Airbus A350-900ULR enables Singapore Airlines to reopen Singapore-New York

By Scott Hamilton and Bjorn Fehrm

Oct. 13 2015, ©. Leeham Co: Airbus and Singapore Airlines have launched the A350-900 ultra long range, the specifications for which we estimated in July beginning with the first of four articles.

The A350-900ULR enables Singapore Airlines to reopen the Singapore-New York “SQ flight 21” that was closed 23 November 2013. It was the world’s longest flight, using an Airbus A340-500 until SQ discontinued it during the more recent high fuel prices that rendered the flight uneconomic.

Update: Singapore has now released this picture through twitter:Changi Newark non stop SQ ad

It will also enable Singapore to restart direct flights to the US West Coast, something that the main competition, such as Cathay Pacific Airways, has been able to offer because of a better geographical position. The A350-900ULR now closes that competitive gap for Singapore Airlines.

Singapore has converted seven of its A350-900s to the -900ULR version, deliveries will start in 2018. The ULR will be in a custom premium configuration of 170 seats, about 60 more than used on the A340-500.


As we described in the July articles (links below), it is a standard A350-900 which is extended with moderate modifications to enable it to fly up to 19 hours. Main changes are an additional five tonnes Maximum Take Off Weight (MTOW) increase from the presently certified 275t variant to a 280t variant. This is paired with wing tank changes derived from the A350-1000 version to allow a maximum of 165,000 l of fuel to be tanked (standard A350-900 now 141,000l, up from 138,000l).

Update 2: We have got further fuel system info from Airbus. The wingbox of the A350 is roomy. There is room for the 141,000l (new info) of the standard A350-900, the 156,000l of the A350-1000 and indeed the 165,000l of the A350-900ULR. It is all a matter of where the fuel computer and its sensors put the volume cut-off for the different fuel compartments and how routing of inert gas etc. gets adapted to the higher levels. So all the same base wingbox, just utilized to different levels.

By using a lighter cabin than normal—the 170 seats–this allows more fuel to be filled, which opens up the 19 hours endurance needed to reach the US West Coast on a windy day or the famous non-stop flight between Singapore and New York.

Singapore Airlines’ need for Ultra Long Haul

In direct connection with our articles around the A350-900ULR, we presented the whole rationale for Singapore Airlines need to fly these long distances. We have now opened up this article series to all readers. It gives the background to the discussions and presents Singapore Airlines different alternatives. Finally it describes why the A350-900ULR is the best alternative.

Here is the article series:

69 Comments on “Airbus A350-900ULR enables Singapore Airlines to reopen Singapore-New York

  1. Hello Bjorn and Scott
    As you tell us in july, here it is the A350-900ULR (light)

    The 170 PAx payload figure is coming out of your modeling ? i’ve seen nothing in the press release and in other media report

    bravo !

    • We have got the 170 seats configuration from Airbus now that the aircraft is released and SQ has ordered it.

  2. Thank you

    So that’s @8700Nm @170PAX with the standard cabin ? or is it a dedicated cabin ?
    From 1650000 l in the A350-900ULR to 1560000 l in the A350-1000 : can we see the impact of the main landing gear bay that is larger on the -1000 ?

    • It is a special cabin configuration for these seven aircraft.

      The fuel is to our knowledge based on the -1000 fuel increase but might use even more of the center wingbox compartment which is for normal purposes the last one you use fully as it increases the wing bending moment the most.

        • Yes. It is all within the standard wingbox as we understand it. The center wingbox piece of the center tank (which contains center wingbox and out to the engines pylons in the wing halves) is the one where it is the least desirable to have a lot of fuel as it generates max wingbending moment at gusts. We think its there that the fuel has been allowed to take more of the physical area available, we are checking this with Airbus.

          Edit: We have now got the answer from Airbus, the wingbox is large, it is all about where the fuel cut-off is put, see update 2 in the article.

