UltraFan
I never understood why Boeing, with all its enormous profits, needed $500mil from the engine supplier.
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A family of aircraft with as far as possible commonality, so that a pilot could go from smallest to largest with ease. Flight decks and handling characteristics as similar as possible along with the rest of the systems, SOPs and operational philosophy.
A single aisle 190 seater B787. The current B787 with the 8,9,10 versions is well placed. The new B777X once sorted out will cover the top end of the market. Whilst there will be places for niche aircraft such as supersonic, VLA and middle of the market, why bother ? |
Originally Posted by krismiler
(Post 10657463)
Whilst there will be places for niche aircraft such as supersonic, VLA and middle of the market, why bother ?
That's a heck of a 'niche'. Fully agree about supersonic and VLA though. |
Previously there was a huge gap between the B737-200 and the B747-200 into which the B757/767 was neatly slotted.Now with greater capacity, longer range narrow bodies and much smaller wide bodies that gap has narrowed considerably.
Many airlines needed something between the 73 and 74 but many of those would now choose either a B737-900 or a B787-800. Only a few would specifically require something in the middle, however if the growth in air travel is sufficient it could pull the number up to a viable total. With the MAX debacle necessitating a new narrow body sooner, rather than later and ongoing problems with the B787 and B777W Boeing won’t have the resources to take on another new project for a number of years, leaving Airbus A321 variants virtually unchallenged in this area. |
Are the economics really worth a narrowbody clean sheet design using composites ?
I would have thought a new Boeing product range based on the 787 design would be the way to go Then I looked up the empty weight on the 787-9, it’s very similar to the much older three engine DC10 This was a big surprise, I thought the main reason to build with composites is to save weight and that just doesn’t appear to be the case with the 787 It seems most of the efficiency comes from the advanced engines, systems and wing I imagine an all new composite design could be ‘over built’ less and have a lower empty weight but it makes you wonder whether it’s worth it |
Originally Posted by tdracer
(Post 10657199)
They did stretch the 757 - the 757-300. You may not be familiar with it because it was a big flop (55 built - 5% of total 757 production). The main problem with the 757 is that it was relatively expensive to build - when the 737NG came along it cost little more than half as much, and aside from long range it could do pretty much anything the 757-200 could.
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Originally Posted by stilton
(Post 10659752)
Are the economics really worth a narrowbody clean sheet design using composites ?
I would have thought a new Boeing product range based on the 787 design would be the way to go Then I looked up the empty weight on the 787-9, it’s very similar to the much older three engine DC10 This was a big surprise, I thought the main reason to build with composites is to save weight and that just doesn’t appear to be the case with the 787 It seems most of the efficiency comes from the advanced engines, systems and wing I imagine an all new composite design could be ‘over built’ less and have a lower empty weight but it makes you wonder whether it’s worth it |
The A320 vs B727 was a good example of how efficiency improved over 25 years. Basically the A320 does the same job with one fewer engine, one fewer flight crew member and uses half the fuel.
With the basic A320 being 30 years old now, I wonder if a brand new design would offer similar improvements, given that engine and flight crew numbers couldn’t be reduced. |
Originally Posted by BRE
(Post 10659768)
That is interesting. Why was the 757 such much more expensive to build? Didn't it use the same fuselage cross section that the 707, 727, 737 all shared? If it really was that much more expensive to build, wouldn't that have been true of the A310 and A320 also?
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Originally Posted by krismiler
(Post 10657711)
Previously there was a huge gap between the B737-200 and the B747-200 into which the B757/767 was neatly slotted.Now with greater capacity, longer range narrow bodies and much smaller wide bodies that gap has narrowed considerably.
Many airlines needed something between the 73 and 74 but many of those would now choose either a B737-900 or a B787-800. Only a few would specifically require something in the middle, however if the growth in air travel is sufficient it could pull the number up to a viable total. With the MAX debacle necessitating a new narrow body sooner, rather than later and ongoing problems with the B787 and B777W Boeing won’t have the resources to take on another new project for a number of years, leaving Airbus A321 variants virtually unchallenged in this area. There are a lot of 757s and 767s out there that are getting quite long in the tooth, and the A321 NEO simply isn't a good replacement. It's single aisle and it's wing is too small - to make the A321LR viable they loose cargo capability which is often a bigger money maker than the SLF. |
Fuselage length also becomes a problem as well, increased length needs increased ground clearance or tail strikes become a greater risk. Some smaller airports even have difficulty with the A321 on the apron as the tail sticks out too far.
