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ElroyJetson
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 2:56 pm

RJMAZ wrote:
MoKa777 wrote:
The A35K may use 2-3% less fuel than the 778 and may be 1-2% quicker as well. Add to this the fact that the A35K will be more versatile within the network than the 778, I see no operational (non-commercial) reason for QF to go for the 778.
You have completely misinterpreted the table. The 777-8 absolutely smashes the A350-1000 by a massive 10% in terms of fuel per kg of payload carried.

The 777-8 is listed in the table as performing the flight 10T below MTOW. The A350-1000 with a 150T DOW is taking off at the limit of the 316T MTOW.

So the 777-8 could essily add 5T of extra payload and 5T of fuel and take off at MTOW. This changes things completely.

The 777-8 would be lifting 35,000kg of payload burning 138,422kg of fuel. The A350-1000's would lift 30,000kg of payload burning 130,566kg of fuel.

4.3522 litres per kg versus 3.95 litres is more than a 10% advantage to the 777-8.

The 777-8 could then carry 5T of extra payload in the hold on your average flight. Or on a day when the weather is poor the 777-8 can can use that hesdroom to still carry a full passenger load the A350-1000 would require blocked rows of seats.

The A350-1000 needs a MTOW bump above 320T to come close to the 777-8.


Thanks. This is why I asked the payload question and the assumption of 30t for both aircraft. Payload is often additional revenue in terms of either pax or cargo.

So the question is which frame can carry the most payload the cheapest? Payload meaning revenue.

It sounds like you're saying the 778 is the best option. I have seen payload range charts for both aircraft and their is no question the 778 can carry more payload farther. But as always there are many variables in play.
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jupiter2
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 3:06 pm

zeke wrote:
jupiter2 wrote:
I'm surprised at how efficient the 778 looks to be compared to the 35K considering the weight differences. However, I don't agree with you that this points to the 35K being more versatile for QF.


Where we have run the 779 with plans over our network the fuel burn delta and flight time delta is greater, but what Fred has done is still a lot better than guessing.

jupiter2 wrote:
Whichever aircraft is chosen is going to be in a unique, premium heavy configuration and when placed on shorter routes will equally be more fuel efficient than when doing the Sunrise flights, so while the 35K may burn less fuel, the percentage difference implied by the excellent table provided by


Fuel is only part of the consideration, other direct costs like landing and navigation fees are based upon weight. The QF crew wages are also linked to weight of the aircraft, an A380 captain earns more than an A330 one.

Maintenance costs will be higher for the 778, and the purchase price is likely to be around 25 million more per frame.

Realistically I think it’s too close to call, I see advantages and disadvantages either way.


I realise you have access to more complete data and I have no reason to doubt what you say, but as you say, what Fred has done as a pretty guide for those of us without that access.

Why would maintenance costs be higher for the 778 ? Purchase price, well that's part of the reason why I think that a bigger deal than just Sunrise aircraft will be negotiated. QF has both manufacturers keen to get this business and is in a strong negotiating position, whichever way they go, I'm sure QF will get a really good deal out of this.

I do agree wholeheartedly, that this is a very close call and could go either way. Personally I would prefer the 777, but that's a purely selfish reason that I've always wanted to see a QF 777, but ultimately I don't care, as long as what they get does what QF wants to try and that it turns out to be a success.
 
flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 3:53 pm

ElroyJetson wrote:
flipdewaf wrote:
I guess this is the best way to post this. There i to variants of the A35K for comparison. One with DOW at 147000kg and one with DOW at 150000kg. The TSFC is listed in the data.
Image

Fred



It is amazing how close fuel burn is for both frames. My question is in regards to the assumed 30t payload.

Where is this assumption coming from? Second, is it certain both frames have the legs to fly the mission at 30t?

And btw....thanks for the information. It is very interesting.

30t payload as that was the original goal from QFif I remember rightly. Yes it appears they both do.
RJMAZ wrote:
MoKa777 wrote:
The A35K may use 2-3% less fuel than the 778 and may be 1-2% quicker as well. Add to this the fact that the A35K will be more versatile within the network than the 778, I see no operational (non-commercial) reason for QF to go for the 778.
You have completely misinterpreted the table. The 777-8 absolutely smashes the A350-1000 by a massive 10% in terms of fuel per kg of payload carried.
It carried 30t of payload and burned more fuel in the model therefore it burned more fuel per kg carried. You want to compare like for like then put an extra 5t in each.

RJMAZ wrote:
The 777-8 is listed in the table as performing the flight 10T below MTOW. The A350-1000 with a 150T DOW is taking off at the limit of the 316T MTOW.
It is has been reported by not unreliable sources that a weight varient with 320tMTOW will be available.

RJMAZ wrote:
So the 777-8 could essily add 5T of extra payload and 5T of fuel and take off at MTOW. This changes things completely.
Of course it does.

RJMAZ wrote:
The 777-8 would be lifting 35,000kg of payload burning 138,422kg of fuel. The A350-1000's would lift 30,000kg of payload burning 130,566kg of fuel.
Really? if we put 7kg things would change as well.

RJMAZ wrote:
4.3522 litres per kg versus 3.95 litres is more than a 10% advantage to the 777-8.

The 777-8 could then carry 5T of extra payload in the hold on your average flight. Or on a day when the weather is poor the 777-8 can can use that hesdroom to still carry a full passenger load the A350-1000 would require blocked rows of seats.
The thing is on days where the weather gets much worse than it is depicted in these models you'll likely just go the (an) other way, the great thing about (almost (antipodean) flights is that everywhere is en-route.

The A350-1000 needs a MTOW bump above 320T to come close to the 777-8.[/quote] Or if the numbers presented about the actual weights of the A351 are correct then they seem on a par with 10t spare in each case...Except that its more efficient when you are able to cruise faster into those headwinds...

Fred
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zeke
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 4:54 pm

RJMAZ wrote:
You have completely misinterpreted the table. The 777-8 absolutely smashes the A350-1000 by a massive 10% in terms of fuel per kg of payload carried.


I like the way you think, be a good fit for Jet Airways.

jupiter2 wrote:
I realise you have access to more complete data and I have no reason to doubt what you say, but as you say, what Fred has done as a pretty guide for those of us without that access.


The exact methods and assumptions used by airlines to select aircraft are highly proprietary. The business decisions resulting from the analysis has long term ramifications. I have gone about as far as I can on here. Computers are only as good as the information that is used as input and the people operating them.

We have the luxury of a team of performance engineers and actual performance databases, actual historical loads etc. To get to where this is now is fantastic.

jupiter2 wrote:
Why would maintenance costs be higher for the 778 ?


Larger aircraft just cost more to maintain. For example a 737 tyre brakes oil and paint requirements would be less than a 777. Maintenance is also time based, so a slower aircraft will cost more per sector.

jupiter2 wrote:
Purchase price, well that's part of the reason why I think that a bigger deal than just Sunrise aircraft will be negotiated. QF has both manufacturers keen to get this business and is in a strong negotiating position, whichever way they go, I'm sure QF will get a really good deal out of this.


