VV wrote:

moa999 wrote:

VV wrote:

Exactly.
If one doesn't know one should not write numbers.

If you're going to question someone else's numbers you need some detail.
Otherwise you just sounds like a 14yo kid in a schoolyard argument.

That is fine for me.
I really do not need anyone to believe me on this specific topic.

That's just as well. I clicked on the links you provided and you appear to have done similar model for the 77W as I have done for multiple aircraft. I'm not sure how "world famous" it is but we'll leave that to the individual to decide.

The first point of call is this.

Under what basis is the calculator "modified". There appears to be a change in the OWE to the 407klb and a change in "efficiency factor" to 1.15, is this efficiency factor basically a fuel specific range modifier? if so why 15% higher?
I also note that you appear to show the Zero Fuel weight as OWE + number of pax*225lb. You don't appear to have any consideration for catering (water, towels, food beverages, bedding) ca be several tons on a long haul flight.

Secondly,

You calculator appears to show that even as it stands it puts a route of 9184nm (basically nil wind SYD-LHR) at 200pax which is fine (as that corresponds to what the Boeing figures give) but is not the expectation of the route requirements, it is believed to be 9500nm (there is a Leeham article that points to this).

If you think my Breguet derived equation or my assumptions are wrong above please let me know and we can have a discussion.

Fred

keesje wrote:

I can see QF call it a day and ordering a fleet of off the shelf A350LR and -1000s.

If QF goes down the A path.

I can't see more than an initial order for 8-10 aircraft, just enough to operate SYD/MEL-LHR and SYD-JFK.

Plus maybe 20-25 options.
10 for replacement 350neoLR aircraft when that's launched, with the initial order cascaded to 333 replacements.
And remainder for possible 380 replacement with a further stretch.

For the same reason if they went the B path,
I actually think they'd prefer the 777-9X over the 772LR, as it's also a better A380 replacement

Wow all this fuss for a 10 plane order. I guess it sets up the subsequent long haul fleet order but really, what a kerfuffle.QF waited forever to decide to not go for a 300 seat long hauler. Now it's taking forever to decide which one to take to make up for the past mistake.

I dunno. It all seems a little like QF believing it's own hype. Surely A and B salesteams have more fruitful targets elsewhere. If this was Qatar, you'd all be bleating about AAB being a tool. But Qantas gets this never ending pass because... well I'm guessing a big western centric blindspot.

moa999 wrote:

keesje wrote:

I can see QF call it a day and ordering a fleet of off the shelf A350LR and -1000s.

If QF goes down the A path.

I can't see more than an initial order for 8-10 aircraft, just enough to operate SYD/MEL-LHR and SYD-JFK.

Plus maybe 20-25 options.
10 for replacement 350neoLR aircraft when that's launched, with the initial order cascaded to 333 replacements.
And remainder for possible 380 replacement with a further stretch.

For the same reason if they went the B path,
I actually think they'd prefer the 777-9X over the 772LR, as it's also a better A380 replacement

I think for Qantas the ULR Sunrise business case, is not even half the story.

Heaving an efficient ~350 seat long haul aircraft to expand in Asia and TransPac is the bigger priority.

Up to 300 seats is well covered by the 787/A330 fleet.

Replacing 747s by 787-9 surrenders capacity/ devaluates slots in a growing, highly competitive market.

If Qantas ignores buying big efficient twins, they still will soon have A350s all over the place, with the wrong tails.

The distant, end destination location of SYD and MEL, makes big twins very suitable.

2023, potential A350 operated flights into SYD and MEL: http://www.gcmap.com/mapui?P=ist-syd%2C ... wls2&DU=nm


https://twitter.com/frenchpainter

majano wrote:

I am struggling to see why the discussion has gone back to aircraft capabilities when the latest news is that Qantas has

1. Negotiation
2. Negotiation (also not sure where 30% comes from or is comparative to. Pilots can't work 30% more hours, and obviously $s for Sunrise will be less than A380 and probably 747)
3. Always was going to be required
4. Always going to be some premium, though 30% sounds high, but possibly achievable if you simply don't offer discount fares and have a slight premium on the flexible.

Sparker wrote:

timh4000 wrote:

Regardless of you guys math peeing contest, QF will have it figured out. Their choice of plane(s) will have fuel burn that will give them a profit.

I find their "test flights " are some would be or maybe really is ingenious.

These flights that they are considering... makes them look super duper concerned about the customer. Not that they don't, except they are tacking about an hour to the current longest scheduled flights. By And, there about a half dozen planes that have the capability. Soo... there are already people who are willing to fly 18 or 19 hours in y class. Personally, I'm not getting on a plane that's pushing 20hrs flight time without it being a apt/resident set up, like what Etihad has. That's just me,

Anyway people will still choose the cheap seats.... tacking on another hr isn't going to make any real difference. Same goes for the pilots who will be getting 4 rostered. AND the FA'S will have their typical complement and will know how to manage their rest time as well.

So, what are these test flights really trying to accomplish?

Regulatory approval. CASA will not approve 20 hour flights (with TOD pushing 22 hours) based on QF asserting that it's safe, because it is 'only' an hour or two longer than any other RPT flight in the world.

They require QF to do detailed fatigue modelling, based on established fatigue science and QF's own operations, and then validate that real-world flying produces the results that the model predicts.

This regulatory approach isn't unique to airline fatigue safety. Other fatigue regulated industries (long haul trucking, for example) have similar approval processes for shifts that push the accepted boundaries.

And, similar approaches are used in aircraft manufacturing - much of the testing done on new planes is to validate the models developed by the OEMs.

Of course, QF is *also* using the test flights as a great marketing tool. Two birds, one stone, and all that.

Just so I'm understanding correctly, the "test flights" were not done voluntarily they were required due to 20+hr operations?

keesje wrote:

If Qantas ignores buying big efficient twins, they still will soon have A350s all over the place, with the wrong tails.

Well they had that same issue when they ignored buying big efficient twins (777-300ER) and there were 777-300ERs all over the place with the wrong tails, and yet they survived somehow.

