Moderators: jsumali2, richierich, ua900, PanAm_DC10, hOMSaR
rheinwaldner wrote:seahawk wrote:The 797 enjoys a 40 years technology advantage over the existing single aisle competition, it should be not depending on the container size to beat the competition with ease.
You forget, that it needs to be competitive against same-tech-level narrowbodies, that will arrive a few years later. Your argument is as flawed as Airbus saying in 2000: the A380 will enjoy 30 year technology advantage over existing VLA competition. And yes, it did beat the 744 and even the 748i with ease. But not the upcoming same-or more-tech-level near-VLA competition.
Would not a same-tech-level launch of a 200-250 seat mid-range NB in 2030 (be it from A or B) shorten the 797s competitive life so much, that the overall market outlook becomes questionable? In 2030 the 797 factories would just have reached the planned output rates.
uta999 wrote:The designs floating around for the 'new' 797 are so boring and safe.
Can't someone with an ounce of flair design something really radical, based around a completely new shape. Perhaps a Handley Page Victor shape, first flew in 1952, which looks more modern than anything being produced today. Designed nearly 70 years ago by a guy with a pencil.
Aircraft designers seem to have fallen into the Japanese car industry trap. Let's make all cars look the same!
https://en.wikipedia.org/wiki/Handley_Page_Victor
morrisond wrote:Would you then agree that the aircraft weights 10 x that of the fuselage?
Given that the barrel of the airplane is one of the lightest parts (isn't it something like 10% of the MTOW?)
morrisond wrote:or if you believe maths works both ways then a ~10% increase in fuselage weight would have to make the entire aircraft weight ~10% greater for a similar performance level.- even is there is a say a 10% disadvantage per seat - that overall is very marginal on the overall weight of the plane
morrisond wrote:. I would have to guess that the difference will purely come down to engines and whether or not they are half a gen or a full gen ahead which could be back ported to a 7w anyways.
A 6W or 5W would beat it (5W not over 200 seats) - but probably only if optimized for much shorter ranges with smaller wing/gear/etc. But then they are not competing in the same space and that is what the rewinged/shorter ranged NMA - A.K.A. NSA is for. (Pure speculation on my part).
Sorry for reviving the cross section debate - but I didn't bring it up.
ikolkyo wrote:uta999 wrote:The designs floating around for the 'new' 797 are so boring and safe.
Can't someone with an ounce of flair design something really radical, based around a completely new shape. Perhaps a Handley Page Victor shape, first flew in 1952, which looks more modern than anything being produced today. Designed nearly 70 years ago by a guy with a pencil.
Aircraft designers seem to have fallen into the Japanese car industry trap. Let's make all cars look the same!
https://en.wikipedia.org/wiki/Handley_Page_Victor
Funny how the first thing I see on that page is “fatigue cracks”. Come on now...
uta999 wrote:ikolkyo wrote:uta999 wrote:The designs floating around for the 'new' 797 are so boring and safe.
Can't someone with an ounce of flair design something really radical, based around a completely new shape. Perhaps a Handley Page Victor shape, first flew in 1952, which looks more modern than anything being produced today. Designed nearly 70 years ago by a guy with a pencil.
Aircraft designers seem to have fallen into the Japanese car industry trap. Let's make all cars look the same!
https://en.wikipedia.org/wiki/Handley_Page_Victor
Funny how the first thing I see on that page is “fatigue cracks”. Come on now...
It was never designed for the low-level sorties it ended up doing to avoid Soviet radar. In the end, the Victor flew until 1993 as an in-flight tanker with the RAF. The 787 had much the same start in life with some serious wing issues.
rheinwaldner wrote:seahawk wrote:The 797 enjoys a 40 years technology advantage over the existing single aisle competition, it should be not depending on the container size to beat the competition with ease.
You forget, that it needs to be competitive against same-tech-level narrowbodies, that will arrive a few years later. Your argument is as flawed as Airbus saying in 2000: the A380 will enjoy 30 year technology advantage over existing VLA competition. And yes, it did beat the 744 and even the 748i with ease. But not the upcoming same-or more-tech-level near-VLA competition.
