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Originally Posted by Rainier
(Post 11164680)
The 757-300 was a victim of timing in nothing else. The line was shut down immediately after industry contraction from the 9/11 attacks and was also the victim of the merged Boeing-McDonnell Douglas management that focused on Return On Net Assets, which made the Renton factory floor appear expensive. I have been told by those in the know that airlines came back to Boeing after the 757 line had been shut down requesting to purchase more, but by then the decision had been made.
The 757-300 for a long time had the best single-aisle economics, which is why Delta/Northwest used them to replace the DC-10s on their Hawaiian routes, which are the most price competitive in the US. One can see why airlines are asking for a new airplane to fill this niche. Looking back certainly, the continued low fuel prices also played a part in 757-300 orders as it permitted more fuel-inefficient airplanes to continue operating rather than be replaced. The problem with a 757-300-type replacement is whether the size of the market is sufficient to develop an entire new platform and new engine. With 737Max and A320Neo families offering trans-continental capability, the market for a slightly larger airframe with marginally more range might not be sufficient to drive the per unit costs down low enough to take market share from 737Max/A320Neo airplanes to make the business case work. Rather than use a 757-300 replacement, airlines might just use more frequent 737/A320 flights on the shorter segment to fill the need rather than pay higher acquisition costs for a more fuel efficient narrow body. |
For ground handling, narrow bodies win. Especially LCC/charter ops on bucket and spade routes. Above wing I can see how a twin aisle is more attractive. However, below wing it needs to be something that can be bulk loaded quickly and easily. Thinking of UK regional bases and greek islands with seasonal staffing and limited capacity the last thing you want to be doing is messing about with ULD's and high loaders. This is the big difference between the 75/76.
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Bulk loading baggage surely is a 1950’s idea that won’t be repeated? Containerised baggage was one of the advantages of the 320 over the 737 cited by my airline when they made their recent future fleet order. ULDs aren’t expensive compared to worker injury compensation.
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If pax loading/unloading was performed closer to the middle of the fuselage, say at the first emergency exit, rather than at the very front, then people entering the plane could split into two, moving forward and aft thereby potentially halving the number of people blocking the aisles (depending on the forward/aft split ratio). On the 757 300 there seems to be enough gangway access at the first emergency exit. Perhaps this practice is already routine, I have always boarded at the very front.
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Perhaps this practice is already routine, I have always boarded at the very front. |
Originally Posted by tdracer
(Post 11164302)
Baring a massive improvement in battery energy density vs. weight (I'm talking an order of magnitude), electric aircraft will never be viable for trips of more than a few hundred miles.
In a combustion engine the heavier oxidiser comes free with the air and you exhaust the even heavier combustion products H2O and CO2. Assume to carry the oxidiser with you like in a rocket and in addition carry all exhaust products. Thats what a battery does in essence. You will wind up with Saturn 5 type weight to payload ratios. Battery weight with 0,4kWh/kg top notch lithium batteries for a 100T Kerosene equivalent is 3200T, which is about a fueled Saturn 5. It is probably more realistic if you need electric long range transport to go ballistic with a rail gun Jules Verne style... |
N.b. the A321 left 'ahead-of-the-wing' emergency exit is in fact a full size boarding door. Same as the other 4, different from the other 3.
Leisure operators don't use containers due to logistics challenges and lack of equipment. Those only makes sens for a specific mission and operation profile which is out of reach for most airlines. The turn-around times should not be yield critical on a 4500 NM sector proposed. Even if, the most time consuming is the availability of cleaning teams (late arrival, missing supplies and insufficient numbers) which is why the successful ULCC try to get away without them. On a short (below 2 hrs) sector with a reduced and pay-to-consume catering model this is possible. 9 hrs sector I don't think so, also the cleaning needs to be somewhat deeper than intra-EU experience normally requires. I mean to say that for the proposed airliner pax, bags and cargo manipulation does not seem to be the limiting element. Regulatory stick time is (one of them). Whether you can make 7 + 8 hours legs in one day with 3+8 crew, assuming normal complement 2+5. Unfortunately EU has broken that barrier already, US and China not yet AFAIK. So expect the newly proposed ship to have a full bunk. |
The 757 disappeared from the catalogue because, quite simply, airlines stopped buying it. Notably it had always been sold as a short haul aircraft, there were very few who used it straight from the factory for longer runs, and those (never that many) later used Transatlantic were actually hand-me-downs from domestic services.