If these ultra long haul nonstop flights prove successful in passenger numbers, can we see Boeing reviving their Sonic Cruiser project or Airbus coming with a faster jet that could do these ultra long haul flights in much less time, economically?

A388

A388 wrote:

If these ultra long haul nonstop flights prove successful in passenger numbers, can we see Boeing reviving their Sonic Cruiser project or Airbus coming with a faster jet that could do these ultra long haul flights in much less time, economically?

Speed and economy in aviation are generally mutually exclusive things.

I'm sad there is no path forward for project sunrise. If this is tweaking work rules and aircraft pricing could make it happen, that would be good news. But I suspect the base economics are too close to call.

I hope to be proven wrong.

Lightsaber

scbriml wrote:

moa999 wrote:

2. Negotiation (also not sure where 30% comes from or is comparative to. Pilots can't work 30% more hours, and obviously $s for Sunrise will be less than A380 and probably 747)

The requirement for a 30% improvement in crew productivity came from Qantas themselves.

https://www.smh.com.au/business/compani ... 53c02.html

The airline says it also needs pilots to agree to a pay deal that would deliver "productivity improvements" of about 30 per cent, which are currently under negotiation.

It all depends on how they define productivity. If it’s on a RPK/RTK basis these flights would be in excess of 30% increase.

zeke wrote:

Sparker wrote:

Regulatory approval. CASA will not approve 20 hour flights (with TOD pushing 22 hours) based on QF asserting that it's safe, because it is 'only' an hour or two longer than any other RPT flight in the world.

This is not new science, and it is not QF doing the research, it is the university of Adelaide and the Sydney universities. Some operators have had full CAO 48 exemptions via fatigue management systems for 20 years.

The data they use to validate the models not only covers aviation, they have looked at long range bus drivers, truck drives, and train drivers in Australia. The fatigue modelling is also now used by first responders to measure their fatigue levels

A number of operators in Australia have no limit on the maximum duty times, operators like coastwatch and some rfds sections already operate under fatigue management systems rather than the CAO 48 limits.

Having a fatigue risk management system doesn't automatically allow unlimited duty times (and I'm skeptical that any operator would have such approval). Qantas have an FRMS but it still has capped duty times at I believe 18 hours, so not long enough for Project Sunrise flights. The CAO 48.1 instrument authorizing an FRMS effectively requires changes to the system need to be backed by science.

Also, the universities are conducting the research on behalf of Qantas, it's sort of splitting hairs to say QF isn't the ones doing it.

benjjk wrote:

zeke wrote:

Sparker wrote:

Regulatory approval. CASA will not approve 20 hour flights (with TOD pushing 22 hours) based on QF asserting that it's safe, because it is 'only' an hour or two longer than any other RPT flight in the world.

This is not new science, and it is not QF doing the research, it is the university of Adelaide and the Sydney universities. Some operators have had full CAO 48 exemptions via fatigue management systems for 20 years.

The data they use to validate the models not only covers aviation, they have looked at long range bus drivers, truck drives, and train drivers in Australia. The fatigue modelling is also now used by first responders to measure their fatigue levels

A number of operators in Australia have no limit on the maximum duty times, operators like coastwatch and some rfds sections already operate under fatigue management systems rather than the CAO 48 limits.

Having a fatigue risk management system doesn't automatically allow unlimited duty times (and I'm skeptical that any operator would have such approval). Qantas have an FRMS but it still has capped duty times at I believe 18 hours, so not long enough for Project Sunrise flights. The CAO 48.1 instrument authorizing an FRMS effectively requires changes to the system need to be backed by science.

Also, the universities are conducting the research on behalf of Qantas, it's sort of splitting hairs to say QF isn't the ones doing it.

The capped duty times is where the 30% improvement for productivity will come in. Without the extra 30% duty time QF won't be able to operate the flights they want. The Unions and QF will play some hard ball, but more than likely they'll come to agreements, no doubt with sweeteners and concessions from all parties involved.

timh4000 wrote:

Sparker wrote:

timh4000 wrote:

Regardless of you guys math peeing contest, QF will have it figured out. Their choice of plane(s) will have fuel burn that will give them a profit.

I find their "test flights " are some would be or maybe really is ingenious.

These flights that they are considering... makes them look super duper concerned about the customer. Not that they don't, except they are tacking about an hour to the current longest scheduled flights. By And, there about a half dozen planes that have the capability. Soo... there are already people who are willing to fly 18 or 19 hours in y class. Personally, I'm not getting on a plane that's pushing 20hrs flight time without it being a apt/resident set up, like what Etihad has. That's just me,

Anyway people will still choose the cheap seats.... tacking on another hr isn't going to make any real difference. Same goes for the pilots who will be getting 4 rostered. AND the FA'S will have their typical complement and will know how to manage their rest time as well.

So, what are these test flights really trying to accomplish?

Regulatory approval. CASA will not approve 20 hour flights (with TOD pushing 22 hours) based on QF asserting that it's safe, because it is 'only' an hour or two longer than any other RPT flight in the world.

They require QF to do detailed fatigue modelling, based on established fatigue science and QF's own operations, and then validate that real-world flying produces the results that the model predicts.

This regulatory approach isn't unique to airline fatigue safety. Other fatigue regulated industries (long haul trucking, for example) have similar approval processes for shifts that push the accepted boundaries.

And, similar approaches are used in aircraft manufacturing - much of the testing done on new planes is to validate the models developed by the OEMs.

Of course, QF is *also* using the test flights as a great marketing tool. Two birds, one stone, and all that.

Just so I'm understanding correctly, the "test flights" were not done voluntarily they were required due to 20+hr operations?

The test flights were not necessarily required. Changes to the fatigue system need to be supported by science, to the satisfaction of CASA. Qantas probably could have validated that science on the ground (or with SQ cooperation) if they really wanted to but that would require a longer, complicated process to try and simulate a flight. There comes a point where it's just easier to fly the thing to get maximum accuracy for little effort. Particularly when the extra cost on top of delivery is minor and the publicity gain tremendous.