Both OEMs have good backlogs I don’t think they will be that keen.
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Eyad89
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 5:18 pm

RJMAZ wrote:

Wingspan 13% higher.


No, it is not! 778 has an effective wingspan that is longer by around 5.7%.

When calculating drag, we should consider the effective wingspan, not the physical wing span. Effective wingspan would be the wingspan without the wingtip device + the equivalent span of the wingtip device. The air flow behind and around the wing (and hence induced drag) cares only about the effective span, it does not care about the physical span that is mainly important for airport clearances.

Since 778 has a raked wingtip, its effective span would be 64.75 + (0.8*7) = 70.35m
Since A35k has a blended wingtip, its effective span would be 64.75 + (0.45*4) = 66.55m

In that case, 778 has an effective span that is longer by 5.7%. Since 778 is heavier by 11% at MTOW, then A35K clearly has less induced drag at MTOW even though it has a shorter effective span.

Only if A35K had a TOW of 333t would it have more induced drag than 778 at 351t at TOW.

As for parasitic drag, 778 has a slightly bigger fuselage, and it also has bigger wings and engines that are more draggy as well.

778 has more lift, but A35k has less drag (both induced and parasitic). Overall, their L/D ratios will be extremely close to each other, they might end up being as close as 1% of each other.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 5:33 pm

zeke wrote:
RJMAZ wrote:
You have completely misinterpreted the table. The 777-8 absolutely smashes the A350-1000 by a massive 10% in terms of fuel per kg of payload carried.


I like the way you think, be a good fit for Jet Airways.

jupiter2 wrote:
I realise you have access to more complete data and I have no reason to doubt what you say, but as you say, what Fred has done as a pretty guide for those of us without that access.


The exact methods and assumptions used by airlines to select aircraft are highly proprietary. The business decisions resulting from the analysis has long term ramifications. I have gone about as far as I can on here. Computers are only as good as the information that is used as input and the people operating them.

We have the luxury of a team of performance engineers and actual performance databases, actual historical loads etc. To get to where this is now is fantastic.

jupiter2 wrote:
Why would maintenance costs be higher for the 778 ?


Larger aircraft just cost more to maintain. For example a 737 tyre brakes oil and paint requirements would be less than a 777. Maintenance is also time based, so a slower aircraft will cost more per sector.

jupiter2 wrote:
Purchase price, well that's part of the reason why I think that a bigger deal than just Sunrise aircraft will be negotiated. QF has both manufacturers keen to get this business and is in a strong negotiating position, whichever way they go, I'm sure QF will get a really good deal out of this.


Both OEMs have good backlogs I don’t think they will be that keen.


- Indeed, as I said before, I appreciate the input yourself and Fred in particular have put into this thread, it's given the lay person such as myself a pretty good insight and I think most people would understand that there is a lot more than just fuel burn and acquisition cost involved.

- Fair enough, if it's just on the basis of the 778 being a larger aircraft that's easily understood.

- I just think there's a bit of extra spice and prestige involved in this RFP. Obviously the winner will gloat short term (and their respective fan boys) but the loser will hardly be under the microscope for not getting the order either.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 5:49 pm

jupiter2 wrote:
- Fair enough, if it's just on the basis of the 778 being a larger aircraft that's easily understood.


Larger and slower, over a year probably looking at an extra 300+ hrs of flying.
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StTim
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:08 pm

zeke wrote:
jupiter2 wrote:
- Fair enough, if it's just on the basis of the 778 being a larger aircraft that's easily understood.


Larger and slower, over a year probably looking at an extra 300+ hrs of flying.
Or 20 long haul revenue flights.

I asked earlier how sensitive the model is to changes in the TSFC of the engines. Do we have an answer as I thhink you believe they will be closer than currently in the model.

Also we have some pretty reliable figures for the Bus but obviously no actual figures for the 777X

The timing looks to be in favour of Airbus as the basic frame is in production with the weight reductions etc coming through. The early 777X frames are likely to be sub optimal for such an edge of the envelope role as historically early frames carry a bit of puppy fat.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:15 pm

zeke wrote:
jupiter2 wrote:
- Fair enough, if it's just on the basis of the 778 being a larger aircraft that's easily understood.


Larger and slower, over a year probably looking at an extra 300+ hrs of flying.


That much ? I mean they will probably only average one sector a day if most of the flights are getting up to 20 hours. Do most airlines use the same cruise speed, or do they vary from carrier to carrier ? I can remember years ago on a QF 744 passing a UA 744 doing the same SYD/LAX sector, we were slightly higher, so I wouldn't think the winds would've been that different, but we passed it quite quickly which was surprising.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:20 pm

zeke wrote:
jupiter2 wrote:
- Fair enough, if it's just on the basis of the 778 being a larger aircraft that's easily understood.

Larger and slower, over a year probably looking at an extra 300+ hrs of flying.


There are 8760 hours available in a year. 300 hours is 3.4% of that figure. So both planes would need to fly an entire year, 24hrs a day non-stop...and the A351 would need to fly it faster by 3.4% (not the 1-2% cited in the charts) to necessitate 300 extra flight hours for the 778.

Realistically, the planes will fly 20 hours a day (then wait to fly back the next day). 20 hrs * 364 (lets say they spend at least 1 day a year out of service. ;) ) = 7300 hours... but at a 2% performance delta, the 778 would need 146 extra hours to fly the same distance as it's the slower plane.

I took worst case scenario (max availability / greater flight time delta) and came up with half of 300 hours. Are my assumptions wrong?
Last edited by ODwyerPW on Fri May 10, 2019 6:21 pm, edited 1 time in total.
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flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:20 pm

StTim wrote:

I asked earlier how sensitive the model is to changes in the TSFC of the engines. Do we have an answer as I thhink you believe they will be closer than currently in the model.
sorry, probably not till late Monday. It takes about 25-30 minutes to run through a flight of this length and it ties up excel completely so even if I do break out my laptop during the weekend it’ll be to do my paid job.

Fred



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StTim
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:22 pm

flipdewaf wrote:
StTim wrote:

I asked earlier how sensitive the model is to changes in the TSFC of the engines. Do we have an answer as I thhink you believe they will be closer than currently in the model.
sorry, probably not till late Monday. It takes about 25-30 minutes to run through a flight of this length and it ties up excel completely so even if I do break out my laptop during the weekend it’ll be to do my paid job.

Fred



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Thanks Fred - I really appreciate your input to this discussion.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:34 pm

ODwyerPW wrote:
zeke wrote:
jupiter2 wrote:
- Fair enough, if it's just on the basis of the 778 being a larger aircraft that's easily understood.

Larger and slower, over a year probably looking at an extra 300+ hrs of flying.


