention the fundamental work on early jet engine technology, thanks to Whittle.

A final thought: there are few aircraft as clasically clean and beautiful as the Comet; its appearance remains fresh today. I had the god fortune to look at one up very close on the tarmac in Mexico City. Quite a treat!
...three miles from BRONS, clear for the ILS one five approach...
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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 1:11 am

I agree with all posts. Considering what the rest of the world was flying (and driving!), the Comet was positively something out of the future. An antique now, her lines are as graceful as ever. The Comet paid a heavy price for being the trendsetter it was, as Boeing, Douglas, Convair, Vickers, and Tupolev all learned a great deal about high-altitude jet design and safety from the Comet.

I was very sad to read of the fate of the former Mexicana Comet that languished at O'Hare (a heroic effort to restore the plane ran out of time and funds, and the plane had to be scrapped). Thankfully, one Comet in the US escaped the scrapper's torch and is beautifully preserved in Seattle.

The Comet will always hold a special place in the heart of this airliner fan.
The aeroplane has unveiled for us the true face of the earth. -Antoine de Saint-Exupery
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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 9:04 am

I just found an old picture in my house that was taken in 1963, that shows my aunt and grandmother about to board a Mexicana Comet bound to Los Angeles.

It turns out that Pan Am originally ordered 4 Comet's. This was just as a precautionary method just in case something would have gone wrong with the early 707's.
Well, as history showed, the 707's proved to be great workhorses and the Comet's were never operated by Pan Am. Instead, Pan Am transfered them down to it's Mexican subsidiary Mexicana de Aviacion. If you look closely at this picture, you can see that Mexicana's livery resembles that of Pan American World Airways 1950's livery.

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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 12:41 pm

The Comet lived on long after it's early demise in the form of the "Nimrod" ASW aircraft.

So....it really wasn't a bad design after all.

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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 12:49 pm

This could possibly be one of the best strings that I have ever read. Very thoughtful and informative by all parties.

While the comet (especially the nose) looks like something out of Buck Rogers, it could still pass for something futuristic. I think that's the same reason that I like the Caravelle so much (as well as the DHC-8Q and Challenger/CRJ).
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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 12:52 pm

I have had the great pleasure of flying in a several Comet 4C's of -who else- my former employer Dan-Air Services. I rode in the cockpit on most of these trips...absolute magic.
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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 12:53 pm

Actually the early Caravelles, through the -3 model I believe actually used the same nose as the Comet. Unfortunately aircraft like the Comet and Caravelle were ill-timed. They were great advancements for jet passenger aircraft, but came too early. That has been one of the problems with European aircraft, until Airbus came along. They had groundbreaking designs, but the timing was off.
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Comets In Rcaf Service

Tue Jun 20, 2000 5:19 pm

Hi! I'm here too to defend the Comet. The plane was very good and very reliable, don't forget that even when the tragic crashes started there was one Air Force that kept the plane flying, that was RCAF, they ordered 2 units and eventually flew it until I guess 1965 without having any problem, so that gives me the sense that the plane was good and did it's task. I wounder if anyone have more information regarding these Comets in RCAF service?
Please let me know!
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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 7:49 pm

My opinion is quite simple. Since it was the first jet to be planned in mass production there is always the possibilty of fatal errors. But at the end, even other manufacturer have learned from the weakpoints the Comet 1 had and this helped also to shape the first generation of commercial jets.

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RE: In Defence Of The DH Comet

Tue Jun 20, 2000 9:08 pm

Something else about the Comet I like is the cockpit is like a WW2 bomber, with all that quilted padding / insulation. The early crews even wore those leather flying helmet things with the headphones built in. It only takes one look at that insulation to remember that when it first flew, it was only four years after Lancasters were bombing Germany - and those Lancs were state of the art, F117s of their time. I wish I'd had a ride in a Comet. God bless those engineers and test pilots who had the imagination and ingenuity to build such a plane, with no money, in a burnt out shell of a country that was bankrupt from war - rationing lasted a good eight years after it's first flight! Not too shabby a job they did in such harsh conditions.
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RE: In Defence Of The DH Comet

Wed Jun 21, 2000 1:12 am

Well I agree with you on the fact that a lot was learned from the Comet, I do dissagree with one of you rstatements..."The truth is that it was ten years ahead of anything else (first flight 1949)" Well not exactly...actually the Avro Jetliner was ready before the Commet, and it's firt flight was delayed exactly 14 days after the first flight of the Comet, because the British Government did not want to be showed up by a Colony. This plane was much more suited to the needs of many airlines in Europe and North America...because it was perfectly suited for short flights that were much more popular back then.....The program was also hindered when RR refused to provide the engines for the plane, and AVRo had to go with a heavier 4 engined version as opposed to the TWO engined original design. This is when TCA now Air Canada pulled out of the program..but TWA and other US airlines expressed great interest in the airplane and planned to order it, just be fore it was cancelled in favour of Jet fighter production. But before it was cancelled it did manage to be operate the first International Jet mail transport from Toronto to New York........Had the British government not interfeared and hindered the prograss of the Canadian design we may have had an industry equal to or larger then the Boeing market......the plane would have been a great success and it was proven that it did not suffer from the metal problem the the Comet had......
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RE: In Defence Of The DH Comet

Wed Jun 21, 2000 1:57 am

I think it is fair to say that the Comet came very early on in the development of new technologies at the time, and as such it was rapidly outdated by the 707's, DC-8's, VC-10's and others, but that doesn't change the fact that it was on the very leading edge of a wave of development of jet aircraft.

