Options for Singapore Airlines to operate direct flights to the US.

By Bjorn Fehrm

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July 20, 2015 © Leeham Co. Last week week we wrote about how Singapore Airlines is in talks with Airbus and Boeing to find a suitable solution for its Ultra-Long Haul airplane needs. Now we go deeper into the subject, looking at the background to the need, the aircraft options and their economics.

We also check if the different aircraft options could open the famous Singapore-New York route again, this time with acceptable fuel economics.


  • We explore SQ’s options for US direct traffic, looking at possible aircraft and their fuel economics.
  • The A340-500 flight to New York was stopped because of to high fuel costs. We show what the fuel consumption would have been with the 777-200LR.
  • Should Airbus decide to launch the A350-900LR a specially equipped version could re-open the famous route. We show how and with what fuel gains over A340-500 and 777-200LR.

Singpore Airlines (SQ) is one of the world’s premier carriers. It has a good vantage point geographically to serve its home market Asia but is not ideally placed to feed this market with traffic from Europe or Americas, Figure 1.

SQ's network

Figure 1. Singapore Airlines network cities world wide. Source: Singapore Airlines.

The distances are long, Singapore is placed right at the tip of the Mallya Peninsula. The result is that SQ needs longer range aircraft to feed its extensive Asian network, especially for feeds from the American continent.

For Singapor Airlines the feeding of traffic from Europe to its Asian network requires 12-14 hour flights from e.g. London to Singapore for then to continue to e.g. Jakarta or Sydney. The flight from Europe being over 12 hours requires a true long-range aircraft like a 777-300ER or A380-800 on the route. The subsequent hop to final destination in Asia would be within six to eight hour flights which are within the capacity of aircraft like A330.

To capture direct traffic from Americas creates a bigger problem. Singapore lies far from the American continent, Figure 2.

Figure 2. Great Circle distance from Singapore to key destinations. Source: Great Circle Mapper.

All flights go beyond 15 hours which is the typical practical standard for long range aircraft like 777-200ER, A350-900 or 787-8. A 787-9 or 777-300ER adds about an hour but would be squeezed on any route but San Francisco or Los Angeles.

Singapore Airlines main competitors are many times better placed. The Middle East carriers have Europe within eight hours and US east coast within 12. Only US west coast is taxing the max range of their 777-300ER, 777-200LR or A380. Cathay Pacific from Hongkong has all key areas better accessible than SQ. Europe is reachable within 10-11 hours. US, both West and East coast, within 15 hours and Cathay has the same access to South East Asia as Singapore Airlines.

It is therefore no wonder Singapore Airlines is searching for a practical aircraft that can serve major portions of the Americas with direct flights. Such an aircraft need to have a standard range of at least 8,500nm as bad weather will require longer alternates than the 200nm included in the standard range calculation. Westerly winds when flying back from US West coast will also tax the aircraft’s range. It will add an additional 10% to 15% to the still air range needed over the ranges shown in Figure 2.

Suitable aircraft

The only practical aircraft for such distances flying today would be Boeing’s 777-200LR. It has a range without extra tanks in the rear cargo bay of 8,665nm. With extra tanks (max of three) it can fly up to 9,400nm carrying 301 passengers.

Singapore Airlines (SQ) previously used a specially equipped A340-500 to fly to the US East coast, landing at Newark, close to Manhattan. This aircraft carried only 189 passengers in a configuration of 64 “space bed” business in 2-2-2 and 117 premium economy seats in 2-3-2. Later this was changed to 100 all business seats.

The great circle distance for the flight is around 8300nm but the aircraft took a longer route of around 9000nm to seek favorable tail winds for the flight. To New York the route would go via Russia over the north Pole or North Pacific. Going back it would chose the most favorable route to avoid the prevailing Westerly winds over the Pacific, often going in the other direction via North Atlantic back to Singapore.

By avoiding headwinds and only loading the aircraft to 189 passengers the original version of A340-500 that SQ had could fly the route. The aircraft was rated at 8670nm while carrying 313 passengers. To enable the route the payload of 31 tonnes has to be reduced to under 20 tonnes by reducing the seating to below 200. It took between 18 hours 30 minutes and 19 hours to complete the flight, partly due to the Mach 0.83 speed of the A340 series.