There are 8760 hours available in a year. 300 hours is 3.4% of that figure. So both planes would need to fly an entire year, 24hrs a day non-stop...and the A351 would need to fly it faster by 3.4% (not the 1-2% cited in the charts) to necessitate 300 extra flight hours for the 778.

Realistically, the planes will fly 20 hours a day (then wait to fly back the next day). 20 hrs * 364 (lets say they spend at least 1 day a year out of service. ;) ) = 7300 hours... but at a 2% performance delta, the 778 would need 146 extra hours to fly the same distance as it's the slower plane.

I took worst case scenario (max availability / greater flight time delta) and came up with half of 300 hours. Are my assumptions wrong?


That's what I was thinking too, about half of what Zeke said, I just thought I must've been missing something somewhere.
 
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zeke
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:46 pm

Probably need at least 4 aircraft for the single frequency, depending on how they want to time it.
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morrisond
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 6:48 pm

jupiter2 wrote:
ODwyerPW wrote:
zeke wrote:
Larger and slower, over a year probably looking at an extra 300+ hrs of flying.


There are 8760 hours available in a year. 300 hours is 3.4% of that figure. So both planes would need to fly an entire year, 24hrs a day non-stop...and the A351 would need to fly it faster by 3.4% (not the 1-2% cited in the charts) to necessitate 300 extra flight hours for the 778.

Realistically, the planes will fly 20 hours a day (then wait to fly back the next day). 20 hrs * 364 (lets say they spend at least 1 day a year out of service. ;) ) = 7300 hours... but at a 2% performance delta, the 778 would need 146 extra hours to fly the same distance as it's the slower plane.

I took worst case scenario (max availability / greater flight time delta) and came up with half of 300 hours. Are my assumptions wrong?


That's what I was thinking too, about half of what Zeke said, I just thought I must've been missing something somewhere.


On the other hand could GE9x's be better on Maintenance as XWB-97 Engines are run at higher speeds to get the required thrust? Are the overhaul/inspection intervals the same?
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 7:40 pm

ElroyJetson wrote:
flipdewaf wrote:
I guess this is the best way to post this. There i to variants of the A35K for comparison. One with DOW at 147000kg and one with DOW at 150000kg. The TSFC is listed in the data.
Image

Fred



It is amazing how close fuel burn is for both frames. My question is in regards to the assumed 30t payload.

Where is this assumption coming from? Second, is it certain both frames have the legs to fly the mission at 30t?

And btw....thanks for the information. It is very interesting.

I fully expect the GE engine to have even lower TSFC. It has variable turbine cooling, more precise turbine clearance control, and a rediculous number of cooling looks on the engine. All of that stuff adds weight and cost to the engine, all benefits long haul fuel burn.

The competition is still too close to call. Just a data point.

Lightsaber
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zeke
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 7:48 pm

Some of that is on the XWB-97 as well, the core is different to the way RR traditionally had done things.

GE said the GE9X is to be 10% better than the GE90 (which most people would assume to be TSFC). I know the A35K beats the 77W by about 20% now on block fuel.

Just another data point ;)
Last edited by zeke on Fri May 10, 2019 7:53 pm, edited 1 time in total.
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 7:50 pm

One more data point, using the before quoted numbers
Max payload
A351 33,259 kg
778. 36,287

Again, as I posted above, I expect the GE engine to have an even lower TSFC. I forgot to mention CMCs. That is a further advantage to GE.

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usax777
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 8:09 pm

RJMAZ wrote:
MoKa777 wrote:
The A35K may use 2-3% less fuel than the 778 and may be 1-2% quicker as well. Add to this the fact that the A35K will be more versatile within the network than the 778, I see no operational (non-commercial) reason for QF to go for the 778.
You have completely misinterpreted the table. The 777-8 absolutely smashes the A350-1000 by a massive 10% in terms of fuel per kg of payload carried.

The 777-8 is listed in the table as performing the flight 10T below MTOW. The A350-1000 with a 150T DOW is taking off at the limit of the 316T MTOW.

So the 777-8 could essily add 5T of extra payload and 5T of fuel and take off at MTOW. This changes things completely.

The 777-8 would be lifting 35,000kg of payload burning 138,422kg of fuel. The A350-1000's would lift 30,000kg of payload burning 130,566kg of fuel.

4.3522 litres per kg versus 3.95 litres is more than a 10% advantage to the 777-8.

The 777-8 could then carry 5T of extra payload in the hold on your average flight. Or on a day when the weather is poor the 777-8 can can use that hesdroom to still carry a full passenger load the A350-1000 would require blocked rows of seats.

The A350-1000 needs a MTOW bump above 320T to come close to the 777-8.


I completely agree with you. A350 doesn't have a slightest chance wining this project against 777-8. It's amazing to see 777-8 carries much more payload at this extremely long distance and yet burns less fuel per kg payload than A350, even the A350-1000 is given the most optimistic DOW.

The whole idea of involving A350-1000 into the discussion in Project Sunrise is nothing more than a negotiation tactic with Boeing. There is no way A350-1000 can make it.
 
moyangmm
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 8:17 pm

I wonder if a MTOW-increased 787-10 can be considered for Project Sunrise. I think if Boeing managed to bump 787-10 to around 280t it could be able to do it much more efficiently than A350-1000.
 
flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 8:18 pm

lightsaber wrote:
ElroyJetson wrote:
flipdewaf wrote:
I guess this is the best way to post this. There i to variants of the A35K for comparison. One with DOW at 147000kg and one with DOW at 150000kg. The TSFC is listed in the data.
Image

Fred



It is amazing how close fuel burn is for both frames. My question is in regards to the assumed 30t payload.

Where is this assumption coming from? Second, is it certain both frames have the legs to fly the mission at 30t?

And btw....thanks for the information. It is very interesting.

I fully expect the GE engine to have even lower TSFC. It has variable turbine cooling, more precise turbine clearance control, and a rediculous number of cooling looks on the engine. All of that stuff adds weight and cost to the engine, all benefits long haul fuel burn.

The competition is still too close to call. Just a data point.

Lightsaber

Yes, we have a few data points based on models that have some error with assumptions on starting figures that have some flex based on engines that change over time whilst flying through windy conditions during different periods of the year with differing loads. That doesn’t even factor in the cost of the plane the navigation fees, the maintenance, the crew, the ground support systems and training and even then it’s for just one route and realistically QF have to make this work on a network level and even integrate with other carriers. An aircraft could easily burn more fuel to carry lower payload and be a mor expensive aircraft to buy but still be a better option to select for QF.

Still, Top trumps is fun!

Fred


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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 8:20 pm

usax777 wrote:

I completely agree with you. A350 doesn't have a slightest chance wining this project against 777-8. It's amazing to see 777-8 carries much more payload at this extremely long distance and yet burns less fuel per kg payload than A350, even the A350-1000 is given the most optimistic DOW.