While Qantas are publicly saying they need a 30% productivity concession, given how union negotiations work that is probably are high-ball number. They say one thing, the union will demand something like a pay rise, seven day rest period and a free kitten, and the two sides agree somewhere in the middle.

benjjk wrote:

Having a fatigue risk management system doesn't automatically allow unlimited duty times (and I'm skeptical that any operator would have such approval).

It does if you have the CAO exemption, the hard limits are in the CAO, FRMS has variable limits.

benjjk wrote:

Qantas have an FRMS but it still has capped duty times at I believe 18 hours, so not long enough for Project Sunrise flights.

You can have an FRMS without the CAO 48 exemption

benjjk wrote:

The CAO 48.1 instrument authorizing an FRMS effectively requires changes to the system need to be backed by science.

You sure about that ? Where is the FRMS mentioned here ?

https://www.casa.gov.au/file/186846/dow ... n=kMnvCVde

benjjk wrote:

Also, the universities are conducting the research on behalf of Qantas, it's sort of splitting hairs to say QF isn't the ones doing it.

Not splitting hairs at all, the research is conducted by the university, they own the results and technology. For example FAID is a commercialisation of the SA university research.

benjjk wrote:

Qantas probably could have validated that science on the ground (or with SQ cooperation) if they really wanted to but that would require a longer, complicated process to try and simulate a flight.

Not sure why SQ would cooperate with QF given that they are competitors on the LHR-SYD route and PS would directly threaten their SYD-SIN-LHR loads.

Also not sure how valid fatigue studies carried out on a 789 would be given they have different “in-cabin” conditions (moister air IIRC). Can someone in the know advise how significant this would be on the outcome?

zeke wrote:

benjjk wrote:

Having a fatigue risk management system doesn't automatically allow unlimited duty times (and I'm skeptical that any operator would have such approval).

It does if you have the CAO exemption, the hard limits are in the CAO, FRMS has variable limits.

benjjk wrote:

Qantas have an FRMS but it still has capped duty times at I believe 18 hours, so not long enough for Project Sunrise flights.

You can have an FRMS without the CAO 48 exemption

benjjk wrote:

The CAO 48.1 instrument authorizing an FRMS effectively requires changes to the system need to be backed by science.

You sure about that ? Where is the FRMS mentioned here ?

https://www.casa.gov.au/file/186846/dow ... n=kMnvCVde

benjjk wrote:

Also, the universities are conducting the research on behalf of Qantas, it's sort of splitting hairs to say QF isn't the ones doing it.

Not splitting hairs at all, the research is conducted by the university, they own the results and technology. For example FAID is a commercialisation of the SA university research.

Yep, a big benefit of an FRMS is to allow for flexible duty times appropriate for the specific operation, but it still needs to specify upper limits. Qantas absolutely do operate under an FRMS since about the start of the year, at least one of the unions was very much against it, however it still does not have a provision for more than 18 hours.

The instrument detailing general requirements of an FRMS can be found here: https://www.legislation.gov.au/Details/F2019C00842 - appendix 7 is the relevant one covering FRMS. The first requirement for its operating procedures is that the FRMS must incorporate scientific principles and knowledge.

flipdewaf wrote:

VV wrote:

moa999 wrote:

If you're going to question someone else's numbers you need some detail.
Otherwise you just sounds like a 14yo kid in a schoolyard argument.

That is fine for me.
I really do not need anyone to believe me on this specific topic.

That's just as well. I clicked on the links you provided and you appear to have done similar model for the 77W as I have done for multiple aircraft. I'm not sure how "world famous" it is but we'll leave that to the individual to decide.

The first point of call is this.

Under what basis is the calculator "modified". There appears to be a change in the OWE to the 407klb and a change in "efficiency factor" to 1.15, is this efficiency factor basically a fuel specific range modifier? if so why 15% higher?
I also note that you appear to show the Zero Fuel weight as OWE + number of pax*225lb. You don't appear to have any consideration for catering (water, towels, food beverages, bedding) ca be several tons on a long haul flight.

Secondly,

You calculator appears to show that even as it stands it puts a route of 9184nm (basically nil wind SYD-LHR) at 200pax which is fine (as that corresponds to what the Boeing figures give) but is not the expectation of the route requirements, it is believed to be 9500nm (there is a Leeham article that points to this).

If you think my Breguet derived equation or my assumptions are wrong above please let me know and we can have a discussion.

Fred

I have been banned for some time because I said, "Try again".

Now, it is obvious for me that you made some assumptions that do not necessarily reflect the reality of the operation. When going to Europe, despite the headwind and so on you can very easily carry more than 200 passengers at 225 lb per passenger if you apply usual reclearance/redispatch trick. Basically instead of the normal 5% contingency fuel you can reduce it to a number as low as 1%.

I did a very conservative approach with a relatively heavy OEW and 2% or contingency fuel. If the actual redispatch at HEL is done properly, the contingency fuel can even go down lower and you can carry about 260 passengers.

For simplicity I built the case in the picture below. If you want to see the reasoning, it is written in the blog. You can search for "four weeks to Christmas".

VV wrote:

flipdewaf wrote:

VV wrote:

That is fine for me.
I really do not need anyone to believe me on this specific topic.

That's just as well. I clicked on the links you provided and you appear to have done similar model for the 77W as I have done for multiple aircraft. I'm not sure how "world famous" it is but we'll leave that to the individual to decide.

The first point of call is this.

Under what basis is the calculator "modified". There appears to be a change in the OWE to the 407klb and a change in "efficiency factor" to 1.15, is this efficiency factor basically a fuel specific range modifier? if so why 15% higher?
I also note that you appear to show the Zero Fuel weight as OWE + number of pax*225lb. You don't appear to have any consideration for catering (water, towels, food beverages, bedding) ca be several tons on a long haul flight.

Secondly,

You calculator appears to show that even as it stands it puts a route of 9184nm (basically nil wind SYD-LHR) at 200pax which is fine (as that corresponds to what the Boeing figures give) but is not the expectation of the route requirements, it is believed to be 9500nm (there is a Leeham article that points to this).

