Hello All,
After looking at small and mid-sized widebody aircraft, we now focus on the large ones. We will analyze the A350-1000, both 777X variants, and the previous-generation benchmark for the category: the 777-300ER. How do new-generation aircraft stack against the best-seller Boeing twin?
Even more caution on the comparison
The words of caution from the previous post remain valid. There are also a number of other assumptions that have been made in building the payload-range diagrams in this post:
For the 777-300ER, the payload-range diagram published in the airport manual uses a cabin configuration significantly lighter than modern aircraft. This blog re-used the diagram but adjusted it so it matches the point of the official range published by Boeing: 392 passengers (40.0 metric tons) at 7,370 nautical miles.
For the A350-1000 NPS with a 322 metric tons MTOW, Airbus announced a nominal range of 8,900 nautical miles. We assumed an increased maximum structural payload from 67.2 to 68.9 metric tons due to the weight reduction. We matched the passenger payload (34.6 metric tons) at 8,900 nautical miles. It results in an aircraft capable of carrying 6.4 metric tons more for a given range.
Building 777-8 and 777-9 payload-range diagrams require even more assumptions since none have been published. We have made the following assumptions:
- A maximum structural payload of 70 metric tons for both 777X passenger variants;
- Match the following points on the payload-range diagrams per the range published by Boeing: 43.5 metric tons at 7,250 nautical miles for the 777-9 and 40.6 metric tons at 8,750nm for the 777-8.
Payload-range diagrams
Below is the payload-range diagram of the four aircraft and their enhanced MTOW variants in dotted lines:
With the following payloads at various ranges:
| Range | 777-300ER | A350-1000 | 777-9 | 777-8 | A350-1000 HGW |
| 5,000 | 65.0 | 67.2 | 69.9 | 69.9 | 68.9 |
| 5,500 | 65.0 | 67.2 | 67.8 | 69.9 | 68.9 |
| 6,000 | 60.6 | 62.0 | 60.9 | 69.9 | 68.3 |
| 6,500 | 53.2 | 56.1 | 53.9 | 69.9 | 62.5 |
| 7,000 | 45.9 | 50.3 | 47.0 | 64.5 | 56.7 |
| 7,500 | 38.5 | 44.5 | 40.0 | 57.7 | 50.9 |
| 8,000 | 38.7 | 33.1 | 50.8 | 45.1 |
Tight on MTOW for some missions
The 777-9 has a little more payload range than the benchmark 777-300ER. However, due to its larger capacity (426 vs. 392), the nominal range is lower. It means the 777-9 has less capacity than the A350-1000 with 316 metric tons MTOW. The gap widens even further with the HGW A350-1000 with 322 metric tons MTOW.
The 777-9 payload range is adequate for most airline missions. However, it could be tight for some missions from the Gulf (Los Angeles, Sydney, Auckland) or trans-Pacific where airlines would want to carry more cargo. The A350-1000 can carry more freight on those missions.
Expect Boeing to increase the 777-9 once it enters service from its current 351.5 metric tons. Since the 777-8F will have a 365 metric tons MTOW, it should be feasible. It should also not be a problem for the GE9X to handle a small MTOW hike.
Engine durability issues
The A350-1000 currently has a better payload range than the 777-9. With a lot of existing 777-300ER operators already using the A350-900, this blog showed that the larger A350 variant has a good shot at winning more campaigns.
However, something could stand in the way of more commercial success for the A350-1000: the durability of the Trent XWB 97. While the Trent XWB 84 on the A350-900 does not have durability issues, the A350-1000 variant has issues. Emirates’ Tim Clark publicly criticized the Trent XWB 97 issues, preventing an order for the A350-1000.
Rolls Royce must improve the Trent XWB 97 to win more A350-1000 orders. Airlines are fed up with the engine durability issues on the Trent 1000 and the latest-generation single-aisle aircraft. Some airlines could order the 777-9 instead of the A350-1000 for these reasons if it is a worse network fit. The engine durability issues could also negatively affect the A350F sales against the 777-8F.
There is no guarantee the GE9X will be better at entry into service. With the severe program delays, 777-9 delivery slots aren’t available until late this decade. Rolls Royce must use this time well to improve the durability of the Trent XWB 97 that equips the A350-1000. Otherwise, Airbus will be severely handicapped in its goal to reach market share parity with Boeing in the large twin-aisle market.
