It nearly could.
The biggest problem is the 787-9 hits maximum fuel capacity at exactly 8200nm. So it can not use any of that extra MTOW increase for fuel without an aux fuel tank.
Now with the 777LR and A350-900 ACAP documents when you add an aux fuel tank it extended the upper first line and eliminates the kink at the bottom of the payload range chart. So we can predict exactly the payload the current 787-9 could take with just an aux tank.
The standard 787-9 with 254T MTOW could carry 38,000lb of payload 9200nm. That is 170 passengers. It requires 11,000kg of extra fuel in an aux fuel tank in the hold.
Now a 6T MTOW bump to 260T would mean 3.5T of extra payload and 2.5T of extra fuel. This brings the passenger count up to 200 passengers. The aux fuel tank would need to then hold 13,500kg of extra fuel. Engine thrust would not be an issue because the 787-10's engines are rated to 5,000lb of extra thrust than the 787-9's.
When you start to get seating density this low you lose most of the gains due to the weight of the recliner bed seats. So it might only be able to fly 160-170 passengers on a standard day. The 787-9ER would be burning 20% more fuel per passenger than the 777-8. It is unlikely the 787-9ER would get selected.
The thing that no one has mentioned yet is a 6T MTOW boost on the 787-8. This would actually be the best choice for project sunrise in my opinion. The smaller aircraft gets a bigger performance boost with any given MTOW increase so the 787-8's range then exceeds the 787-9. The 787-8 would not even require an aux fuel tank. Right now a standard 787-8 could fly Sydney to London with 90 passengers. A 6T MTOW bump would allow 130 passengers in a low density 4 class cabin.
130 passengers might not sound a lot but JAL has 161 seats on their long haul 787-8'shttps://www.seatguru.com/airlines/Japan ... 800_B.php#
So looking at that layout if Qantas fit two rows of 1-1-1 in that front part they are already down to 149 seats in a 4 class cabin. So really 130 seats isn't that crazy. This 787-8 would still burn 20% more fuel per passenger compared to the 777-8 but the main advantage of the 787-8 is lower risk when opening new routes in Europe.
Obviously the ultimate aircraft for project sunrise would be the 787-8ER that some members dream of. A standard 787-9 built with the 787-8 fuselage retaining the 254T MTOW. This beast could do any route in Europe with 200+ passengers even on a bad weather day.
I actually think the 254T 787-8ER is coming. Long term my prediction with Boeing is that the 797 launches and most of the A330's and early 787-8's that are flying short medium haul routes get replaced by 797's. The 787NEO then comes out in 10 years time and the 777X sales die in the ass. Boeing launches the 787-11 which has the same range at the current 787-10. The 787-8 then becomes a simple shrink of the 787-9. Boeing then launches the hybrid electric 737 replacement in 2030. The 797 takes the 737 routes over 2000nm allowing the hybrid aircraft to do the short haul.
First I enjoyed your post. Just bringing the 788 to 789 MTOW is a quite capable aircraft. If the 6T MTOW boost is possible, that is tremendous range.
There is a c-series, err... A220 thust bump that only occurs after a certain flight speed (100 kts if I remember right). That style of thrust bump, would allow tremendous thust on the 788 giving absolutely legendary takeoff performance. That thrust bump gets around rudder moment arm issues at high thrust. I would select a higher airspeed for the 787, but that is just my design optimization.
I am one of those 788ER a.nut fans.
A good challenger to these 787-8/9ER would be the A330-800ER. From a structural point of view, Airbus has the toolbox to make it a 275t (or even 276.5t) aircraft: it's the A343E (*), more specifically its wing and its center landing gear. This is to say that Airbus wouldn't need to spend a lot in redesigning the A338 to make it a 275t aircraft. The A338ER could also take advantage of the fact that it would be designed for a relatively low MLW owing to its light payload.
Now let's say that the empty weight of the A338ER would be 3t higher than the A338. This would allow (21t minus the weight of the expected aux tank) of extra tankage in the ER with the baseline passenger load of the 251t A338. This alone would probably bring the range of the ER to 9400nm (feel free to refine this rough estimate). Trading a couple of tonnes of payload for fuel would push the range beyond 9500nm. Going by these rough estimates, the A338ER could fly a 20t payload over 9500 nm. This is exceeding the payload.