The whole idea of involving A350-1000 into the discussion in Project Sunrise is nothing more than a negotiation tactic with Boeing. There is no way A350-1000 can make it.


Shock horror, the resident cynic doesn't think the A350 can fly a route, even in the face of all evidence.

If the A35K couldn't make it, it wouldn't be in the running, QF is run by fairly smart people, and they have access to the information, unlike you. Unless you, a person on the internet who can't even get their arguments right despite having had multiple pieces of evidence presented to you know better than QF's management (and DL's for that matter). Your talents are wasted here, you should be running an airline (and telling them never to buy A350s, ever).
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 8:23 pm

moyangmm wrote:
I wonder if a MTOW-increased 787-10 can be considered for Project Sunrise. I think if Boeing managed to bump 787-10 to around 280t it could be able to do it much more efficiently than A350-1000.


It would be delivered a lot later than an A35K or 778, and there's been next to zero indication that any MTOW increase is forthcoming for the 787. If I have it correct, it would also require some big changes as the landing gear is nearly maxed out. To get the range increase you would need to sacrifice efficiency, and the cost of developing this plane would weigh against it.

I think this one will have to be put down to fantasy, the same fantasy world where an A350 can't fly LAX-SYD.
 
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zeke
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 8:37 pm

MrHMSH wrote:
I think this one will have to be put down to fantasy, the same fantasy world where an A350 can't fly LAX-SYD.


I think it has been shown the A350 could not do LAX-SYD, it could only do LAX-MEL, LAX-BNE, LAX-CBR. Likewise it was shown it cannot do JFK-CAN, but it can do JFK-MNL or EWR-HKG.

Apparently the A350 cannot do SYD-LHR, only SYD-LGW, SYD-STN, and SYD-MAN.
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redroo
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 9:09 pm

Some fascinating technical discussion. Thank you!

Changing topic slightly. What do we think the flight time will be north and south bound? I’m not fussed about the differences between the 778 and A350, just what we think the overall time would be and the savings it would represent. I’m guess more around 21 hours and 24 hours. There is a fair bit of variation in the QF9/10 flight times.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 9:20 pm

redroo wrote:
Some fascinating technical discussion. Thank you!

Changing topic slightly. What do we think the flight time will be north and south bound? I’m not fussed about the differences between the 778 and A350, just what we think the overall time would be and the savings it would represent. I’m guess more around 21 hours and 24 hours. There is a fair bit of variation in the QF9/10 flight times.

This is just my speculation but with it being so close to being half way around it will have a huge amount of available variation in a available and reasonable paths to take and take advantage of the best winds. You will regularly see SQ21 going easy and over the uk back to sin and these flights will likely be the same going effectively the ‘wrong way’. Flight times will certainly vary but in percentage terms not nearly as much as you’d see on the North Atlantic.

Fred


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JerseyFlyer
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 9:37 pm

A few random thoughts about the Airbus solutions to what looks an evenly balanced selection between A and B on sunrise.

I think the sunrise fleet may end up being for more frames than generally expected in this thread. The focus is mostly on SYD, but MEL is surely equally valid given the finance houses based there. Also PER if the sucess of the 789 requires upguaging the current nonstop LHR route to a larger frame.

The Airbus option gets complicated looking at opportunities further ahead. In 10 years or so I expect an ultrafan stretched A3510 to be available in time for QF's A380 replacement cycle. An ultrafan 320t A3510 is probably the ideal sunrise solution, but not available in time.

Airbus would I am sure like to place A330neos with QF to replace their domestic A330ceos. I know 787s seem to be the domestic solution at the moment, and QF have good pricing on options, but QF may draw from DL's example of needing a perceived "premium" economy cabin at 8 abreast for their loyal domestic customer base. There has been a lot of frame-swapping between QF and Jetstar in the past and may be more in the future.

There are certainly options for an Airbus package to comprise more than the sunrise frames.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 10:43 pm

MrHMSH wrote:
If the A35K couldn't make it, it wouldn't be in the running, QF is run by fairly smart people, and they have access to the information, unlike you.


Well they can't be that smart, otherwise they would have already ordered the 778! :wink2:

Judging by some of the comments in this thread, one would be tempted to wonder why any sane airline would ever consider the A350. :sarcastic:
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musman9853
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 11:01 pm

on a somewhat different note, do we know when they might announce the order? Paris maybe?
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RJMAZ
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 11:20 pm

ElroyJetson wrote:
Thanks. This is why I asked the payload question and the assumption of 30t for both aircraft. Payload is often additional revenue in terms of either pax or cargo.

So the question is which frame can carry the most payload the cheapest? Payload meaning revenue.

It sounds like you're saying the 778 is the best option. I have seen payload range charts for both aircraft and their is no question the 778 can carry more payload farther. But as always there are many variables in play.

Yes the 777-8 is by far the cheapest per kg of payload.

I guess this is similar to the A350-900 versus the 787-9. If you put 30,000kg into both aircraft on a long route the 787-9 will always burn less fuel per kg. But on any flight the A350-900 will be further away from its MTOW as it is more capable. On SFO-SIN and LAX-SIN the A350-900 could carry more payload percentage wise than the extra fuel burnt. The A350-900 then has lower fuel burn per kg.

On most payload range charts at the extreme range end it becomes a very sharp decline. Significant payload must be removed from the plane to get a small increase in range. The A350-1000 will enter this territory more often as it has less headroom for bad weather. This is why United cancelled LAX-SIN as the 787-9 entered that part of the payload range chart quite often.

flipdewaf wrote:
It carried 30t of payload and burned more fuel in the model therefore it burned more fuel per kg carried. You want to compare like for like then put an extra 5t in each.

Take both aircraft up to their MTOW using your data and the 777-8 still burns much less fuel per kg of payload. Despite the slightly higher trip burn for the 777-8 the extra payload available is higher percentage wise.

The simple reason for this is when you take payload from say 30T to 40T on a very long flight that is a 33% increase. The total flying weight of the aircraft does not increase by 33% it would increase by less than 10%.

Eyad89 wrote:
RJMAZ wrote:

Wingspan 13% higher.


No, it is not! 778 has an effective wingspan that is longer by around 5.7%.

You have to remove the fuselage width from the wingspan. That then gives you the size of the actual wings. So you just wasted time doing those calcuations.
 
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cpd
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 11:30 pm

flipdewaf wrote:
redroo wrote:
Some fascinating technical discussion. Thank you!

Changing topic slightly. What do we think the flight time will be north and south bound? I’m not fussed about the differences between the 778 and A350, just what we think the overall time would be and the savings it would represent. I’m guess more around 21 hours and 24 hours. There is a fair bit of variation in the QF9/10 flight times.

This is just my speculation but with it being so close to being half way around it will have a huge amount of available variation in a available and reasonable paths to take and take advantage of the best winds. You will regularly see SQ21 going easy and over the uk back to sin and these flights will likely be the same going effectively the ‘wrong way’. Flight times will certainly vary but in percentage terms not nearly as much as you’d see on the North Atlantic.

