de Havilland Comet would not have been successful anyway?
- Thread starter SactoMan101
- Start date
I think in the end, the biggest issue with the original DH 106 Comet I was the fact de Havilland engineers pushed the limit of a thinner skin for the fuselage and wings of the plane just a tad too for the the technology of its day, not to mention the issue of improper riveting that cause earlier metal fatigue of the skin than anticipated, especially when the Comet flew at altitudes far above that of contemporary piston-engined airliners in the early 1950's. As such, Boeing learned from de Havilland's failure of engineering and made sure the 707's structure was less susceptible to early metal fatigue issues caused by repeated flights above 30,000 feet altitude.
But let's say de Havilland knew of the dangers of metal fatigue of repeated flying to and from over 30,000 feet cruising altitude and designed the skin structure and windows properly. It would have enjoyed more success, but the limitations of the Comet design--especially with the engines buried in the wing roots, instead of the podded installation pioneered by the B-47--would have limited the growth potential of the basic design to effectively what became the Comet 4 of 1957. And the Comet 4's passenger/cargo capacity, speed and range would still be inferior to the Boeing 707-320 Intercontinental that arrived in 1960.
(By the way, one wonders what would have happened had the Vicker V1000 actually been fully developed and powered by Rolls-Royce Conway turbofans? Would it have mean not only a true 707-320B competitor, but we would have never seen the VC10 with its tail-mounted engines?)
But let's say de Havilland knew of the dangers of metal fatigue of repeated flying to and from over 30,000 feet cruising altitude and designed the skin structure and windows properly. It would have enjoyed more success, but the limitations of the Comet design--especially with the engines buried in the wing roots, instead of the podded installation pioneered by the B-47--would have limited the growth potential of the basic design to effectively what became the Comet 4 of 1957. And the Comet 4's passenger/cargo capacity, speed and range would still be inferior to the Boeing 707-320 Intercontinental that arrived in 1960.
(By the way, one wonders what would have happened had the Vicker V1000 actually been fully developed and powered by Rolls-Royce Conway turbofans? Would it have mean not only a true 707-320B competitor, but we would have never seen the VC10 with its tail-mounted engines?)
No civilian aircraft is ever at its maximum popularity just a couple of years after entering service, which is when the Comet crashes happened. Also, since it was the Comet I that crashed, and they came out with the Comet IV more than 4 years later, I suspect it wasn't quite as limited as it might have been otherwise, though I agree the design had its limits.
However, like the comet, those accidents lost it the confidence of the public.
Podded engines also provide a structural advantage by spacing the weight of the engines over a greater span and reducing bending moments on the wing spar roots.
Propeller-driven transports an bombers did that to provide clearance between all the propellers. Apparently early (multi-engine) jet designers did not understand the concept and had to re-learn how distribute the load of engines and fuel
along the entire wing-span.
The Avro Jetliner was not much better (structurally) than the Comet. It's dual engine pods were only slightly outboard of the main undercarriage.
In the end, Boeing, MD, Airbus etc. all learned from their predecessors' mistakes.
Propeller-driven transports an bombers did that to provide clearance between all the propellers. Apparently early (multi-engine) jet designers did not understand the concept and had to re-learn how distribute the load of engines and fuel
along the entire wing-span.
The Avro Jetliner was not much better (structurally) than the Comet. It's dual engine pods were only slightly outboard of the main undercarriage.
In the end, Boeing, MD, Airbus etc. all learned from their predecessors' mistakes.
Depends on the particular locale I think. TEAL/Air New Zealand used Electras for 13 years quite happily and they weren't the only ones (QANTAS and Ansett among others). I've never heard of any confidence problems from the travelling NZ public about the type. Admittedly they did leave one in pieces on the runway at Whenuapai in 1965, but that was a training flight (no passengers) and not the aircraft's fault.
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Which is where I have a problem - they went for the lightest structure they thought they could get away with, in a situation where they had next to no empirical data. That sets off all sorts of alarm bells in me as an engineer - particularly as they did their proof testing to confirm that it worked OK in service with live passengers!
Hardly a surprise - it's a 10 years older aircraft design!
Not sure - the VC-10 had a lot in common with the VC-7 (V-1000). It may well still have existed as a development of the VC-7, or the next model along.
That I really, really doubt - it's very simple structural engineering indeed. Remember that wing structure is only one of the things being considered - engine out performance for instance is another major one, and there putting the engines as close as possible to the centreline is a bit requirement. In the very early days of jet aviation when they were far less reliable than today and the available thrust was marginal, that had to be a major factor.
Staying in service longer, and all orders being fulfilled are both good, with maybe also more fulfilled contracts later.
Ultimately, I think the first two crashes were economically survivavble for the aircraft (one was blamed on issues other than the aircraft), but that third one, after De Havilland, under government pressure, okayed them to continue flying, that was what ultimately killed the Comet as a major seller.
Ultimately, I think the first two crashes were economically survivavble for the aircraft (one was blamed on issues other than the aircraft), but that third one, after De Havilland, under government pressure, okayed them to continue flying, that was what ultimately killed the Comet as a major seller.
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Well they already had the Comet 1A in service, were working on the slightly enlarged longer ranger Comet 2 in 1953 and had the enlarged Comet 3 test flying in mid-1954 so obviously quickly realised the need to grow it. If we say it takes a year to get it into production and service that gives de Havilland a window of two and a half years before the Boeing 707 has its first test flight. Pan Am and Eastern Airlines were apparently interested in the Comet, if de Havilland can deliver them an enlarged version soon enough to be seen to crack the US market and before waiting for Boeing is a viable option do people think an extra fifty to a hundred planes sold would be completely unbelievable?