Note that the A338 has 10t more internal fuel capacity than the 787 (and the usable fuel capacity on the A340 was even 1t greater and I would think that it has more to do with the respective fuel pumps positions on the A330/A340 than the available fuel volume itself. If it's the case, this 1 extra tonne of internal fuel could be recovered). Even accounting for a fuel burn a few percent greater than the 787-9ER, the A338ER might get away with a smaller aux fuel tank, translating into less weight penalty induced by the aux fuel tank itself. With an aux fuel tank limited to say 7.5t instead of 13.5t for the 789ER, the weight saved on the aux fuel tank could amount up to 1t (going by the 0.4t of the A320 ACTs). This is not negligible as it would translate into about 0.7t fuel saving over a 9500 nm flight (considering that a 260t 789ER would burn about 110t of fuel to haul 150t over 9500 nm). About the 788ER, it's not clear to me how it could avoid any aux fuel tank if the 789ER would need a 13.5t aux fuel tank. Something doesn't add-up.
I see two potential issues with the A338ER though:
1) It would probably require more thrust than the 251t variant (**). If it's the case, it's not sure that RR would be very motivated to provide a more powerful variant of the Trent 7000. This being said and although I'm leaning towards the A359XLRF (316t MTOW with the A359 fuselage length) for the next Airbus freighter, a 275t A338ER could be a very interesting freighter as well and could be an incentive to develop the new engine variant.
2) the lower cruise speed of the A330 vs the 787 speed is placing the A330 at a disadvantage for the Sunrise mission lengths.
(*) Interestingly, the MTOW of the A343 is now quoted at 276.5t on the Airbus website: https://www.airbus.com/aircraft/previou ... 0-300.html
. I was not aware of these weight variants until today (WV028, 052 and 053).
(**) By comparison with the A340, I'm actually puzzled by the fact that a 72 klbs engine thrust is sufficient for a twin-engine aircraft with a MTOW of 251t. In an engine failed configuration, it is left with 72 klbs where the A340 was left with at least 93.6 klbs (with the CFM56-5C2). Hence I'm not sure of what is the actual driver for the A330 engine thrust but in any case the higher the MTOW, the higher the engine thrust requirement is. I take note of the possibility to consider a thrust bump during the take off run to mitigate a possible lack of rudder authority at low speed.
Tomcat's idea of a 338ER could pencil out from an airframe standpoint, but I see two issues:
1. The thrust piece you mentioned (though for these routes, longer runways at LHR and SYD might work at a lower thrust setting)
2. Fleet oddballs: putting the 340 CLG on the 330 will likely require retooling of parts that have been out of production for a decade, as well as local reinforcements to mount it. If Airbus and customers don't see the value in doing a 359 with -1000 gear and wing, then this likely won't fly for the same reason.
Regarding the 788ER, that's a possible option, I'm curious to know how much of a structural weight penalty you'd pay over the standard 788, and to what extent some of the increased commonality with the 789 (gear legs, wheels, etc.) would offset that.
To Lightsaber's point about vmcg issues on the shorter fuselage with the more powerful engines, if you go from 64k to 76k, that's a 16% increase in thrust. Given that fin and rudder effectiveness scales as the square of airspeed, and your thrust moment is in the same spot, your vmcg as a function of thrust in an OEI scenario will scale with the square root of your airspeed, so you can expect that the 788 with 76k will have a vmcg about 8% higher. On the takeoff roll, the engines can be set to 64k until vmcg(64), then upon hitting that speed, progressively spool up to vmcg(76). As you're accelerating, you're also losing some thrust due to the lapse rate, so you can start sneaking in a few more % N1 on the roll, then go aggressively in what we can call the "vmgc range" until you're at the full allowable N1. Without spending the rest of the day running numbers, I'd bet you can start dialing it up well before 100 kts. Without the tailstrike issue from the 78X, you can also rotate to a higher pitch setting, so the vmcg software fix should probably result in similar overall runway performance numbers. My only question now is how the regulators would look at it....
The 388 and 788 discussions might be moot anyway from a CASM standpoint, as zeke pointed out, but it's fun to look at the what-ifs a bit.