      • from the comment about modified fuel routing hardware, I’d wager they add a fuel tank somewhere.
        with “just” 170 pax, there may be room to trade cargo for fuel, or they may simply have room to allow extra fuel in the center tank (with the increase of TOW, probably increasing field length, maintenance, TO costs, maybe even decreasing life cycles)

  3. All right thank you

    Any clue on the aerodynamic improvements announced at the same time ?

    • We are checking as we speak, we think it is tuning of the high lift for take-off and the variable camber for climbe, cruise and descent to the higher weight profile, all software tuning of the FBW. We will see.

  4. It seems the seatcounts assumed in the 3 previous articles were way off as a base for the calculations 😉 I wondered about the 10 abreast 777 cabin for ULH before.

    W’ll now have to see how solid the 777-8 market position is. It’s a “heavy shrink” just like e.g. the A340-500, 777-200LR, A350-800 and 787-8.

    • The calculations are ok. At the time we had no config info, therefore we put the comparison cabins into the articles to make sense of the comparisons. The range figure from Airbus in the press release is for the practical route distance for the Changi to Newark flight, it is not the “show room” range of the variant, this is not known, and also not so interesting as it is a very special variant with a premium heavy configuration. What is significant is the endurance, 19 hours.

  5. It seems the new wide bodies are opening up ultra long range flights all over the place.
    Qantas is looking at establishing a direct flight from Perth AU to London using a 787-9.

  6. The irony here is that this is validating the the concept of Long Thin Routes put forward by Boeing with the Dreamliner.

    • Which does not preclude a trunk hauler like the A380 between megacity hubs, we just need to get to the traffic density where this is a necessity for more airports than LHR and a few others.

      • What I would like to know is the ratio of LTR to MH around the world. Also, there has to be a tipping point where an A380 becomes a necessity. For example when an airline flying between two cities has attained the ideal (or allotted) frequency and is actually refusing passengers due to a lack of capacity. Then the A380 makes sense because the number of customers can be increased while retaining the desired frequency. But I am not sure anymore if the potential is that big today. Certainly less than I had anticipated ten years ago when the A380 flew for the first time. But by the time the A380neo is introduced it is possible that the requirements will have increased at a more significant number of airports, which for the time being remains somewhat limited. It is all tied to the rate of traffic growth: the A380 prospects will continue to improve as long as this rate keeps increasing while the number of big hubs remains relatively constant.

        • Check out Cathay Pacific flights from Hong Kong to Heathrow. On Saturday evening/Sunday Morning they send three 777-300ER in just under two hours! I do wonder why they haven’t got some A380s for that.

          • If those flights are full most of the time it could mean that they have reached that tipping point I was discussing. But the problem with large aircraft is that the bigger they are the smaller the fleet is likely to be. And the smaller the fleet is the less economical it is to operate. In other words to order the A380 is a “very big” decision for most airlines.

          • I think Cathay wants the belly hold freight capabilities of the extra 777’s. Once you have filled up the A380 with passengers and bags, there’s no space left for freight. Maybe an A380 900 would change that.

          • Cathay has 5 daily flights from HKG to LHR. Most are flown with the 777-300ER, some with the 747-400 still in use. And yes, you could assume that a A380 would make sense here. I assume though, that those kind of high volume flights are rare.

            Yes, Cathay also flies 3 times per day to New York. But cutting the frequency there and lose the freight capacity?

            I would guess, they would end up with a too small a fleet on both types less savings on economy of scale, a higher risk, and less flexibility. So somehow I can understand that Cathay has no A380.

    • That long haul Perth-Heathrow non stop could be flown years ago by the A340-200 or 300. Its nothing new.
      The viability of these longer haul flights being introduced has much to do with the lower fuel price, the newer aircraft would make some contribution

    • That is exactly my point. And this concept that AB laughed off while promoting the a380. Maybe the a380 is on its way to the graveyard.

      • You sound like a guy who would love to see the A380 bite the dust. You can discuss its relative merits, or lack of, but you don’t need to send it a death wish. The A380 is an engineering feat that deserves your admiration. But perhaps the problem you have with this aircraft originates from there.