That is where most of the demand for this size aircraft traditionally was. It was even unusual for it to appear on US transcontinental nonstops, despite having the range, until the end of its production. By then the A321 was established, and the bulk of the demand for aircraft of this size, especially outside the USA, had moved over. It's also notable how even those operators of the earlier A321s from the 1990s stopped buying them after a while and went back to the A320. The demand by established carriers for aircraft of this size was hit by the rise of the LCCs, which scooped a good proportion of demand by duplicating their routes. Surprising was the way that BA sold off their large pioneering 757 fleet in the early 2000s, and replaced them with A319s, a fraction of the capacity. |
Over the years, at least from 2015 the NMA seemed set to be a small wide body, 2-3-2 cross section.
A wider single aisle could benefit from a big more comfort medium term , specially with 1,5 aisle width, so passengers can pass each other / trolleys during flight and deboarding. I never saw Airbus or Boeing proposing this however. :suspect: The Russians have a wider MS21, The biggest version -400 will be longer than the A321. https://cimg0.ibsrv.net/gimg/pprune....58c6c351ca.jpg |
Originally Posted by WHBM
(Post 11170871)
The 757 disappeared from the catalogue because, quite simply, airlines stopped buying it. Notably it had always been sold as a short haul aircraft, there were very few who used it straight from the factory for longer runs, and those (never that many) later used Transatlantic were actually hand-me-downs from domestic services.
As far as long range, it's pretty telling that for the PW2000/757, 37k and 40k ratings were available but it was mainly the freight operators that sprung for the 40k - passenger operators staying with the 37k. When we did the Pratt powered 757-300, we offered a 43k rating but it wasn't bought - I'm not sure it was even certified. It's also rather telling that in spite of very good operating costs, no body bought the -300 aside from the launch customers. |
Which begs the question if any airline actually wants
what the article research found. It could be just a list of holes that are not covered but nobody will purchase anyway. Which are the killer 3800-4500 NM city pairs? |
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Originally Posted by keesje
(Post 11170918)
Over the years, at least from 2015 the NMA seemed set to be a small wide body, 2-3-2 cross section.
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Originally Posted by procede
(Post 11171042)
With a narrowbody, the fuselage would be so long, it would mean a heavy structure to counteract the bending and also very high and/or complex main gear to not have a tail strike on takeoff and landing and still get to an appropriate angle of attack. Going to 2-3-2, like the 767, you are adding a aisle for a single extra chair per row. Aisles do no generate revenue, but do add volume (drag) and weight, making the aircraft increasing the cost per seat.
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Originally Posted by procede
(Post 11171042)
With a narrowbody, the fuselage would be so long, it would mean a heavy structure to counteract the bending and also very high and/or complex main gear to not have a tail strike on takeoff and landing and still get to an appropriate angle of attack. Going to 2-3-2, like the 767, you are adding a aisle for a single extra chair per row. Aisles do no generate revenue, but do add volume (drag) and weight, making the aircraft increasing the cost per seat.
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Originally Posted by procede
(Post 11171042)
With a narrowbody, the fuselage would be so long, it would mean a heavy structure to counteract the bending and also very high and/or complex main gear to not have a tail strike on takeoff and landing and still get to an appropriate angle of attack. Going to 2-3-2, like the 767, you are adding a aisle for a single extra chair per row. Aisles do no generate revenue, but do add volume (drag) and weight, making the aircraft increasing the cost per seat.
Originally Posted by oceancrosser
(Post 11171757)
The 757-300 and the DC8-61/63 called, they beg to differ on the single aisle length. Pretty similar length both of them.