Hopefully Airbus won’t repeat Boeing’s mistake and try to take the A320 beyond the current range, any more than an A321XLR needs to be an all new design. |
Originally Posted by BRE
(Post 10659770)
That is very surprising, especially as the MDs had a reputation of being built like tanks.
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Originally Posted by glob99
(Post 10660614)
The 787-9 is 12000 Kg lighter than the DC-10. That seems a significant weight savings.
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Originally Posted by glob99
(Post 10660614)
The 787-9 is 12000 Kg lighter than the DC-10. That seems a significant weight savings.
Not sure where you get those numbers, I’ve seen empty weights of 254000lbs for the DC10-30 and 244000lbs for the 787-9, only a 10k lb difference And surprising |
Originally Posted by tdracer
(Post 10660508)
When the 757 was originally designed (1978-1981), it was expected that the cost of jet fuel would skyrocket over the next 20 years (the number I remember was $10/gallon by 2000, which of course didn't happen). So, pretty much every design trade of lower weight vs. lower cost fell on the side of lower weight. Further, the 757 tooling was designed for a max production rate of 7/month (one very 3 work days). By contrast, by 2000 they were cranking out 737s at over 1/day. This gave considerable economies of scale to the 737 and much lower overhead costs per aircraft. Eventually as customers chose the 737 over the 757, and the production rate dropped on the 757, the overhead costs associated with keeping the 757 line open became too high (especially since that same factory space could be devoted to manufacture of additional highly profitable 737s).
So how does the 757 compare to the A32x in weight and fuel consumption? Propably apples and oranges because of size and range differences. Did the 767 see the same optimization for weight? AFAIR, it does not compare favorably even to early A330. |
Basic weight of a B747-400 177,400 kg
Basic weight of a A340-600 179,200 kg A full B747-400 from London to Orlando has same operating costs of an A330. Bring on the B747-900 with B787 technology. |
Originally Posted by B744IRE
(Post 10661076)
Basic weight of a B747-400 177,400 kg
Basic weight of a A340-600 179,200 kg A full B747-400 from London to Orlando has same operating costs of an A330. Bring on the B747-900 with B787 technology. Page 4-8 has the 2013 costs per hour. 300+ passenger jet cost was $14,600/hr, <300 was $9,100/hr. Four engine jets cost per hour was $14,000, two engine jets were $10,300 per hour. https://www.faa.gov/regulations_poli...4-op-costs.pdf |
Originally Posted by Fogliner
(Post 10656561)
What was the main problem with Boeing working to stretch and tweak the 757 platform?
I always liked the look of them and with the higher stance wouldn't they be a better starting point for modern engines than the old 737? fog
Originally Posted by B744IRE
(Post 10661076)
Basic weight of a B747-400 177,400 kg
Basic weight of a A340-600 179,200 kg A full B747-400 from London to Orlando has same operating costs of an A330. Bring on the B747-900 with B787 technology. |
Originally Posted by B744IRE
(Post 10661076)
Basic weight of a B747-400 177,400 kg
Basic weight of a A340-600 179,200 kg A full B747-400 from London to Orlando has same operating costs of an A330. Bring on the B747-900 with B787 technology. |
Originally Posted by BRE
(Post 10660849)
Thanks for the insight! I had suspected overhead but not realized weight savings were prioritized in the design. I suppose overhead does not make that much of a difference once development and invest for tooling is written off.
So how does the 757 compare to the A32x in weight and fuel consumption? Propably apples and oranges because of size and range differences. Did the 767 see the same optimization for weight? AFAIR, it does not compare favorably even to early A330. It's not really fair to compare the 767 with the A330 - the A330 came along over 10 years after the 767 and hence the more direct 767 comparisons would be with the A310 and A300-600. |
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