Would not a same-tech-level launch of a 200-250 seat mid-range NB in 2030 (be it from A or B) shorten the 797s competitive life so much, that the overall market outlook becomes questionable? In 2030 the 797 factories would just have reached the planned output rates.
uta999 wrote:The designs floating around for the 'new' 797 are so boring and safe.
Can't someone with an ounce of flair design something really radical, based around a completely new shape. Perhaps a Handley Page Victor shape, first flew in 1952, which looks more modern than anything being produced today. Designed nearly 70 years ago by a guy with a pencil.
Aircraft designers seem to have fallen into the Japanese car industry trap. Let's make all cars look the same!
https://en.wikipedia.org/wiki/Handley_Page_Victor
flipdewaf wrote:morrisond wrote:Would you then agree that the aircraft weights 10 x that of the fuselage?
Given that the barrel of the airplane is one of the lightest parts (isn't it something like 10% of the MTOW?)morrisond wrote:or if you believe maths works both ways then a ~10% increase in fuselage weight would have to make the entire aircraft weight ~10% greater for a similar performance level.- even is there is a say a 10% disadvantage per seat - that overall is very marginal on the overall weight of the planemorrisond wrote:. I would have to guess that the difference will purely come down to engines and whether or not they are half a gen or a full gen ahead which could be back ported to a 7w anyways.
A 6W or 5W would beat it (5W not over 200 seats) - but probably only if optimized for much shorter ranges with smaller wing/gear/etc. But then they are not competing in the same space and that is what the rewinged/shorter ranged NMA - A.K.A. NSA is for. (Pure speculation on my part).
Sorry for reviving the cross section debate - but I didn't bring it up.
It comes down to the sweet spot for optimising hoop stresses for pressure, bending stresses for moment arms of the tail/engines/wings and then once you establish where that sweet spot lies then how you fit the relevant number of seats into that area.
Ovoid fuselage is a neat way to get through some of the issues but at a cost of a floor in tension which is a more complex and weight gaining scenario than for the standard for it being in tension.
All fun engineering challenges no doubt.
Fred
flipdewaf wrote:Ovoid fuselage is a neat way to get through some of the issues but at a cost of a floor in tension which is a more complex and weight gaining scenario than for the standard for it being in tension.
uta999 wrote:The designs floating around for the 'new' 797 are so boring and safe.
Can't someone with an ounce of flair design something really radical, based around a completely new shape. Perhaps a Handley Page Victor shape, first flew in 1952, which looks more modern than anything being produced today. Designed nearly 70 years ago by a guy with a pencil.
Aircraft designers seem to have fallen into the Japanese car industry trap. Let's make all cars look the same!
https://en.wikipedia.org/wiki/Handley_Page_Victor
bikerthai wrote:flipdewaf wrote:Ovoid fuselage is a neat way to get through some of the issues but at a cost of a floor in tension which is a more complex and weight gaining scenario than for the standard for it being in tension.
With all the draw-back of an ovoid fuselage, Boeing has to mature the design to it's final optimization as lessons learned from that work will surely help the development of a BWB aircraft.
bt
2175301 wrote:bikerthai wrote:flipdewaf wrote:Ovoid fuselage is a neat way to get through some of the issues but at a cost of a floor in tension which is a more complex and weight gaining scenario than for the standard for it being in tension.
With all the draw-back of an ovoid fuselage, Boeing has to mature the design to it's final optimization as lessons learned from that work will surely help the development of a BWB aircraft.
bt
The natural tendency of a horizontal ovid would be to put the floor in compression. I have no idea where the concept that the floor would be in tension came from. A vertical ovid would do that... but, that makes no sense unless it was going to be a double decked aircraft.
Have a great day,
2175301 wrote:bikerthai wrote:flipdewaf wrote:Ovoid fuselage is a neat way to get through some of the issues but at a cost of a floor in tension which is a more complex and weight gaining scenario than for the standard for it being in tension.
With all the draw-back of an ovoid fuselage, Boeing has to mature the design to it's final optimization as lessons learned from that work will surely help the development of a BWB aircraft.
bt
The natural tendency of a horizontal ovid would be to put the floor in compression. I have no idea where the concept that the floor would be in tension came from. A vertical ovid would do that... but, that makes no sense unless it was going to be a double decked aircraft.