Because Boeing now knows these disadvantages of the 757/737 fuselage. They can avoid / reduce them, if they know it will be a 35+ rows aircraft for longer flights. The biggest variant of the Russian (if ever build) MS21-400 is going to be a 757 class aircraft, nearly 2m longer than an A321. https://cimg4.ibsrv.net/gimg/pprune....014e959a1d.gif |
"A bigger cross-section to improve weight" ?
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The A321 is 185-230.
https://en.wikipedia.org/wiki/Airbus...jet%20versions. Given that will Airbus waste money on a 250 seat variant? |
Originally Posted by Chris2303
(Post 11171875)
The A321 is 185-230.
Given that will Airbus waste money on a 250 seat variant? |
Originally Posted by Chris2303
(Post 11171875)
The A321 is 185-230.
https://en.wikipedia.org/wiki/Airbus...jet%20versions. Given that will Airbus waste money on a 250 seat variant? |
Originally Posted by DaveReidUK
(Post 11171862)
"A bigger cross-section to improve weight" ?
It becomes extremely long and bending moments around the middle of the fuselage require lots of material (additional weight) to keep it stiff and strong enough. That also become a factor when 2-3 or 3-3 cross section are stretched real far. https://cimg2.ibsrv.net/gimg/pprune....cc10a19359.jpg https://www.aircharter.com.hk/aircra.../boeing757-300 |
Originally Posted by tdracer
(Post 11170968)
The 737NG really killed demand for the 757. Aside from long range, a 737-900 could do most of what a 757-200 could with lower operating costs and it cost a lot less to build than a 757, so Boeing could sell it much cheaper. When the production rate of the 757 got down to 1 or 2 per month, the factory space needed became a killer - in short Boeing could make far more money by devoting that factory space to another 737 line and increasing the 737 production rate.
As far as long range, it's pretty telling that for the PW2000/757, 37k and 40k ratings were available but it was mainly the freight operators that sprung for the 40k - passenger operators staying with the 37k. When we did the Pratt powered 757-300, we offered a 43k rating but it wasn't bought - I'm not sure it was even certified. It's also rather telling that in spite of very good operating costs, no body bought the -300 aside from the launch customers. |
Originally Posted by Rwy in Sight
(Post 11180337)
An updated 757. Would history for the model and Boeing would have been different if there was a serious update on the 757 was offered instead of shutting down the line - engines plus electronics?
There was a plan to use the updated (777 based) flight deck and avionics from the 767-400ER on the entire 757 and 767 line (the lack of FADEC on the RB211-535 being a stumbling block), but when the 767-400ER flopped and with demand for the 757 rapidly falling that plan was abandoned. Pratt did some major upgrades to the PW2000 engine around the year 2000 (we called it 'the Y2K package') that improved the fuel burn by (IIRC) a couple percent. Granted not as much as they could have gotten with an all-new engine but that would have cost a fortune. In short, at the time the 757 line was shut down, the demand for its capabilities hadn't developed yet. Even today, I question if there is sufficient demand for such capabilities (in excess of that provided by existing narrowbodies) to justify an all new aircraft. |
In short, at the time the 757 line was shut down, the demand for its capabilities hadn't developed yet. Even today, I question if there is sufficient demand for such capabilities (in excess of that provided by existing narrowbodies) to justify an all new aircraft. Mostly for short-medium <5hr flights. Apart from that, it slowly seems to sink in that the MAX isn't doing fine for the rest of the decade & something lean /modern is needed.. The MoM/NMA concepts have been shrinking since it's inception. Naming it a "Boeing 737 Replacement" is still a no go though. |
The smartest Boeing move would be to go from like MAX 8 size to above the A321neo size and cover everything up to 787 size. This might require two pairs of wings.
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Originally Posted by Less Hair
(Post 11189469)
The smartest Boeing move would be to go from like MAX 8 size to above the A321neo size and cover everything up to 787 size. This might require two pairs of wings.
My biggest concern would be 120-180 seats <1500NM. That's the bulk (80+% ?) of the all NB flights globally. You don't want to have severely reduced competition there.. https://cimg6.ibsrv.net/gimg/pprune....fc58af2cdb.jpg Possible 150-170 seats lean A220 variant |
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