Fred


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Qantas has a pretty interesting flight planning software/platform that does look at all the possibilities for routes. It was shown in an RAeS lecture a while back. So I wouldn’t be surprised if we end up seeing some of these flights taking unusual routes.

Must say, this is by far the best off topic discussion I’ve seen in a while.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Fri May 10, 2019 11:53 pm

The 777-8 would be a fascinating aircraft to fly SYD-LHR. It's empty weight is 25 t more than a A350-1000 though. That's a lot of dead metal to fly around for 20 hours at 500 kts.

Maybe there will be an A359 XLR, a simple 320t A350-1000 shrink, for Virgin, to do the prestigious LHR-AKL, which can be flown in any direction, as long as you fly in straight line. :wink2:

Honestly, I doubt either Airbus or Boeing wants to invest too much, for maybe 10 or 20 aircraft. There has to be some ROI.. Whatever QF says
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Eyad89
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 2:55 am

RJMAZ wrote:

You have to remove the fuselage width from the wingspan. That then gives you the size of the actual wings.


No, it doesn't work that way! The wingspan is only the horizontal distance between the two wingtips. The air doesn't care how much of that distance is fuselage.

We are not talking about the lift force here, the area or dimensions of the wing do not matter here.

We are talking about induced drag, and this type of drag is simply the energy wasted by the air circular movement around the wingtips as a result of lift. This air movement is along the entire span of the wing, not just its tip. In order to reduce this drag, this circular air movement should be made slower. Two things can do that, either reduce the lift force (weight) or make the spanload distribution wider (wingspan). It doesn't matter if the fuselage is 1 meter or 20 meters as long as the circulating air is distributed over a longer distance (which is the distance between the two wingtips).

RJMAZ wrote:
So you just wasted time doing those calculations.

Unlike the misleading figure of physical wingspan that you referred to, the effective wingspan dictates how wide the air is circulating around the wingtip, and that makes your calculation of induced drag more accurate.
 
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 3:01 am

scbriml wrote:
Judging by some of the comments in this thread, one would be tempted to wonder why any sane airline would ever consider the A350. :sarcastic:


In the interests of saving weight Airbus didn’t install thorniresistors into the wings of the A350, this makes it impossible to fly some routes due to the qubit drag rise. I understand the 777-X has 4 thorniresistors installed (2 in each wing) which allows it to have laminar qubit plasma flow around the aircraft.

RJMAZ wrote:
Take both aircraft up to their MTOW using your data and the 777-8 still burns much less fuel per kg of payload. Despite the slightly higher trip burn for the 777-8 the extra payload available is higher percentage wise.


Qantas is one of these dreams unique airlines that does not need to pay for its aircraft, maintenance, navigation charges, landing charges, crew etc. They just pay for fuel, and always have 100% load factors.


RJMAZ wrote:
The simple reason for this is when you take payload from say 30T to 40T on a very long flight that is a 33% increase. The total flying weight of the aircraft does not increase by 33% it would increase by less than 10%.


Interesting I thought range was proportional to the natural log of the final weight minus the initial weight.
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 3:27 am

musman9853 wrote:
on a somewhat different note, do we know when they might announce the order? Paris maybe?


Two schools of thought

1) never, they are setting AIPA up with the contract negotiations for the blame

2) end of year
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
Waterbomber2
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 4:28 am

StTim wrote:
If the TSFC was the same for the Bus what sort of difference would it make?


Irrelevant because these are purely ballpark theoretical numbers.
On the same test bench, the TSFC would be different between morning and evening.
When yoh run 20 hour flights, reliability and durability becomes more important.

I also doubt that the GE9X would beat the A350XWB on TSFC.

zeke wrote:
scbriml wrote:
Judging by some of the comments in this thread, one would be tempted to wonder why any sane airline would ever consider the A350. :sarcastic:


In the interests of saving weight Airbus didn’t install thorniresistors into the wings of the A350, this makes it impossible to fly some routes due to the qubit drag rise. I understand the 777-X has 4 thorniresistors installed (2 in each wing) which allows it to have laminar qubit plasma flow around the aircraft.

RJMAZ wrote:
Take both aircraft up to their MTOW using your data and the 777-8 still burns much less fuel per kg of payload. Despite the slightly higher trip burn for the 777-8 the extra payload available is higher percentage wise.


Qantas is one of these dreams unique airlines that does not need to pay for its aircraft, maintenance, navigation charges, landing charges, crew etc. They just pay for fuel, and always have 100% load factors.


RJMAZ wrote:
The simple reason for this is when you take payload from say 30T to 40T on a very long flight that is a 33% increase. The total flying weight of the aircraft does not increase by 33% it would increase by less than 10%.


Interesting I thought range was proportional to the natural log of the final weight minus the initial weight.


What are thorniresistors? What is qubit plasma flow?
I don't know how those relate to aerodynamics, would like to learn.
 
musman9853
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 4:35 am

zeke wrote:
musman9853 wrote:
on a somewhat different note, do we know when they might announce the order? Paris maybe?


Two schools of thought

1) never, they are setting AIPA up with the contract negotiations for the blame

2) end of year



Interesting, so I'm assuming Qantas can't have it's pilots fly the route under the current contract then?
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aryonoco
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 4:45 am

Just wanted to thank zeke and Fred for their amazing input to this thread.

It has been one of the most useful threads I've seen here in a long time.

Just a note to Fred, from a computer scientist, if your Excel model is taking that long to run, you might want to look into translating it into something more suitable such as R in future.
 
flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 5:29 am

Waterbomber2 wrote:
StTim wrote:
If the TSFC was the same for the Bus what sort of difference would it make?


Irrelevant because these are purely ballpark theoretical numbers.
On the same test bench, the TSFC would be different between morning and evening.
When yoh run 20 hour flights, reliability and durability becomes more important.

I also doubt that the GE9X would beat the A350XWB on TSFC.

zeke wrote:
scbriml wrote:
Judging by some of the comments in this thread, one would be tempted to wonder why any sane airline would ever consider the A350. :sarcastic:


In the interests of saving weight Airbus didn’t install thorniresistors into the wings of the A350, this makes it impossible to fly some routes due to the qubit drag rise. I understand the 777-X has 4 thorniresistors installed (2 in each wing) which allows it to have laminar qubit plasma flow around the aircraft.

RJMAZ wrote:
Take both aircraft up to their MTOW using your data and the 777-8 still burns much less fuel per kg of payload. Despite the slightly higher trip burn for the 777-8 the extra payload available is higher percentage wise.


Qantas is one of these dreams unique airlines that does not need to pay for its aircraft, maintenance, navigation charges, landing charges, crew etc. They just pay for fuel, and always have 100% load factors.


RJMAZ wrote:
The simple reason for this is when you take payload from say 30T to 40T on a very long flight that is a 33% increase. The total flying weight of the aircraft does not increase by 33% it would increase by less than 10%.