        • I will not disagree that the a380 is an unprecedented feat of engineering, it pushed on how big we can build but the economic are that count. The a380 apart from passengers is constrained in the part of cargo volume. This is particulary highlited when you optimise the cabin space of the aircraft like amedeo. Amedeo has taken 777 densities into the a380. Taking that as our baseline configuration and allowing two checked bags per passenger two LD3 are left for cargo but you have to use the bulk hold in order to fit all the bags. Now stretching the aircraft by 11 frames and using similar densities there space left for 5LD3s again fully utilising the bulk hold. The range will be somewhat constrained to around 6500-7000nm.

        • The day Emirate airlines goes down, the a380 programme goes down with it. That says a lot about how an attractive aircraft it is for other carriers.

  7. I’d expect that SQ will eventually order more A359ULRs in order to open up additional destinations in North America (i.e. SFO, YVR, YYZ, IAD).

  8. Perhaps I missed it, but don’t see an estimated delivery date (year). Has that been disclosed?

  9. RE: Update 2, interesting information about the usable fuel volume, Bjorn.

    Going on a bit of a tangent here – how will this affect the range of a hypothetical simple stretch A350-1100 now that we know there’s extra space in the centre wingbox for additional fuel over the standard A350-1000?

    • Fuel and wingloading is OK for an -1100, fuselage is the length of an 777-9X which is long. The -1100 needs a new engine to compete with 777-9X.

      • Ah right. I take it that the thrust from the present engines is insufficient although the frame allows for higher weights than the present -1000. I think I recall Leahy saying something about needing a bigger fan for such a stretch.

        • A new engine for an A350-1100 that would be 5 percent more efficient than the GE9X engine – with 7 tonnes (9000 litres) higher fuel capacity – and you’d have a very capable A350-1000ULR as well.

  10. Is there room for enough fuel to fly the desired planned payload at four-engine speeds or does SQ presume that if anyone notices longer times than the previous effort that they will not care?

    • There is enough fuel to fly at normal cruise speed, M 0.85 which is faster than before, M 0.83.

      • Bjorn,

        Thanks for the, as usual, well informed and rapid response. The residual question: Is M85 a truly operationally useable speed or are it and its associated Cost Indices so close to Mmo that they are out of the FMS or airline comfort zone.

        • It is an operational speed, the aircraft was designed with this cruise speed. It means you don’t gain much by going slower as your trans-sonic drag rise does not set in at M 0.85.

  11. Update 2: We have got further fuel system info from Airbus. The wingbox of the A350 is roomy. There is room for the 141,000l (new info) of the standard A350-900, the 156,000l of the A350-1000 and indeed the 165,000l of the A350-900ULR. It is all a matter of where the fuel computer and its sensors put the volume cut-off for the different fuel compartments and how routing of inert gas etc. gets adapted to the higher levels. So all the same base wingbox, just utilized to different levels.

    That just goes to show how forward looking Airbus has been when designing the A350. The same thing goes for the landing gear where the MLG on the A359 was clearly designed for growth (i.e. an increase in wheel spacing means larger footprint -and greater wheel spacing decreases ACN number, which means less impact on the pavement by the aircraft).

    The distance between the wheel axial centerlines (wheelbase) and the wheel disk centerlines are, on the 788, 789,A359,77W and A35K, respectively:

    788: 1.46m and 1.3m
    789: 1.51m and 1.52m
    A359: 2.04m and 1.735m
    77W: 2.93m and 1.40m
    A35K: 2.8m and 1.397m*/1.474m**

    *Front and rear wheels
    ** Centre wheels

    Clearly, the centreline between the wheel disks is significantly greater on the A359-MLG than on comparable aircraft. That’s part of the reason why an A359 will be able to take-off at 280 tonnes while having only two 4-wheel main gear bogies.

  12. Dear Bjorn:

    Does this mean that by using this additional tank space, the range of the standard A350-900 and A350-1000 can be increased in a straight forward fashion for those airlines that need just a bit more range…like from the Middle East to LAX?