Have a great day,
JayinKitsap wrote:United clamoring for the NMA also.
https://www.flightglobal.com/news/artic ... nt-456472/
If the NMA's capabilities are above the current NB's, there doesn't have to be full match on the costs, but yes it needs to be very capable as the alternate to do the route is a different WB with all of its extra weight to perform 7,000+ nm range.
Both Delta and United are in search of a replacement for the majority of their Boeing 757 and 767 fleets. The former operates 204 757s and 767s, and the latter 131 aircraft, Cirium's Fleets Analyzer shows
JayinKitsap wrote:United clamoring for the NMA also.
https://www.flightglobal.com/news/artic ... nt-456472/
ILNFlyer wrote:Looks like United wants Boeing to move things along with the aircrafts development.
Dennis [Muilenburg, chief executive of Boeing] and I talk about this all the time – speed up the process, we're growing, we need aircraft and they make great aircraft," Munoz told reporters on the sidelines of the US Chamber of Commerce Aviation summit on 7 March. "Having it in a little bit shorter timeframe would be helpful."
Munoz is mum on what United wants in the NMA, saying only that it will be a combination of fleet replacement and opening new markets. The airline has used the 787, Boeing's last cleansheet aircraft, to open numerous new markets, including nonstop flights to Singapore from the US mainland and service to the interior Chinese city of Chengdu.
"We want them to launch the right product," he says. "A lot of us have had a lot of input and conversation into what that might look like."
B1168 wrote:There is a substantial issue that Boeing will most definitely need to determine before all else——size. Will they attempt to use folding wing tips to squeeze 797s into a C parking spot, or will they go with a full D size plane? You see, lots of US airports have D parking spots, so that won’t be a problem there; but for Asian market, due to their newer age, they didn’t really need that many D parking spots, and letting a D size plane use a E parking spot will be a problem. What will Boeing choose for this?
Revelation wrote:B1168 wrote:There is a substantial issue that Boeing will most definitely need to determine before all else——size. Will they attempt to use folding wing tips to squeeze 797s into a C parking spot, or will they go with a full D size plane? You see, lots of US airports have D parking spots, so that won’t be a problem there; but for Asian market, due to their newer age, they didn’t really need that many D parking spots, and letting a D size plane use a E parking spot will be a problem. What will Boeing choose for this?
Very good question.
I don't know the answer, but hopefully we'll know the answer sooner than later.
Another question would be if they make folding wingtips, will they be an optional feature or will they be the default?
We see in 777x they made them the default but we know 777x wanted to fit into 777w gates and it flies relatively few legs per day compared to a 797 that might find itself banging out SYD-MEL-BNE triangle routes all day.
B1168 wrote:There is a substantial issue that Boeing will most definitely need to determine before all else——size. Will they attempt to use folding wing tips to squeeze 797s into a C parking spot, or will they go with a full D size plane? You see, lots of US airports have D parking spots, so that won’t be a problem there; but for Asian market, due to their newer age, they didn’t really need that many D parking spots, and letting a D size plane use a E parking spot will be a problem. What will Boeing choose for this?
BWIAirport wrote:B1168 wrote:There is a substantial issue that Boeing will most definitely need to determine before all else——size. Will they attempt to use folding wing tips to squeeze 797s into a C parking spot, or will they go with a full D size plane? You see, lots of US airports have D parking spots, so that won’t be a problem there; but for Asian market, due to their newer age, they didn’t really need that many D parking spots, and letting a D size plane use a E parking spot will be a problem. What will Boeing choose for this?
Probably not the airports' favorite option but couldn't some airports in question paint secondary lead-in lines (such as https://www.google.com/maps/@35.2199889 ... a=!3m1!1e3 ) to accommodate the larger aircraft?
SierraPacific wrote:I am sorry if this has been discussed in the previous 16 pages but will the flight deck be taken from the 787 and put into this aircraft? I know that this is all hearsay but having a common flight deck with the same suppliers could be a boost to the program.