Interesting I thought range was proportional to the natural log of the final weight minus the initial weight.


What are thorniresistors? What is qubit plasma flow?
I don't know how those relate to aerodynamics, would like to learn.

I think they are a bit like turbo encabulators.

Fred


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zeke
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 5:44 am

Waterbomber2 wrote:
What are thorniresistors? What is qubit plasma flow?
I don't know how those relate to aerodynamics, would like to learn.


I am still learning myself, only just learned that the A350 could not fly LAX-SYD or SYD-LHR. Only thing I could put it down to is qubit plasma flow and no thorniresistors.


musman9853 wrote:
Interesting, so I'm assuming Qantas can't have it's pilots fly the route under the current contract then?


The 777/A350 are not in the contract, nor are such long sectors.
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flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 5:46 am

RJMAZ wrote:

flipdewaf wrote:
It carried 30t of payload and burned more fuel in the model therefore it burned more fuel per kg carried. You want to compare like for like then put an extra 5t in each.

Take both aircraft up to their MTOW using your data and the 777-8 still burns much less fuel per kg of payload. Despite the slightly higher trip burn for the 777-8 the extra payload available is higher percentage wise.


Using my data? We’re you in my house last night?

My model doesn’t work like that. It does it in reverse and tells you what your takeoff weight needs to be based on the mission requirements. It isn’t as linear as you might think because of the hold at the end etc. I could run it with a 40t payload but where is the evidence this is what QF are looking at? Humans might be time sensitive 2-3hrs over 24hr period but there isn’t much cargo that is.

Fred



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astuteman
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 6:07 am

flipdewaf wrote:
lightsaber wrote:
ElroyJetson wrote:


It is amazing how close fuel burn is for both frames. My question is in regards to the assumed 30t payload.

Where is this assumption coming from? Second, is it certain both frames have the legs to fly the mission at 30t?

And btw....thanks for the information. It is very interesting.

I fully expect the GE engine to have even lower TSFC. It has variable turbine cooling, more precise turbine clearance control, and a rediculous number of cooling looks on the engine. All of that stuff adds weight and cost to the engine, all benefits long haul fuel burn.

The competition is still too close to call. Just a data point.

Lightsaber

Yes, we have a few data points based on models that have some error with assumptions on starting figures that have some flex based on engines that change over time whilst flying through windy conditions during different periods of the year with differing loads. That doesn’t even factor in the cost of the plane the navigation fees, the maintenance, the crew, the ground support systems and training and even then it’s for just one route and realistically QF have to make this work on a network level and even integrate with other carriers. An aircraft could easily burn more fuel to carry lower payload and be a mor expensive aircraft to buy but still be a better option to select for QF.

Still, Top trumps is fun!

Fred


Sent from my iPhone using Tapatalk



Thanks very much for doing this modelling work Fred. One of the few things that make this forum worth visiting regularly is when someone tries to rise above the rhetoric and understand what is actually going on by developing and then evolving a model. Thanks.

Understandably there is a huge focus on SYD-LHR as it is the "holy grail" of ULH flights.
My understanding is that Project Sunrise is about ULH non-stops to all sorts of destinations, not just SYD-LHR - it's actually a principle, not a sector
We seem to be missing a fundamental then in what might be the biggest single factor swaying the decision - which frame is best suited to the balance of those ULH routes, of which SYD-LHR is the longest.

Would you be able to develop your model to show what happens as the range reduces in, say 1 hour, or 500nm increments?
Or if it is simpler, by 2 x 1000nm/2hour steps

Stepping outside the model for a bit, I tend to agree with those who suggest that the Project Sunrise platform will be part of a package of orders.

In this case my opinion is that this will go to the A350XWB.
3 Reasons:-

1. There is little barrier to entry inasmuch as the performance difference does not look to be great over the whole operating window - QF say that both contenders do the job.
2. QF probably hold cancellation charges from the A380's that can be carried over to the A350
3. The A350 is almost certainly way cheaper to procure - it is a) a smaller, lighter frame, and b) will roll off a production line delivering 10-12 frames per month across a whole family, not the 4-5 per month predicted for the 777X. That will bring the same economy of scale advantage to the A350 that the 787 enjoys

Both of those differentiators focus on acquisition cost, and we all know that over the whole lifecycle, that is not a great part of the total cost of ownership (TCO).
However, in my view a myopic focus on the TCO ignores the significance of captial cost as an enabler, for financing, cashflow etc. There is an "NPV" component to capital cost IMO that makes it much more significant than the raw TCO figures suggest.
Put simply, the solution needs to be affordable from the outset.

I think it will be close. And I have no issue with being shown to be wrong - those were just my thoughts.
Both contenders will be amazing aircraft.

For me the A350 will be the more amazing for its ability to cross a "vacuum" in which it is unable to perform mid-range missions, but can then demonstrably undertake missions that are much more challenging. I know of no other frame that exhibits this characteristic ;)

Rgds
 
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cpd
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 6:10 am

musman9853 wrote:
zeke wrote:
musman9853 wrote:
on a somewhat different note, do we know when they might announce the order? Paris maybe?


Two schools of thought

1) never, they are setting AIPA up with the contract negotiations for the blame

2) end of year



Interesting, so I'm assuming Qantas can't have it's pilots fly the route under the current contract then?


I think he is being sarcastic, but it wouldn’t be out of the question to have these planes operated by a different company and flown by non Qantas pilots. The planes would have a QF colour scheme, but also “Operated by” somewhere near the flight deck windows.

Anyhow, back to the technical off-topic discussion that we prefer. ;) and kudos to both Zeke and Fred for their contributions.
 
PlanesNTrains
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 6:12 am

astuteman wrote:
flipdewaf wrote:
lightsaber wrote:
I fully expect the GE engine to have even lower TSFC. It has variable turbine cooling, more precise turbine clearance control, and a rediculous number of cooling looks on the engine. All of that stuff adds weight and cost to the engine, all benefits long haul fuel burn.

The competition is still too close to call. Just a data point.

Lightsaber

Yes, we have a few data points based on models that have some error with assumptions on starting figures that have some flex based on engines that change over time whilst flying through windy conditions during different periods of the year with differing loads. That doesn’t even factor in the cost of the plane the navigation fees, the maintenance, the crew, the ground support systems and training and even then it’s for just one route and realistically QF have to make this work on a network level and even integrate with other carriers. An aircraft could easily burn more fuel to carry lower payload and be a mor expensive aircraft to buy but still be a better option to select for QF.

Still, Top trumps is fun!

Fred


Sent from my iPhone using Tapatalk



Thanks very much for doing this modelling work Fred. One of the few things that make this forum worth visiting regularly is when someone tries to rise above the rhetoric and understand what is actually going on by developing and then evolving a model. Thanks.