    • The first key change is the increased MTOW with 12t over the standard version giving you an extra 2 hours endurance, then the empty weight gain from a 170 seat cabin and ZFW gain from 170 pax+bags giving you at least another hour if not two and finally the extra fuel avoids you getting fuel capacity limited when you fly all these hours. You can calculate with gaining 490nm per hour extra still air range, so it adds up.

  13. Just because the A359 ULR can technically fly routes of 8,700 nm doesn’t mean it makes economic sense to do it. Never in the history of ULR flying has any airline ever made a profit when flying these types of routes over a sustained period. Anyone that works in airline fleet management will tell you that all that extra fuel you carry plus additional flight staff $$(both attendants and pilots) plus additional supplies all add up to non-profit generating weight that limits the amount of profit generating passengers and belly cargo that you can carry. The biggest factor is the price of fuel, right now its reasonably low but if it ever goes back to anywhere near the obscene levels seen just a few years ago than Singapore Airlines will drop these planes just as they did with the 345’s. As i said earlier, yes we can fly that far, but does it make sense to do it?

    • Which is why the airline experimented with the 100-seat all-Business configuration in the later days of the A345 era. Unfortunately, the cabins were seldom full, unlike the earlier phase with the mixed-Economy/Business configuration. It’s always a fine balance between multiple factors: Weight, number of passengers, class configurations, etc.

    • Very long range Aircraft carry lots of fuel, hence the fuel consumption of the Engines are very important. A few % makes big difference in tons of fuel at take-off as per the Breguet equation. You also gain Aircraft Life and reduce maintenace cost by reducing the number of cycles. The GE9X and RR Advance will maybe be so good that ULR Aircraft become more common and the UAE hubs will loose traffic.

  14. Pingback: SIA makes POWER-ful PE statement; will it extend to A350-900ULR? - Runway GirlRunway Girl

  15. What’s the split of the cabin? How many economy seats (or is it premium economy only) will there be in the cabin, how many business? Or even some first?

    • Singapore Airlines has not released the class configuration yet. But I will bet with my last dollar that you will definitely see some Business seats. Having an all-Economy cabin just isn’t economically viable. A Business ticket generates about five times the revenue of an Economy ticket, at less than five times the cost. In addition, the SIN-EWR route will see financial heavyweights as its frequent flyers. These guys expect nothing less than Business. I predict a 100J/70Y cabin.

      • Another possibility: 8F, 42J, 35W (7 abreast), 88 Y (8 abreast)*.

        Same standard as Y on SQ’s A388s – 20-inch wide aisles, 18.5 – 19 inch-wide seats + 2 inch of additional pitch (i.e. 34″ vs. 32″).

        • Right. Seems like they would do best to try to dial in the best range of the mix of market demand, similar to United PS configurations or something like that.

  16. For what its worth, one of the A350-900 test birds has been sitting in Anchorage for the last two days.

    Seems like it is broke but if any of the sleuths could find out?

    • Well its still stuck in Anchorage.

      Bunch of people come out, noises are made then quits and they all go away.

      If that is A350 reliability the 787 does not look so bad!

      It does look nice with those red engine covers.

      Funny looking nose though.

      • Well I think it left Anchorage. No track in or out but it was firing up engines today, accompanied by two airport fire trucks and another emergency vehicle as well as two Airport Police vehicles.

        Too bad, it was getting to be an interesting fixture

  17. Boeing has lost the deal just because of the timing of the 777X EIS.
    The 777-8 is the more capable aircraft because it can offer the same range with more payload just out of the box. I know people will argue that its a “heavy sink like the 787-8,777-200LR” but those heavy sinks are flying and bringing in a lot of revenue for their operators.
    Besides, it can start as a heavy sink but will shade its weight as has been the case of the 787-8.
    There is nothing impressive with this A359 ULR, with only 170 pax even the lean mean 787-9 with minimal modification to increase fuel capacity could do it.

    • As I indicated in my comment up-thread, the 787-9 is maxed out MTOW-wise. The MTOW of the 787-9 started out much lower than what it is today. MTOW growth: 221.1 (metric) tonnes (Jan 03), 230 tonnes (Nov 03), 244.9 tonnes (Oct 05), 247.2 tonnes ( Apr 08) and 253 tonnes today*. In short, Boeing seems to have used up all the extra 787 design margin during the development/delays of the programme.