If you think my Breguet derived equation or my assumptions are wrong above please let me know and we can have a discussion.

Fred

I have been banned for some time because I said, "Try again".

Now, it is obvious for me that you made some assumptions that do not necessarily reflect the reality of the operation. When going to Europe, despite the headwind and so on you can very easily carry more than 200 passengers at 225 lb per passenger if you apply usual reclearance/redispatch trick. Basically instead of the normal 5% contingency fuel you can reduce it to a number as low as 1%.

I did a very conservative approach with a relatively heavy OEW and 2% or contingency fuel. If the actual redispatch at HEL is done properly, the contingency fuel can even go down lower and you can carry about 260 passengers.

For simplicity I built the case in the picture below. If you want to see the reasoning, it is written in the blog. You can search for "four weeks to Christmas".

What program did you use for this?

jman wrote:

VV wrote:

... ...

I have been banned for some time because I said, "Try again".

Now, it is obvious for me that you made some assumptions that do not necessarily reflect the reality of the operation. When going to Europe, despite the headwind and so on you can very easily carry more than 200 passengers at 225 lb per passenger if you apply usual reclearance/redispatch trick. Basically instead of the normal 5% contingency fuel you can reduce it to a number as low as 1%.

I did a very conservative approach with a relatively heavy OEW and 2% or contingency fuel. If the actual redispatch at HEL is done properly, the contingency fuel can even go down lower and you can carry about 260 passengers.

For simplicity I built the case in the picture below. If you want to see the reasoning, it is written in the blog. You can search for "four weeks to Christmas".

What program did you use for this?

It is a very short program I wrote many years ago to replicate 777-300ER's ZFW-range diagram published in the Aircraft characteristics for airport planning document. I published the code in 2010 in my blog. Unfortunately I cannot provide the link here because it would be considered as "self-promotion".

It was written with an idea to estimate the 777-9 and 777-8 that I knew would have similar MTOW than that of the 777-300ER and with lower take-off thrust requirement.

So it helps me a lot to understand the 777-9 and -8's payload-range capability.

The most important thing is NOT the program I use, but the numbers it generates for 777-9 and 777-8. So far, it looks like the results coming from the simple program are coherent despite the protest coming from Fred "flipdewaf".

I even think it still gives me the most coherent numbers I have seen in many places on the internet so far.

jman wrote:

...
What program did you use for this?

If you want the code, please send me a private message.

This month we will know what Qantas would decide.

In the next three weeks they need to say something.

VV wrote:

jman wrote:

...
What program did you use for this?

If you want the code, please send me a private message.

i messaged you thanks

VV wrote:

flipdewaf wrote:

VV wrote:

That is fine for me.
I really do not need anyone to believe me on this specific topic.

That's just as well. I clicked on the links you provided and you appear to have done similar model for the 77W as I have done for multiple aircraft. I'm not sure how "world famous" it is but we'll leave that to the individual to decide.

The first point of call is this.

Under what basis is the calculator "modified". There appears to be a change in the OWE to the 407klb and a change in "efficiency factor" to 1.15, is this efficiency factor basically a fuel specific range modifier? if so why 15% higher?
I also note that you appear to show the Zero Fuel weight as OWE + number of pax*225lb. You don't appear to have any consideration for catering (water, towels, food beverages, bedding) ca be several tons on a long haul flight.

Secondly,

You calculator appears to show that even as it stands it puts a route of 9184nm (basically nil wind SYD-LHR) at 200pax which is fine (as that corresponds to what the Boeing figures give) but is not the expectation of the route requirements, it is believed to be 9500nm (there is a Leeham article that points to this).

If you think my Breguet derived equation or my assumptions are wrong above please let me know and we can have a discussion.

Fred

I have been banned for some time because I said, "Try again".

Now, it is obvious for me that you made some assumptions that do not necessarily reflect the reality of the operation. When going to Europe, despite the headwind and so on you can very easily carry more than 200 passengers at 225 lb per passenger if you apply usual reclearance/redispatch trick.

This isnt how QF operate their long haul flights, they plan with 70mins holding available over the destination, they no longer use the redispatch trick...

VV wrote:

Basically instead of the normal 5% contingency fuel you can reduce it to a number as low as 1%.

I did a very conservative approach with a relatively heavy OEW and 2% or contingency fuel. If the actual redispatch at HEL is done properly, the contingency fuel can even go down lower and you can carry about 260 passengers.

For simplicity I built the case in the picture below. If you want to see the reasoning, it is written in the blog. You can search for "four weeks to Christmas".

Well I read through your blog post and you have done nothing but build a model out of the acaps payload range information and assumed that it uses conservative numbers and then use that to build a model for the aircraft payload range then bastardised it to be what you think a 779X could be and assumed tighter fuel loads. Your 200 lines of code with a pretty interface appears to be worth about 8cells suitably labeled and suitable functions inserted.

The Boeing ACAPS data and tables appear to match quite closely as to what QF achieve on the LHR-PER route as well as posts showing actual data from other airlines. The typical amount of fuel on board on landing for a 787 variant appears to be ~5t so there is no reason to assume that there would be anything special done for the sunrise routes and therefore no additional assumptions or reductions justified in the calculating of the capability.

Your "conservative" 184t OWE is in no way conservative and you'll see that the breguet derived equations shown further up in the thread have the same assumption. You still haven't included the relevant weight of the catering and other sundries being the difference between OWE and DOW.

You still need to explain the "performance factor" and where it was pulled from. I looked at the code as well and whilst I don't understand the specific language you appear to be doing the 8 cells and doing the calculation as shown up thread but seem to be scared of having the discussion about assumptions. Modifying the specific range part of the equations and assuming weights (and leaving others out).

I have posted the link so all can see and you don't have to worry about self promotion https://verovenia.wordpress.com/
I will allow others to pass their own judgement on weather there is technical merit to your posts.

One can only assume that if you cannot find the issues in the calculations and assumptions I posed that you agree with them...