B1168 wrote:There is a substantial issue that Boeing will most definitely need to determine before all else——size. Will they attempt to use folding wing tips to squeeze 797s into a C parking spot, or will they go with a full D size plane? You see, lots of US airports have D parking spots, so that won’t be a problem there; but for Asian market, due to their newer age, they didn’t really need that many D parking spots, and letting a D size plane use a E parking spot will be a problem. What will Boeing choose for this?
Turnhouse1 wrote:There are ways of doing it relatively simply. Heathrow T5 gates A13-17 are either 3 small or 2 medium gates https://www.google.com/maps/@51.4709096 ... a=!3m1!1e3 the gate area inside will likewise be shared between 2 or 3 gates so fewer busier gates shouldn't be too much of a problem. These will now be essentially A320 only since BA retired the last 767s though.
keesje wrote:Operating costs of the 757 have raised significantly over the last 5 years.
seahawk wrote:Turnhouse1 wrote:There are ways of doing it relatively simply. Heathrow T5 gates A13-17 are either 3 small or 2 medium gates https://www.google.com/maps/@51.4709096 ... a=!3m1!1e3 the gate area inside will likewise be shared between 2 or 3 gates so fewer busier gates shouldn't be too much of a problem. These will now be essentially A320 only since BA retired the last 767s though.
It is not that simple because you just lost an A320 gate if handling 2 797s which sucks in peak times.
SierraPacific wrote:I am sorry if this has been discussed in the previous 16 pages but will the flight deck be taken from the 787 and put into this aircraft? I know that this is all hearsay but having a common flight deck with the same suppliers could be a boost to the program.
bikerthai wrote:The other question is with the 737 MAX fall out, they will no doubt be facing financial issue the comming year. Will they bite the bullet and fund the new airplane? Or will they hold of until the situation stabilize?
bt
bikerthai wrote:SierraPacific wrote:I am sorry if this has been discussed in the previous 16 pages but will the flight deck be taken from the 787 and put into this aircraft? I know that this is all hearsay but having a common flight deck with the same suppliers could be a boost to the program.
Not too early to ask for anet.
Since this is a new aircraft, they have more free reign. But you can probably guess that Boeing will keep the design common, not only from a cost stand point, but to avoid additional development risk. They seem to like the dual panel configuration.
The other question is will they keep the yoke? My guess would be yes also for the small reason . . . reduce development risk.
bt
Weatherwatcher1 wrote:keesje wrote:Operating costs of the 757 have raised significantly over the last 5 years.
Are you referring to the Flight Length Sensitive Supplemental Inspections? How many airplanes have actually exceeded those limits? I wouldn’t think that many flying have hit those limits yet unless they are 1980s vintage airplanes.
mjoelnir wrote:seahawk wrote:Turnhouse1 wrote:There are ways of doing it relatively simply. Heathrow T5 gates A13-17 are either 3 small or 2 medium gates https://www.google.com/maps/@51.4709096 ... a=!3m1!1e3 the gate area inside will likewise be shared between 2 or 3 gates so fewer busier gates shouldn't be too much of a problem. These will now be essentially A320 only since BA retired the last 767s though.
It is not that simple because you just lost an A320 gate if handling 2 797s which sucks in peak times.
But you would need the added space anyway for the added passenger numbers.
mxaxai wrote:bikerthai wrote:The other question is with the 737 MAX fall out, they will no doubt be facing financial issue the comming year. Will they bite the bullet and fund the new airplane? Or will they hold of until the situation stabilize?
bt
IMHO they have to. Boeing currently has a time advantage over any Airbus response. Giving that away would be a strategic mistake. Boeing hesitated once with the NSA and the A320neo exploited that.
787 delivery is running well and the first 779 deliveries should start next year. On the military side, the KC-46 is finally being deliverd too. So medium term, cash flow should not be a problem. Short term, they might rather postpone some improvements of current models (if necessary).
keesje wrote:Weatherwatcher1 wrote:keesje wrote:Operating costs of the 757 have raised significantly over the last 5 years.
Are you referring to the Flight Length Sensitive Supplemental Inspections? How many airplanes have actually exceeded those limits? I wouldn’t think that many flying have hit those limits yet unless they are 1980s vintage airplanes.