Understandably there is a huge focus on SYD-LHR as it is the "holy grail" of ULH flights.
My understanding is that Project Sunrise is about ULH non-stops to all sorts of destinations, not just SYD-LHR - it's actually a principle, not a sector
We seem to be missing a fundamental then in what might be the biggest single factor swaying the decision - which frame is best suited to the balance of those ULH routes, of which SYD-LHR is the longest.

Would you be able to develop your model to show what happens as the range reduces in, say 1 hour, or 500nm increments?
Or if it is simpler, by 2 x 1000nm/2hour steps

Stepping outside the model for a bit, I tend to agree with those who suggest that the Project Sunrise platform will be part of a package of orders.

In this case my opinion is that this will go to the A350XWB.
3 Reasons:-

1. There is little barrier to entry inasmuch as the performance difference does not look to be great over the whole operating window - QF say that both contenders do the job.
2. QF probably hold cancellation charges from the A380's that can be carried over to the A350
3. The A350 is almost certainly way cheaper to procure - it is a) a smaller, lighter frame, and b) will roll off a production line delivering 10-12 frames per month across a whole family, not the 4-5 per month predicted for the 777X. That will bring the same economy of scale advantage to the A350 that the 787 enjoys

Both of those differentiators focus on acquisition cost, and we all know that over the whole lifecycle, that is not a great part of the total cost of ownership (TCO).
However, in my view a myopic focus on the TCO ignores the significance of captial cost as an enabler, for financing, cashflow etc. There is an "NPV" component to capital cost IMO that makes it much more significant than the raw TCO figures suggest.
Put simply, the solution needs to be affordable from the outset.

I think it will be close. And I have no issue with being shown to be wrong - those were just my thoughts.
Both contenders will be amazing aircraft.

For me the A350 will be the more amazing for its ability to cross a "vacuum" in which it is unable to perform mid-range missions, but can then demonstrably undertake missions that are much more challenging. I know of no other frame that exhibits this characteristic ;)

Rgds


I’m expecting the A350 at this point as well, but up-thread someone mentioned that the A380 deposits were going towards A380 refurbishments being carried out by Airbus.
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
Kikko19
Posts: 493
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 7:07 am

astuteman wrote:
flipdewaf wrote:
lightsaber wrote:
I fully expect the GE engine to have even lower TSFC. It has variable turbine cooling, more precise turbine clearance control, and a rediculous number of cooling looks on the engine. All of that stuff adds weight and cost to the engine, all benefits long haul fuel burn.

The competition is still too close to call. Just a data point.

Lightsaber

Yes, we have a few data points based on models that have some error with assumptions on starting figures that have some flex based on engines that change over time whilst flying through windy conditions during different periods of the year with differing loads. That doesn’t even factor in the cost of the plane the navigation fees, the maintenance, the crew, the ground support systems and training and even then it’s for just one route and realistically QF have to make this work on a network level and even integrate with other carriers. An aircraft could easily burn more fuel to carry lower payload and be a mor expensive aircraft to buy but still be a better option to select for QF.

Still, Top trumps is fun!

Fred


Sent from my iPhone using Tapatalk



Thanks very much for doing this modelling work Fred. One of the few things that make this forum worth visiting regularly is when someone tries to rise above the rhetoric and understand what is actually going on by developing and then evolving a model. Thanks.

Understandably there is a huge focus on SYD-LHR as it is the "holy grail" of ULH flights.
My understanding is that Project Sunrise is about ULH non-stops to all sorts of destinations, not just SYD-LHR - it's actually a principle, not a sector
We seem to be missing a fundamental then in what might be the biggest single factor swaying the decision - which frame is best suited to the balance of those ULH routes, of which SYD-LHR is the longest.

Would you be able to develop your model to show what happens as the range reduces in, say 1 hour, or 500nm increments?
Or if it is simpler, by 2 x 1000nm/2hour steps

Stepping outside the model for a bit, I tend to agree with those who suggest that the Project Sunrise platform will be part of a package of orders.

In this case my opinion is that this will go to the A350XWB.
3 Reasons:-

1. There is little barrier to entry inasmuch as the performance difference does not look to be great over the whole operating window - QF say that both contenders do the job.
2. QF probably hold cancellation charges from the A380's that can be carried over to the A350
3. The A350 is almost certainly way cheaper to procure - it is a) a smaller, lighter frame, and b) will roll off a production line delivering 10-12 frames per month across a whole family, not the 4-5 per month predicted for the 777X. That will bring the same economy of scale advantage to the A350 that the 787 enjoys

Both of those differentiators focus on acquisition cost, and we all know that over the whole lifecycle, that is not a great part of the total cost of ownership (TCO).
However, in my view a myopic focus on the TCO ignores the significance of captial cost as an enabler, for financing, cashflow etc. There is an "NPV" component to capital cost IMO that makes it much more significant than the raw TCO figures suggest.
Put simply, the solution needs to be affordable from the outset.

I think it will be close. And I have no issue with being shown to be wrong - those were just my thoughts.
Both contenders will be amazing aircraft.

For me the A350 will be the more amazing for its ability to cross a "vacuum" in which it is unable to perform mid-range missions, but can then demonstrably undertake missions that are much more challenging. I know of no other frame that exhibits this characteristic ;)

Rgds


4) BA and LH has a350 as well in order and might go for the a351 to explore low cost their 'sunrise project' in case QF deciedes to go 778.
 
flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 7:32 am

Kikko19 wrote:
astuteman wrote:
flipdewaf wrote:
Yes, we have a few data points based on models that have some error with assumptions on starting figures that have some flex based on engines that change over time whilst flying through windy conditions during different periods of the year with differing loads. That doesn’t even factor in the cost of the plane the navigation fees, the maintenance, the crew, the ground support systems and training and even then it’s for just one route and realistically QF have to make this work on a network level and even integrate with other carriers. An aircraft could easily burn more fuel to carry lower payload and be a mor expensive aircraft to buy but still be a better option to select for QF.

Still, Top trumps is fun!

Fred


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Thanks very much for doing this modelling work Fred. One of the few things that make this forum worth visiting regularly is when someone tries to rise above the rhetoric and understand what is actually going on by developing and then evolving a model. Thanks.

Understandably there is a huge focus on SYD-LHR as it is the "holy grail" of ULH flights.
My understanding is that Project Sunrise is about ULH non-stops to all sorts of destinations, not just SYD-LHR - it's actually a principle, not a sector
We seem to be missing a fundamental then in what might be the biggest single factor swaying the decision - which frame is best suited to the balance of those ULH routes, of which SYD-LHR is the longest.

Would you be able to develop your model to show what happens as the range reduces in, say 1 hour, or 500nm increments?
Or if it is simpler, by 2 x 1000nm/2hour steps

Stepping outside the model for a bit, I tend to agree with those who suggest that the Project Sunrise platform will be part of a package of orders.