Fred

At this rate, what they need to do is to land the aircraft in Changi and then taxi it to the remote stand for fueling and then take off again to london and or paris.
There, no need to get more headache about it.

flipdewaf wrote:

...

The Boeing ACAPS data and tables appear to match quite closely as to what QF achieve on the LHR-PER route as well as posts showing actual data from other airlines. The typical amount of fuel on board on landing for a 787 variant appears to be ~5t so there is no reason to assume that there would be anything special done for the sunrise routes and therefore no additional assumptions or reductions justified in the calculating of the capability.
...
I have posted the link so all can see and you don't have to worry about self promotion https://verovenia.wordpress.com/
I will allow others to pass their own judgement on weather there is technical merit to your posts.
...

The payload range validated the "rough calibration" of the model. Entering into the details at this stage is useless.

The chart given by Boeing below indicates that the 777-9 can carry 426 passengers at 225 lb per passengers over 7,285 nm.


Obviously the picture given by Boeing includes all the required stuff to fly with those passengers.


.
Below is payload chart with the point stated in the above. The estimated OEW, that is only the result of calibration relative to the information is stated in the payload range diagram. Obviously this payload range diagram is using the typical well known reserve fuel policy that is way too conservative for this kind of distances.
The estimated OEW (which is merely a result of matching 426 pax over 7,285 nm) happens to be around 407,300 lbs. It is the OEW (including catering waste water precharge, crew, unuseable fuel, documentation etc.) to carry 426 passengers.

The red point represents the number given by Boeing's picture, again I insist that the estimated OEW includes everything that is required to carry those passengers over 7,285 nm. And the estimated OEW is a result of the estimation, not a "bottom up" calculation. I also insist that the numbers given by Boeing certainly uses the usual industry standard contingency fuel with 5% of trip fuel and an alternate distance of 200 nm.

A more realistic fuel reserve of 7.4 tonnes or 16,353 lb, as indicated by the calculator picture below, allows to carry more than 200 passengers over 9,600 nm.

That's so simple to understand. You do not need more to evaluate its capability at this stage.

As for the 15% efficiency improvement, it is based on the fact GE initially announced that GE9X would be 12% better than GE90-115B from SFC perspective.

Later on they reduced the ambition to only 10% SFC improvement relative to the GE90-115B. From the wing geometry of the 777-9 we can deduce easily that the aspect ratio has increased by a significant amount. The estimated L/D (or aerodynamic finesse or Lift over Drag) improvement would be around 6 to 7%. However a credit for only 5% was used. So, using Breguet Leduc formula one can deduce the SAR (Specific Air Range) Improvement to be about 15%.

So yes, the 777-9 can carry more than 200 passengers over 9,600 nm equivalent still air distance.

The most agressive assumptions could give around 260 passengers over 9,600 nm, but it would include some weight optimization.

.
So you didn't notice the fuel reserve in the example was as little as 16,353 lb or only 7.4 tonnes ??????




.
All the above being said, there is absolutely no doubt Qantas will order some A330neo or A350 at one point as a kind of compensation for the cancellation of 8 A380. It would be consistent with the recent Emirates' A350 orders.

VV wrote:

All the above being said, there is absolutely no doubt Qantas will order some A330neo or A350 at one point as a kind of compensation for the cancellation of 8 A380. It would be consistent with the recent Emirates' A350 orders.

Off-topic but the outstanding A380s were converted into A321XLRs.

If Boeing wins the PS order then I doubt we will see another Airbus widebody enter QF’s fleet for a long time.

VV wrote:

The estimated OEW (which is merely a result of matching 426 pax over 7,285 nm) happens to be around 407,300 lbs. It is the OEW (including catering waste water precharge, crew, unuseable fuel, documentation etc.) to carry 426 passengers.

This is where I agree with flipdefwal. It is Operating EMPTY weight. So, an aircraft with all oils, unusable fuel, water, sure. But nothing for the passengers. No drinks, no food, no towels. No crew also (but I might be wrong here; the question anyways is are the numbers right?).

We're talking around 20hrs premium flight here. Plenty of crew, plenty of pantry. I'd say, that's around 7-8tons, maybe even 10t. I remember old flightplans for TATL, typical pantry was around 5 tons on 767-300ER and just over 200 seats.

Cheers,
Adam

gloom wrote:

VV wrote:

The estimated OEW (which is merely a result of matching 426 pax over 7,285 nm) happens to be around 407,300 lbs. It is the OEW (including catering waste water precharge, crew, unuseable fuel, documentation etc.) to carry 426 passengers.

This is where I agree with flipdefwal. It is Operating EMPTY weight. So, an aircraft with all oils, unusable fuel, water, sure. But nothing for the passengers. No drinks, no food, no towels. No crew also (but I might be wrong here; the question anyways is are the numbers right?).

We're talking around 20hrs premium flight here. Plenty of crew, plenty of pantry. I'd say, that's around 7-8tons, maybe even 10t. I remember old flightplans for TATL, typical pantry was around 5 tons on 767-300ER and just over 200 seats.

Cheers,
Adam

I am really sorry that people interpret OEW differently.

In my world, OEW is ZFW minus Payload.
For me any other interpretation is useless.

qf002 wrote:

VV wrote:

All the above being said, there is absolutely no doubt Qantas will order some A330neo or A350 at one point as a kind of compensation for the cancellation of 8 A380. It would be consistent with the recent Emirates' A350 orders.

Off-topic but the outstanding A380s were converted into A321XLRs.

If Boeing wins the PS order then I doubt we will see another Airbus widebody enter QF’s fleet for a long time.

Okay. So according to you Qantas ordered A321XLR as the compensation for the cancelled 8 A380.

From that information I have to deduce the following.

• Qantas is now free to order anything freely because they do not link the order to the A380 cancelled orders. I doesn't mean they cannot order Airbus widebody
• Airbus is more focused in undermining the NMA than to place A330neo or A350 at Qantas.

As a conclusion, I think your comment is very relevant.

VV wrote:

I am really sorry that people interpret OEW differently.