      Thus, the MLG can’t grow by much, if any, and the MLG-bays cant’accommodate a larger MLG. Therefore, there will be no 787-9ULR – unless, of course, Boeing would choose to develop both a 787-10ER version and a 787-9LR version – both sharing a larger wing and bigger MLG. However, the MTOW of the 787-8 could conceivably be increased to that of the 789/78X. Then you’d have a 788ULR.

      As for the 777-8X; please do keep in mind that it’s going to use an engine with a about 5 percent lower fuel burn than the TXWB engine on the A359. Still, the A359ULR will be more efficient. That’s a risky proposition – entering market 4 years later than its competitior, while burning more fuel per seat – and the A359ULR is nearly identical to the baseline A359. Not so for the 777-8X.

      Now, imagine what would happen if the A359ULR would be re-engined, a decade hence, with an engine having 5 percent lower fuel burn than the GE9X engine on the 777-8 – an engine that could be derived from an all new A350-1100 engine (EIS 2025?). It seems to me, therefore, that with the 777-8, Boeing might be facing the risk of an abbreviated production-run. In short, it might be too little too late – as you indicated.

      * (Page 12)

      • Yes, that is interesting how the A350 gear has a bigger spread to take more loading.

        I figure add belly tanks to the 787-9 for more range with less payload would be the cheapest option for the 787.

        I don’t actually see much of the purpose of the 777-8, other than the base for a future freighter. I suppose it can carry a big freight payload on a 14-16 hr flight, if that pays the bills. For ULR, I figure they would be better to add belly tanks to the 777-9, and take advantage of the extra floor area for lots of high dollar flat bed seats and crew rests and configure it with about 200 seats.

        • I think the 777-8X does a different job from the A350-900ULR. Its job is to take a full load of passengers and freight the full distance. The job of the A350-900ULR is to take a light load of passengers extra distance. The 777-8X is too much plane and burns too much fuel to do the ULR lite load job efficiently. But the 777-8X will do a great job as a workhorse for runs between the middle east and west coast America, which is why the ME3 have bought a bunch of them.

      • I don’t think the a350ulr will be attractive many airlines. I wonder if such ultra long routes are still profitable if the load factor is below 75% or even 80%.
        You cannot therefore guarantee that the 350ulr will be flying of the shelf and it cannot be also have an abbreviated production-run.
        The aircraft should be called “a350ulr-limited edition” due the small number of items that will be sold.
        All the negative talk about the 777-8x is just premature as the design freeze has not happened yet and you have no idea about what other improvements boeing can make before then or even after EIS.
        A fully loaded 777-8x will generate more revenue doing an ulr trip but the “a350ulr limited edition” will generate less revenue doing the ulr trip.

  18. Pingback: Singapore Airlines launches the A350-900 ULR... but will it work? - Economy Class & Beyond

  19. Leehamnews has forgotten to say that this version is NOT actually launched. Airbus needs more customers to launch the version. The most possible customer because everyone else has chosen the 777-8X or they do not need all this range is Vietnam airlines. But vietnam airlines has a MOU for 8 777-8X and 8 787-10. That means that either airbus finds more customers and proceeds or SIA of non-stop flights to the US in 2018 will fade away

  20. With such a massive cost to lift that fuel such an enormous distance, I wonder when in flight refueling will be introduced to commercial flights. This way, planes will only lift fuel for over water legs, and top up over land. Surely the cost of the infrastructure to facilitate this will easily pay for itself vs having to haul fuel 8-9 hours.. just to fly the next 9-8 hours. I shudder to think what the cost of the fuel is on the second half of the journey when you consider transport costs and opportunity costs.

    • 😀 I shudder to think what the cost of the fuel used by the tankers carrying the fuel, next to the overall operating cost of tankers & its crews etc. the “infra structure”.

      Maybe a large drifting airport in the middle of an ocean is more feasible? You can build it in a particle place, move it, turn the runway, handle existing fleets 😉

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