I was referring to regular MRO. Engine and LDG costs have gone up. The companies supporting those are facing declining economies of scale for 757 specfic po arts and still want to maintain healthy margin. It gets harder to get price breaks, PMA's etc. As an operator you have no choice to get along with the rising cost levels. Switching service providers, parts manufacturers doesn't work anymore. Contrary, they try to stick to older contractual agreements while the supply chain tries to exit/ boosts pricing. There is no way back.
seahawk wrote:Turnhouse1 wrote:There are ways of doing it relatively simply. Heathrow T5 gates A13-17 are either 3 small or 2 medium gates https://www.google.com/maps/@51.4709096 ... a=!3m1!1e3 the gate area inside will likewise be shared between 2 or 3 gates so fewer busier gates shouldn't be too much of a problem. These will now be essentially A320 only since BA retired the last 767s though.
It is not that simple because you just lost an A320 gate if handling 2 797s which sucks in peak times.
bikerthai wrote:The other question is with the 737 MAX fall out, they will no doubt be facing financial issue the comming year. Will they bite the bullet and fund the new airplane? Or will they hold of until the situation stabilize?
bt
Turnhouse1 wrote:seahawk wrote:Turnhouse1 wrote:There are ways of doing it relatively simply. Heathrow T5 gates A13-17 are either 3 small or 2 medium gates https://www.google.com/maps/@51.4709096 ... a=!3m1!1e3 the gate area inside will likewise be shared between 2 or 3 gates so fewer busier gates shouldn't be too much of a problem. These will now be essentially A320 only since BA retired the last 767s though.
It is not that simple because you just lost an A320 gate if handling 2 797s which sucks in peak times.
By that logic no airline would ever operate a widebody, they take up more space but carry more passengers. The flexible setup requires no more airbridges than 3 A320 gates, and can be used as such if there are no 767/797s around, but gives extra flexibility.
morrisond wrote:flipdewaf wrote:morrisond wrote:Would you then agree that the aircraft weights 10 x that of the fuselage?
Given that the barrel of the airplane is one of the lightest parts (isn't it something like 10% of the MTOW?)morrisond wrote:or if you believe maths works both ways then a ~10% increase in fuselage weight would have to make the entire aircraft weight ~10% greater for a similar performance level.- even is there is a say a 10% disadvantage per seat - that overall is very marginal on the overall weight of the planemorrisond wrote:. I would have to guess that the difference will purely come down to engines and whether or not they are half a gen or a full gen ahead which could be back ported to a 7w anyways.
A 6W or 5W would beat it (5W not over 200 seats) - but probably only if optimized for much shorter ranges with smaller wing/gear/etc. But then they are not competing in the same space and that is what the rewinged/shorter ranged NMA - A.K.A. NSA is for. (Pure speculation on my part).
Sorry for reviving the cross section debate - but I didn't bring it up.
It comes down to the sweet spot for optimising hoop stresses for pressure, bending stresses for moment arms of the tail/engines/wings and then once you establish where that sweet spot lies then how you fit the relevant number of seats into that area.
Ovoid fuselage is a neat way to get through some of the issues but at a cost of a floor in tension which is a more complex and weight gaining scenario than for the standard for it being in tension.
All fun engineering challenges no doubt.
Fred
I didn't say it would be 10% more per seat - I'm guessing that when you average it - it could be better. However yes if at the outside it was 10% heavier per seat that would have knock on effects - if you designed for the exact same performance.
This is a serious question - One of the rumors from a while back was that the Fuselage was not an Oval per say but two circles of Different diameters - The top of the fuselage down to the Floorbeams 1/2 of a circle the width of the fuselage and the bottom 1/3 of a larger circle.
Wouldn't it be a lot easier to keep the floor in tension with this approach?
seahawk wrote:But that was not the wide oval expected to be used on 787. The form of double bubble design is quite standard.
morrisond wrote:[list=][/list]seahawk wrote:But that was not the wide oval expected to be used on 787. The form of double bubble design is quite standard.
The concept of half of a smaller circle on top of 1/3 of a bigger circle on bottom that I referenced above would lead to fuselage that was wider than high - Horizontal Ovalishy..