In my world, OEW is ZFW minus Payload.
For me any other interpretation is useless.

In the real world we use a dry operating weight, not operating weight. For example the number of crew and catering on 789 operating a short domestic like SYD-MEL is very different to PER-LHR.

zeke wrote:

VV wrote:

I am really sorry that people interpret OEW differently.

In my world, OEW is ZFW minus Payload.
For me any other interpretation is useless.

In the real world we use a dry operating weight, not operating weight. For example the number of crew and catering on 789 operating a short domestic like SYD-MEL is very different to PER-LHR.

It is just your way to express your weight.

Let's make clear that the OEW in the payload range and calculation above is ZFW minus payload.
Payload being defined as paying load, that is passenger weight and freight.

That's simple.

[quote="VV /quote]
So according to you, the 779 max payload begin to decrease even before 77W? The A35K is going to eat it alive ...

VV wrote:

zeke wrote:

VV wrote:

I am really sorry that people interpret OEW differently.

In my world, OEW is ZFW minus Payload.
For me any other interpretation is useless.

In the real world we use a dry operating weight, not operating weight. For example the number of crew and catering on 789 operating a short domestic like SYD-MEL is very different to PER-LHR.

It is just your way to express your weight.

And that's fine, How do you know 777-9X weights 184t when its got its catering on board?
Your OWE = Zeke's DOW (which is Zekes OWE + Crew + catering + water +Towels+My champagne) which would suggest that the Zeke OWE for the scenario where you could take the pax to the range you suggest would mean a OWE of well under 180t. Even without a new wing and higher operating weights the simple act of adding the fuselage would add nearly 7t to the 77W bringing it from an OWE of 167t to 174t and that doesnt account for a higher weight fuselage because of the sculpting to fit 10x in it.. The you need to add a wing that is 11% longer and no thicker and think you are going to get something well under 180t......

VV wrote:

Let's make clear that the OEW in the payload range and calculation above is ZFW minus payload.
Payload being defined as paying load, that is passenger weight and freight.

That's simple.

So you think its 184t when its got 5t of catering and water and towels and crew....

VV wrote:

A more realistic fuel reserve of 7.4 tonnes or 16,353 lb, as indicated by the calculator picture below, allows to carry more than 200 passengers over 9,600 nm.

Boeing's numbers for payload range figures fall in line almost exactly for the 787 as seen from the QF9/10 data publicly available as well as the united 787-10 data posted by jayunited on this site. The 787 in those instances lands with around 4.5-5t of fuel. This suggests that the Boeing payload range figures are pretty accurate and follow similar routing and contingency rules to those used in regular airline operations. Your assertion that the 777-9X would land with 7.5t in the case of QF would suggest a fuel burn in the order of 1.5X that of the 787. I'm afraid that your numbers are not passing the smell test no matter how world famous they are.

BTW I love your blog!

Fred

Edit: Added some highlighting.

flipdewaf wrote:

VV wrote:

zeke wrote:

In the real world we use a dry operating weight, not operating weight. For example the number of crew and catering on 789 operating a short domestic like SYD-MEL is very different to PER-LHR.

It is just your way to express your weight.

And that's fine, How do you know 777-9X weights 184t when its got its catering on board?
Your OWE = Zeke's DOW (which is Zekes OWE + Crew + catering + water +Towels+My champagne) which would suggest that the Zeke OWE for the scenario where you could take the pax to the range you suggest would mean a OWE of well under 180t. Even without a new wing and higher operating weights the simple act of adding the fuselage would add nearly 7t to the 77W bringing it from an OWE of 167t to 174t and that doesnt account for a higher weight fuselage because of the sculpting to fit 10x in it.. The you need to add a wing that is 11% longer and no thicker and think you are going to get something well under 180t......

VV wrote:

Let's make clear that the OEW in the payload range and calculation above is ZFW minus payload.
Payload being defined as paying load, that is passenger weight and freight.

That's simple.

So you think its 184t when its got 5t of catering and water and towels and crew....

Well, obviously yes. Where would you put the those items otherwise????

TOW = OEW + Payload + Fuel Reserves + planned fuel burn

In other words,
OEW + Payload = Zero Fuel Weight
Zero Fuel Weight + Fuel on board (at brake release) = TOW

mig17 wrote:

[quote="VV] /quote]
So according to you, the 779 max payload begin to decrease even before 77W? The A35K is going to eat it alive ...[/quote]

Well if you think A350-1000 can carry 155,000 lb of payload over 5,200 nm then you may be right. But no, A350-1000 will not eat 777-9 alive. LOL.

majano wrote:

VV wrote:

zeke wrote:

In the real world we use a dry operating weight, not operating weight. For example the number of crew and catering on 789 operating a short domestic like SYD-MEL is very different to PER-LHR.

It is just your way to express your weight.

Let's make clear that the OEW in the payload range and calculation above is ZFW minus payload.
Payload being defined as paying load, that is passenger weight and freight.

That's simple.

If that's the case then your 200 or 260 passengers means absolutely nothing.

Very seriously I do not know what you comment means. I just do not understand.

If you can explain to me the meaning of your comment then perhaps I will be able to help.

VV wrote:

flipdewaf wrote:

VV wrote:

It is just your way to express your weight.

And that's fine, How do you know 777-9X weights 184t when its got its catering on board?
Your OWE = Zeke's DOW (which is Zekes OWE + Crew + catering + water +Towels+My champagne) which would suggest that the Zeke OWE for the scenario where you could take the pax to the range you suggest would mean a OWE of well under 180t. Even without a new wing and higher operating weights the simple act of adding the fuselage would add nearly 7t to the 77W bringing it from an OWE of 167t to 174t and that doesnt account for a higher weight fuselage because of the sculpting to fit 10x in it.. The you need to add a wing that is 11% longer and no thicker and think you are going to get something well under 180t......

VV wrote:

Let's make clear that the OEW in the payload range and calculation above is ZFW minus payload.
Payload being defined as paying load, that is passenger weight and freight.

That's simple.

So you think its 184t when its got 5t of catering and water and towels and crew....