EPSILON AVIATION 
The more I look at your graph and table the more I wonder why on earth is Emirates willing to pay some extra 50 mln usd per plane for each 777-8 rather than a A350-1000HGW. And for no less than 35 examples! Fuel consumption is 6.5 tons/h vs 5.5 tons/h, so for a 15 hour mission that is 15 tons of additional fuel, or some $15,000 per trip, just to carry a paltry additional 2 tons at long ranges, which with luck may bring an extra $2-3,000 in revenue. With more maintenance, an aluminium fuselage rather than composite, bigger and costlier engines to service, etc. With these numbers Emirates will be kissing goodbye to some $4 mln per plane per year, or over $100 mln per year for the subfleet in operating costs, plus the additional capital expenditure.
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Just have a look with gcmap, between 6000nm and 7000nm lies the East coast of Aussie, majority of North America, and Brasil. This is where the 778 has the largest payload lead over a 322t 35K. If STC decided the ~10t extra payload can pay itself so be it. After all majority of those planes would be dedicated to those destinations.
But Emirates is as much a rule as the exception. Over the years Airbus has significantly strengthened 35K to match and exceed 77W, and that seemed to paid off. While Emirates doesn’t seem impressed with the upgrades, it’s sufficient for the others, including those customers with more challenging scenarios. Airbus just don’t want to build another Emirates’ plane at the cost of mass.
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On second thought, perhaps there are a few numbers that may have to be reviewed. 777-8 and 9 have the same MTOW. Yet the former is clearly lighter. How much? Comparing OEW and lengths of A350-900 and 1000 we see that OEW changes at a rate of 1.8 tons per meter of length. Being 777-X a bit wider we can use 2 tons/meter. With a length difference of 5.8 meters shorter we can estimate that 777-8 will have a 12 ton lighter OEW, which at parity of other parameter enables a payload increase of said amount. Then 8 being smaller, it has less wetted area, hence lower fuel consumption. Rather than 6.5 tons/h we might consider a modest deduction of 0.2 tons/hour, which for an 8,000NM mission or 17.8 hours will represent a saving of 3.6 tons of fuel at said range. So at 5,000NM payload would be 70 ton + (0.2 tons/hour x 11 hours) + 12 tons or 84.2 tons, and at 8,000NM 47.4 tons + 12 tons + 3.6 tons = 63 tons payload. In this case Boeing would be clearly ahead.
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Hi Luis I agree that my payload-range estimates for the 777X are probably far from perfect. It will be easier to estimate the 777-8 once the payload-range diagram for the 777-9 is published … hopefully in 2 years. I assumed that the 777-8 could take 40,3 metric tons payload at 8500nm. As you say that figure might be valid for 8750nm. Hard to be certain.
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I remembered many estimated the original 778 with an OEW similar to 77W?
It was shorter, but with the extra weight of GE9X the aircraft shouldn’t be much lighter. The wings per area is lighter but bigger, so no weight savings expected either. It should be slightly heavier now due to the stretch though. For 779 many expected ~184t, based on advertised range and weight difference between older 777s. Airbus also claimed 35K a 35t OEW advantage over it.
In terms of fuel burn, given Qantas’ (and in lesser extend Qatar and Ethiopian) preference towards 35K, 778 probably can’t beat 35K on that front, both per seat and per trip. Many expected similar or slightly better per seat cost over 35K, and trip cost proportionally higher. Not good enough to win those with no short of capacity, but good enough for those wanting the big shiny frame to stay. Emirates and Lufthansa said “as expected”.
It seems many (including Epsilon?) based on similar assumptions. I would consider these educated guess. I just don’t understand why Boeing remains tight-lipped. 779 has been test flying for years, you just can’t really make dramatic changes at this point.
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I updated the diagram with the 40.3 metric tons payload for the 777-8 at 8750 instead of 8500nm. Let’s face it though it is guess work and speculative.
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Fully agree that without payload-range diagrams from Boeing all is a guesstimate game. I am aware that if my calculations were true and correct all airlines would be elbowing their way for advanced deliveries, which is far, far from the case. Still I believe that the lower OEW of 777-8 plus a somewhat smaller fuel consumption should improve its performance further over this second version In the meantime, only Boeing and Tim Clark know how the cookie really crumbles.
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I’d expect 35K having higher payload on longer range, but I didn’t expect the gap is as large as 10t at some point. For routes like HKG-JFK, the difference could be as big as some cargo vs nothing.
If that’s really the case then 779 at 351t is actually a worse cargo plane for many. On longer transpacific routes the extra volume over 35K is useless without sufficient payload to actually carrying it. But on shorter transatlantic routes you have 78J.
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Correct the 779 is tight on MTOW for the trans-Pacific routes if you want to carry meaningful amounts of cargo. This is particularly important for Korean Air, the most promising remaining potential 777X customer, on the LAX-ICN route
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