I also give the Comet a lot of respect for the simple fact that after the cause of the accidents were found, the information was shared with the entire world to prevent another such tragedy, even though it helped other manufacturers outdo deHavilland. In fact, modern ideas of fatigue testing, design of pressurized fuselages, and even crash analysis were largely thanks to the Comet. It was a tragic cause to have to develop these sciences, but simply for these reasons the flawed Comet I tragedies did not happen in vain, and its legacy lives on in the form of safer jetliners from all manufacturers.

I do, however, believe that perhaps saying "the Comet was too far advanced for its time" is a bit of a euphemism for the mistakes DH made. There was some knowledge of fatigue, although not a lot. Reading the accident report it clearly states that although DH made the mistakes through a lack of knowledge at the time, it also notes that they should have made more use of the tools at their disposal such as strain guages, and that static and fatigue test airframes would have to be separate in order to prevent a static test from causing strain hardening.
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RE: Slawko

Wed Jun 21, 2000 2:30 am

Slawko, You are 100% correct;

While the Comet was a groundbreaking design, the Avro Canada C102 Jetliner was, in theory, just as advanced and, in some respects, more advanced than the deHavilland Comet.

Whatever its reason for flying later than the Comet, the reason it was cancelled was because of the Korean War. The Canadian Govt. decided that it was better to concentrate on the C110 jet fighter.

The actual range of the C102 was seven hundred miles greater than the initial DH-106 Comet 1, at 2,500nm compared to the Comet's 1,700nm.

For all that, the lessons learned from the D.H.106 proved invaluable for both the European and United States aircraft industries.


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RE: In Defence Of The DH Comet

Wed Jun 21, 2000 2:39 am

I must confess, I was aware of the Canadian JetLiner when I initially wrote this post, but I didn't want to blur the issue. I agree that the C102 could have turned out at the same time as the Comet and would have been a (probably) better aircraft - range, payload etc. But at the end of the day the Canadians dropped the ball by not getting it into service. At least BOAC, dH and the British had the nerve to go all the way - next thing you know, Cox's Bazaar in Bangladesh has jet flights (along with about thirty or more other cities, and many not served by jets for another 20 years, Cox's being one example). Shame about the C102, wonder how that would have worked out?
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RE: In Defence Of The DH Comet

Wed Jun 21, 2000 8:39 am

I'm in the process of reading Bill Gunston's book "Plane Speaking" and he has some interesting cooments on the Comet. He makes the same point as AC183 does on this thread - that metal fatigue was not completely unknown at the time, it was just that methods of testing for and monitoring for fatigue were poorly understood. As a result, airliners tended to be over-engineered, how many DC-3's or Ju52's have fallen foul of metal fatigue? De Havillands, according to Gunston, often had an arrogant atitude and were reluctant to take on board information they had not obtained directly themselves. Don't forget Vickers were designing the Viscount at the same time as the Comet and they were very concerned about the affects of pressurisation and depressurisation on the fuselage structure. That is why they designed the Viscount with oval windows (and in the case of the prototypes and Series 700, oval doors too). Vickers had built pressurised Spitfires and Wellingtons during the war so they did know a thing or two about the subject. I don't think De Havilland had ever designed a pressurised 'plane before the Comet (correct me if I'm wrong). Incidentally, Fokker also chose oval windows for the F-27. The use of square windows (and square ADF panels) was a major design oversight by De Havilland - even in the light of knowledge available at the time.

I have mentioned elsewhere about the visit of some Boeing engineers to Hatfield when the Comet 1's were in production. They could not believe the small scale of the whole operation - it was almost at a cottage industry level by their standards. Basically, they reported back to Bill Allen that De Havilland would be no threat to Boeing if and when Boeing decided to build a jet transport. I think the fight for jetliner supremacy was going to be won by the US, irrespective of what De Havilland, Sud Aviation or any other European manufacturers thought. It's only now(almost fifty years on) that Airbus, who can match Boeing in the scale of their operation, can truly challenge American domination of the world airliner market.
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RE: In Defence Of The DH Comet - Trident

Wed Jun 21, 2000 10:59 pm

Whilst not disputing the facts I would point out the DC3 & Ju52 are not pressurised. It was the pressuisation cycles that accelerated the metal fatigue.

As to the small scale production of a/c in the UK, one has to bear that we are talking about just after the war. Due to the threat of bombing, a/c production was dispersed to lots of small factories. This way the Germans could not wipe out a whole a/c production line as would have been possible had there been large factories. The Americans did not have this threat so could build huge production lines.

Additionally I believe there was an agreement made during the war between the Americans & British that the U.S. would concentrate on building transport a/c (were they thinking ahead to post war) while the British would concentrate on military a/c.

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RE: In Defence Of The DH Comet

Thu Jun 22, 2000 11:07 am

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