Well, obviously yes. Where would you put the those items otherwise????

TOW = OEW + Payload + Fuel Reserves + planned fuel burn

In other words,
OEW + Payload = Zero Fuel Weight
Zero Fuel Weight + Fuel on board (at brake release) = TOW

So on what basis do you think the OWE ( in the normal sense and not in your sense) will be this low? I.e. DOW at 184t and OWE well below 180t and far below any current estimates? I of course can give any aircraft any payload range performance if I make up OWE figures.

What basis do you have for thinking that Boeing are using a ‘very conservative’ reserves for the 777x when they appear to be using reserves that giver performance in line with real world operations for the 787?

Fred


Sent from my iPhone using Tapatalk

flipdewaf wrote:

...
What basis do you have for thinking that Boeing are using a ‘very conservative’ reserves for the 777x when they appear to be using reserves that giver performance in line with real world operations for the 787?
...

Okay. It seems we need to go deeper to explain it.

OEW= MEW + Customer Changes + Operator's items

Basically OEW is the operating empty weight without the payload. In the operator's items you have the crew, the flight attendants, the documentation, the waste water precharge, catering, and so on and so forth. MEW is the manufacturer's empty weight. The MEW + customer changes is often called the "customized MEW".

Now on top of the OEW you add the payload to obtain the Zero Fuel Weight. When you add the planned fuel for taxi-out, reserves and the expected fuel burn you have the ramp weight.

Once you have burnt the taxi fuel you are at TOW.

That's how it is defined in my world.

It is well known in the industry that the ZFW-range diagram published by the manufacturers used the EASA 5% contingency fuel although time to time Airbus seems to use the reduced contingency with only 3% contingency fuel. In addition, the alternate distance is usually is 200 nm. On top of those two items, you add 30 holding at 1,500 ft (above destination).

In cases airlines put a cap on the contingency fuel. Some other have different fuel reserve policy.
And obviously US domestic flight has the domestic fuel reserves (FAR §121.639) where the reserve fuel is the sum of the diversion plus the fuel for 45 minutes normal cruise. The FAA reserve fuel for flight outside the 48 contiguous United States and the District of Columbia should use the FAR §121.645. I let you find the text by yourself.

Now, it is more convenient for long-range widebody to use the EASA rule (CAT.OP.MPA.182). I leave you to find the relevant text by yourself, but basically it is as I described above (5% of trip fuel as contingency fuel + diversion + 30 min hold).

For generic presentation the diversion distance is 200 nm. That's what in Boeing's published ZFW-Range diagram in the Airplane Characteristics for Airport Planning document (ACAP). And yes, in cases 200 nm diversion is quite conservative and 5% of contingency fuel is very conservative for very long flight.

Now, in day-to-day operations you can adapt your fuel reserve while respecting the rules. In addition in cases you may have to add extra fuel to cover the most adverse of the three ETOPS failure scenarios. But we are not going into that detail.

Now, if you still do not understand, please ask.

flipdewaf wrote:

...
I of course can give any aircraft any payload range performance if I make up OWE figures.
...

Wrong.

The steps I did to estimate the 777-9 performance are very simple and any one can do it.

1. Try to estimate a known aircraft close enough to the 777-9. In this case it is the 777-300ER. There is fortunately a publicly available information that is the ZFW-Range diagram published by Boeing in the ACAP document. You need to know what exactly is in the diagram. One of the task is to understand the reserve used for the ZFW-Range diagram. It is explained in my previous comment.
2. Build a model that reproduces the ZFW-Range Diagram published by Boeing. That's what I did with the 777-300ER calculator
3. Estimate the efficiency improvement (at same gross weight) of the 777-9 relative to 777-300ER.
   We know that GE initially announced an SFC improvement target relative to GE90-115B. However, this target was then lowered to only 10%.
   From the airport compatibility published by Boeing, you measure the changes from geometry point of view. It appreas the aspect ratio is improved by about 7%. Considering the bigger nacelles and longer fuselage, we can take an overall lift-over-drag improvement of about 5%.
   The total improvement is about 15% in term of Specific Air Range at gross weight compared to the 777-300ER.
4. Find a reference point for calibration. This is given by Boeing in its 777-9 presentation in their website. The point of reference is 426 passengers at 225 lb per passenger over 7,285 nm.
5. Run you model iteratively until you find an OEW that matches the reference point of calibration. In the Sunrise case I found it to be around 407,300 lb.
6. From that point, you estimate other different missions. For example in this case the Project Sunrise.

It is really not so complicated.

And the result shows that the 777-9 can carry between 200-260 passengers over 9,600 nm depending how aggressive you are in term of assumptions for fuel reserve and also from possible weight saving effort between now and 2023.

Boeing defines OEW in their ACAPS as follows: "Weight of structure, powerplant, furnishing systems, unusable fuel and other unusable propulsion agents, and other items of equipment that are considered an integral part of a particular airplane configuration. Also included are certain standard items, personnel, equipment, and supplies necessary for full operations, excluding usable fuel and payload."

The devil is in the details, of course. Does Boeing consider catering/pantry as part of the "certain standard items" or "supplies necessary for full operations" or are they considered part of the "payload"?


Boeing lists the OEW for the 787-9 as just under 129,000kg at 290 seats in two classes (28J / 262Y) with 85" pitch suites at 2+2+2 in Business and 32" pitch in Economy at 3+3+3. This tracks with 128,000kg for Etihad's two-class 787-9, United's 787-9 and one other 787-9 that have been posted to this forum. However, I believe all three airline figures are Basic Empty Weight, which would not include the weight of catering/pantry.

I only have BEW and DOW figures for Emirates and Turkish Airlines. Their DOW figures do include catering/pantry, which is 3,000kg for Turkish and double that for Emirates (Emirates also adds another 2,000kg for other items to their DOW) - both for 777-300ERs.

Stitch wrote:

Boeing defines OEW in their ACAPS as follows: "Weight of structure, powerplant, furnishing systems, unusable fuel and other unusable propulsion agents, and other items of equipment that are considered an integral part of a particular airplane configuration. Also included are certain standard items, personnel, equipment, and supplies necessary for full operations, excluding usable fuel and payload."