In this case my opinion is that this will go to the A350XWB.
3 Reasons:-

1. There is little barrier to entry inasmuch as the performance difference does not look to be great over the whole operating window - QF say that both contenders do the job.
2. QF probably hold cancellation charges from the A380's that can be carried over to the A350
3. The A350 is almost certainly way cheaper to procure - it is a) a smaller, lighter frame, and b) will roll off a production line delivering 10-12 frames per month across a whole family, not the 4-5 per month predicted for the 777X. That will bring the same economy of scale advantage to the A350 that the 787 enjoys

Both of those differentiators focus on acquisition cost, and we all know that over the whole lifecycle, that is not a great part of the total cost of ownership (TCO).
However, in my view a myopic focus on the TCO ignores the significance of captial cost as an enabler, for financing, cashflow etc. There is an "NPV" component to capital cost IMO that makes it much more significant than the raw TCO figures suggest.
Put simply, the solution needs to be affordable from the outset.

I think it will be close. And I have no issue with being shown to be wrong - those were just my thoughts.
Both contenders will be amazing aircraft.

For me the A350 will be the more amazing for its ability to cross a "vacuum" in which it is unable to perform mid-range missions, but can then demonstrably undertake missions that are much more challenging. I know of no other frame that exhibits this characteristic ;)

Rgds


4) BA and LH has a350 as well in order and might go for the a351 to explore low cost their 'sunrise project' in case QF deciedes to go 778.

I’d have put one VS before LH.

Fred


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qf002
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 8:07 am

I like to compare going for 777s now to going for 747s back in the early-2000s when everybody else was excited for the 77W. I don't think QF will make the same mistake twice.

If the A350 can make the distance then it's is a platform which will serve them well for decades. It's a new generation aircraft, it has multiple upgrade cycles in the pipeline and it's the future-facing option which will appeal to QF's current management as well.
 
moa999
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 8:09 am

Kikko19 wrote:
4) BA and LH has a350 as well in order and might go for the a351 to explore low cost their 'sunrise project' in case QF deciedes to go 778.


BA (or VS) could well pick up the same aircraft as QF, but I doubt the losing manufacturer would go forward with the design without QF.

With the shorter distance could LH be able to make Germany-Aus with off the shelf 350/777, same with NZ to JFK.
 
flipdewaf
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 8:50 am

aryonoco wrote:
Just wanted to thank zeke and Fred for their amazing input to this thread.

It has been one of the most useful threads I've seen here in a long time.

Just a note to Fred, from a computer scientist, if your Excel model is taking that long to run, you might want to look into translating it into something more suitable such as R in future.

I’ve definitely thought about translating into something a bit faster. The problem I have is that it has grown somewhat ‘organically’ to where it is. It started out as a weight estimation tool from my university days and I added a very simple indiced and lift independent drag calculations as I already had the base geometries from the weight estimation part. I wanted initially to be able to do some basic L/D stuff and calculate drag at different speeds for GA aircraft, my intention being build my own aircraft when midlife crisis time comes. I realised that similar what ferpe had done I could easily know a fuel burn based on that drag. I also knew I would be able to utilise a simple ISA table to derive atmospheric conditions and then be able to type a weight and a speed and a height and it would tell me the drag. I then tried to optimise UL/D for any weight and height but realised that my models had issues at high Mach numbers. As I had initially intended it to be for GA aircraft there were exactly 0 parts of the formulas for compressibility effects. This drive me to realise that it isn’t often the pursuit of max UL/D that is required then aligning that to a simple breguet (good first order guess though).

Once I had some ok formulas for compressibility/buffet I realised that I determined that realistically I could apply some rules and step through the process (flight) in 1 second increments ( this makes all the maths much much easier). I know some VBA and this is what it uses. I knew it could climb based on the rules and then step throughout the flight based on if the aircraft would perform within the bounds of rules and performance at the next level before commencing a climb. Throughout the whole process the the drag is calculated and then the fuel flow calculated and then 1seconds worth of fuel is taken from the weight.

I was then able to take a configuration and weight and based on any takeoff weight (either derived from the weight estimator or from another source from an existing aircraft) and fly for a certain distance or time while stepping when the weight reduces enough then landing.

After a debate came up on here (I think the A350 vs 787 range thread) about what is a reasonable amount of reserve on landing I decided I would modify the system to run in reverse for a known end weight and basically add weight as time goes backwards and descend through steps as the weight gets higher. I then effectively put 3 flights together.
1. A diversion flight at a known distance and set height
2. A go around where by it reaches a max height and flies for a certain amount of time
2. The main route of a known distance.

The last piece I added was basically frivolity as I track all my flights I take personally in a database and would add the miles after looking it up on gcmap. I figured i could do the maths of a great circle route as someone kept asking how many miles I flew etc. I found a database of the worlds airports and their long/lat and then use that to determine the range. I simply added that to my spreadsheets and it makes it ok much easier.

The part that takes the time is really calling up the values that I have in tables and allowing in calculations that are still embedded in the spreadsheets to calculate. Those are the first pieces to move to the code if I can. If I was to have to learn a new code and move it to different software I’d put it into JMP stats software as it would allow me run a multivariate DOE and give a full profiler with simple sliders for payload and range and give almost instant results.

Other people get paid for what I do for fun.

I get paid for what other people do for fun.

Fred


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RJMAZ
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Re: Updated: Qantas saying it is almost ready to select Project Sunrise aircraft

Sat May 11, 2019 9:24 am

flipdewaf wrote:
Using my data? We’re you in my house last night?

My model doesn’t work like that. It does it in reverse and tells you what your takeoff weight needs to be based on the mission requirements. It isn’t as linear as you might think because of the hold at the end etc.

Your table gave all the information i needed to calculate it very accurately.

You had two A350-1000 calculations with both 147T and 150T DOW weights. Fuel burns during the flight DOW and payload does not. So a DOW increase or payload increase gives the same result.

A 3,000kg payload increase I can then use your table to see that this resulted in your takeoff weight increasing by only 4,765kg. So that is 1,765kg of extra fuel to carry an extra 3000kg of payload.

As the takeoff weight increased in the A350-1000 63% of the weight can go towards extra payload and 37% must go toward fuel to maintain range. You can do a linear extrapolation providing it is only a small amount.

Your 777-8 numbers showed 10T of takeoff weight remained before hitting MTOW. So that would mean 6,300kg of extra payload and 3,700kg of fuel could be carried to fly the same distance at MTOW.

With 36,300kg of payload in the 777-8 it would have have a much lower fuel burn per kg of payload.

With your best case 157T DOW and 33,000kg of payload you are hitting the 316T MTOW on the right column. The 777-8 still wins on fuel burn per kg of payload.

Now if you increase the MTOW of the A350-1000 to 320T then that would allow 2,500kg of extra payload and 1,500kg of fuel to maintain range. That puts the total payload up to 35,500kg. This equals the fuel burn per kg of the 36,300kg 777-8.

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