Just to be pedantic; the B36 reference was to the long runways it needed not to the wings or indeed the aeroplane itself at all.
I must be pedantic too, because that's how I read it as well.
The closest competitor to the 707 was the DC8. In the beginning, sales were very close. But Donald didn't want to change the fuselage, and sales dropped off. Then the super 60 series was produced and sales returned. Then came noise abatement. Then came the CFM-56. Times change, and aircraft have to change to suit the client and the times. All the while with an eye on cost per passenger seat/mile, different capacity, seat configuration and range have to suit the airline, and manufacturers have to "adjust". The Comet VII series 200 might have been the variant that turned things around...or not.
By a more successful Comet, we mean major defects being corrected early in the process, then hundreds of Comets being sold, then follow-up designs selling by the thousands until deHavilland could compete directly with Boeing, MD, Airbus, etc. If deHavilland were truly successful, Airbus might never get off the ground. In the perfect alternate timeline, deHavilland would currently build four or five different sizes of jet airliners to serve different routes.
More likely BAE as I can't see de Havilland managing to stay independent up to modern times, the financial and government pressures to merge would just be too great. I think they could maybe have sold 200-250, maybe 300 at the most, before they reached the maximum they could do with the design and had to start afresh. The various British aviation companies did have a wide range of models and ideas that could have covered the market if things had been handled somewhat better.
For commercial aircraft in an ideal, everything goes absolutely perfect, avoiding all the stupid mistakes timeline I say things would generally go
- BOAC find out about the shortcuts de Havilland are taking and demand that they switch to Rolls-Royce Avon engines, this adds six months extra to the launch date but allows for the slightly enlarged longer range version to be the initial launch version
- With the great success and no crashes the Comet 2 is quickly launched with improved engines and the fuselage stretched an extra 15 feet, our timeline's Comet 3/4, later improved models begin the first trans-Atlantic jet flights via Gander
- With a larger eye towards foreign sales the Air Ministry steps in and stops the RAF from demanding too many military-specific modifications for the V-1000 with Vickers decided to go with podded engines, when the RAF pulls out the government grants launch aid and the Ministry sits on BOAC when they start making noises, the VC-7 launches at roughly the same time as the Boeing 707 with comparable performance
- With their large African and Asian routes a modified version with a T-tail and the engine pods moved to the rear plus slightly re-designed wing is introduced as the VC-10
- Taking the success with the Comet de Havilland stick to their guns with their DH.121 Trident design when BEA starts getting jittery over a small drop in air passenger numbers, appeals to the Air Ministry see them side with de Havilland and the Trident launches at the same time as the Boeing 727 being a match for any of the American planes of the period
- The BAC One-Eleven is launched and enjoys the success it did in our timeline, from previous experience BEA dithering isn't allowed to stand in the way of the improved stretched 500 version that builds upon its success in the US to be a competitor to the Boeing 737
- This success sees the BAC Two-Eleven and Three-Eleven developments go ahead to compete with the Boeing 727-200 variants
- In 1965 when BEA puts out their specification for an 'Airbus' Hawker Siddeley as the parent company of de Havilland modify their Trident design as the HS.134 by extending the fuselage, moving the engines to the wings and changing them to turbofans, switch to low mounted tail but keep the same nose - essentially what Boeing did with the 727 to create the 757 15 years later, the HS.134 steals a march and is wildly successful
- A variant of the HS.134 looks like a good fit for the Airbus A300 and developments to steal a march on both it and the later Boeing 767, the UK could go it alone or if they join the European Airbus consortium it puts them in a much stronger position likely to take the lead on the project
- The major hole in their inventory is going to be the 747 and I'm not sure there'd be a driver for a British one before Boeing makes the move, BAC will be too busy with Concorde but I could see Hawker Siddeley potentially having a go at developing a reply to the 747 perhaps as a joint-venture with a contribution from BAC presaging the merger to become British Aerospace later on
- An alternative could be a European consortium to build a 747 competitor and develop future Airbus variants
But like I said this is the 'the Gods smiles upon them' scenario.
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I can just see it now: de Havilland gets what is essentially the Comet 4 into service by early 1957, especially with orders from Pan Am and American Airlines. Can you imagine American Airlines chairman Cyrus Rowlett "C.R." Smith beaming a big smile for newsreel cameras as the Comet started non-stop jet service between New York City and Los Angeles circa February 1957? And watched United Air Lines lose a lot of business on this transcontinental route?
And watched United Air Lines lose a lot of business on this transcontinental route?It wouldn't be non-stop, the Comet 4 just like the early Boeing 707s and Douglas DC-8s needed to go via Gander in Canada when travelling westwards due to the prevailing headwinds IIRC. The 707 didn't have the range to make the journey in one go until the stretched 707-320 variant came into service in mid-1959.
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SactoMan101 was talking about NYC-LAX, not NYC-LHR, which even early jets could do in one hop.
In the OTL, the Comet 4 in BOAC service could fly from New York to London eastbound non-stop, but westbound flights had to stop in Gander to refuel. It wasn't until the 707-320B and 707-420 that the 707 could fly from London to New York non-stop westbound on a year-round basis.