The devil is in the details, of course. Does Boeing consider catering/pantry as part of the "certain standard items" or "supplies necessary for full operations" or are they considered part of the "payload"?

...

The most important phrase is underlined. Catering does NOT pay.

VV wrote:

flipdewaf wrote:

...
What basis do you have for thinking that Boeing are using a ‘very conservative’ reserves for the 777x when they appear to be using reserves that giver performance in line with real world operations for the 787?
...

Okay. It seems we need to go deeper to explain it.

It’s less about going deeper and more about answering the question posed.

VV wrote:

OEW= MEW + Customer Changes + Operator's items

Define it however you want, I don’t care, just answer the questions posed.

VV wrote:

Basically OEW is the operating empty weight without the payload. In the operator's items you have the crew, the flight attendants, the documentation, the waste water precharge, catering, and so on and so forth. MEW is the manufacturer's empty weight. The MEW + customer changes is often called the "customized MEW".

Again, no one really cares how you do it, it’s just a case of adding or subtracting those thing from the basic calculation.

VV wrote:

Now on top of the OEW you add the payload to obtain the Zero Fuel Weight. When you add the planned fuel for taxi-out, reserves and the expected fuel burn you have the ramp weight.

Once you have burnt the taxi fuel you are at TOW.

Oh jeez!

VV wrote:

That's how it is defined in my world.

Well if you are making assertions about it and have a source for your data you would think it would be good to define it how the source off your data also defines it.

The question is how you got to the figure you got to when it appears that you have a lower figure for what is normally defined as OWE (not your definition) than any source I have ever seen. Ranging from ~181t up to 188t

VV wrote:

It is well known in the industry that the ZFW-range diagram published by the manufacturers used the EASA 5%

Is it well known? Show that. Does it state it in the ACAPS?

VV wrote:

contingency fuel although time to time Airbus seems to use the reduced contingency with only 3% contingency fuel. In addition, the alternate distance is usually is 200 nm. On top of those two items, you add 30 holding at 1,500 ft (above destination).

In cases airlines put a cap on the contingency fuel. Some other have different fuel reserve policy.
And obviously US domestic flight has the domestic fuel reserves (FAR §121.639) where the reserve fuel is the sum of the diversion plus the fuel for 45 minutes normal cruise. The FAA reserve fuel for flight outside the 48 contiguous United States and the District of Columbia should use the FAR §121.645. I let you find the text by yourself.

Now, it is more convenient for long-range widebody to use the EASA rule (CAT.OP.MPA.182). I leave you to find the relevant text by yourself, but basically it is as I described above (5% of trip fuel as contingency fuel + diversion + 30 min hold).

For generic presentation the diversion distance is 200 nm. That's what in Boeing's published ZFW-Range diagram in the Airplane Characteristics for Airport Planning document (ACAP). And yes, in cases 200 nm diversion is quite conservative and 5% of contingency fuel is very conservative for very long flight.

Now, in day-to-day operations you can adapt your fuel reserve while respecting the rules. In addition in cases you may have to add extra fuel to cover the most adverse of the three ETOPS failure scenarios. But we are not going into that detail.

So the question I would like you to answer ( and I’ll define this completely) why do you believe that QF will be able to significantly beat the published payload range chart for the 779x when they match almost exactly the payload range capability of the Boeing published payload range charts for the 787? What reason do you have fob believing the 7779x range chart is or will be more conservative then the 787 one?

VV wrote:

Now, if you still do not understand, please ask.

I understand how some people wrote more and more like a nervous student in an exam putting everything they know on a piece of appear in the desperate hope to get marks. It’s better o just read the questions again and think.

Fred


Sent from my iPhone using Tapatalk

flipdewaf wrote:

...

I understand how some people wrote more and more like a nervous student in an exam putting everything they know on a piece of appear in the desperate hope to get marks. It’s better o just read the questions again and think.

Fred


Sent from my iPhone using Tapatalk

Seriously Fred???????

Please read Stitch comment.

VV wrote:

Seriously Fred???????

Please read Stitch comment.

I don't think Stitch proves your point though so not sure why you are saying to look at his post. He says Boeing isn't clear if catering is included in their OEW numbers and he uses examples of United and Etihad having a similar OEW to Boeing, before catering is added. So what I believe Fred is trying to point out, your OEW figure is wrong for the 779 as it needs to add weight for those items and Stitch has the 77W figures for TK and EK and they are 3000kg and 6000kg respectively. Add in extra crew for the PS flights and the extra catering they will need, and then see what the results are.

VV wrote:

In other words,
OEW + Payload = Zero Fuel Weight
Zero Fuel Weight + Fuel on board (at brake release) = TOW

Not in the real world. In the real world we would use a basic weight, the basic weight and basic index is derived from weighing the aircraft. It is the weight of the aircraft empty without crew and catering. This number is unique to the particular tail.

We then add the crew and catering for the specific route (can have for example 30 variations on the same type depending on the crew and catering carried for the sector) to come up with the dry operating weight, the weight of the crew and catering is the same for every aircraft. If you carry no passengers or cargo, the dry operating weight would be the zero fuel weight.

VV wrote:

It is well known in the industry that the ZFW-range diagram published by the manufacturers used the EASA 5% contingency fuel although time to time Airbus seems to use the reduced contingency with only 3% contingency fuel. In addition, the alternate distance is usually is 200 nm. On top of those two items, you add 30 holding at 1,500 ft (above destination).

This is not correct, the fuel policy used very much depends on the aircraft, Boeing uses FAA rules to develop their diagrams, and you need to have access to the actual data used to know what they have used. They do not use the same assumptions for each type. Airbus uses EU-OPS fuel policy, which is similar to what QF uses.

Neither Boeing or Airbus use a fixed contingency on their long haul products except from the destination to the alternate on their latest products. Final reserve is 30 minutes holding fuel over the alternate airport, not over the destination.