An A350-900LR would have a bit shorter range than the SQ A340-500, around 8500nm with the same nominal passenger load of 313 passengers but it would gain far more range when equipped with the same seating style as the A340-500. By reducing passenger count to 189 in business and premium economy the A340-500 gained around 400nm whereas A350-900LR would gain 1,200nm going from 313 passengers to 189 in a 64 Business lie flat and 125 Premium Economy configuration.

The reason for this big difference is in how much one gains from each tonne of passenger weight which is traded for fuel but also whereas the aircraft are flying in their fuel limited state when going to these long ranges. For A340-500 the long range meant the aircraft was flying into fuel limitation which resulted in only 45nm gained per tonne of payload which was traded. Could the aircraft have loaded more fuel in larger tanks it would have gained 75nm per tonne.

The A350 gains 120nm per tonne as it can trade passengers for more fuel with no risk of running into fuel limited condition. It would gain space for additional fuel by taking the tank configuration from A350-1000, opening up the tank area from standard 138,000 liters to 156,000 liters.

Boeing’s alternative for the route, the 777-200LR, would gain nominally 400nm in range over its present 8,650nm when going from its standard configuration of 301 passengers to 189 passengers. The trade is here 45nm per tonne as the aircraft is in its fuel limited range. If we equip 777-200LR with 3 extra tanks in the aft cargo bay we avoid this fuel limitation and would gain 800nm in range compared to when carrying its nominal 301 passengers. The trade is then 90nm range per tonne of passenger weight.

Economics comparison

If we compare the economics of flying these three types on the Singapore-New York route, ca can use e.g. 8500nm as the still air distance. We expect the additional range we need to cover the distance to come from our routing as described before, at all times seeking the most favorable winds.

Of the three the A340-500 consumes the most fuel, 150 tonnes or 800kg per transported passenger. The 777-200LR would consume 122 tonnes or 650kg per passenger. Finally A350-900LR would have taken 95 tonnes at 500kg per passenger. The differences are significant and show how the aircraft belong to different generations. The 777-200LR came three years later to the market than A340-500 in 2006, the A350-900LR would add another 10 years minimum to the in service date of the -200LR.


On such long flights fuel cost is the dominant costs for the operating economics. As can be seen a stretched version of the latest generation of airliners have clear advantages in the important fuel consumption area, thus making such flights possible.

The Boeing 777-200LR is the aircraft presently designed for the distances involved and Singapore Airlines operate a large fleet of 777 (but not the -200LR version). The problem is that it belongs to a generation of airliners which is now being replaced by more fuel economical ones from Airbus (A350) and Boeings (787).

Boeing would come in the same consumption per passenger window could they stretch the range of its 787-9 but its wingtanks cannot be expanded and there is no certified additional cargo bay tank system at present. An additional complication in the SQ case would be that the mainline carrier doesn’t operate 787s, these are placed at its subsidiary Scoot. While it would be less of a problem for maintenance (Scoot maintenance can be used), flight and cabin crew certification for a limited subfleet of 787 would be a problem for SQ.

It remains to be seen how Singapore Airlines will decide, a stretched A350-900 would enable operations to the US and a special reduced seating version would even enable the famous Singapore-New York flight with acceptable fuel economics. Singapore could also elect to stay with what they know, the 777 series, by opting for 777-200LR. It could certainly do the job at a more acceptable fuel bill than A340-500.

8 Comments on “Options for Singapore Airlines to operate direct flights to the US.

  1. Hello Bjorn

    8500 Nm and 90t of fuel for A350. Considering reserves and so on you got to 95-100t fuel at take-off.
    With 200 PAX it seems you’re still within the current basic MTOW (and for sure within the 275t increase MTOW)
    Is that it ?

    • Hi Poncho,

      yes with 95t consumed you would start with a TOW of 261t on this day. Another day with less favorable winds or bad alternates it can be very different. Also it might be that SQ wants to run a less extreme config, who knows. The full 280t will be needed for normal cabin operations to US, SQ might have a normal cabin to New York as well, just block of seats to get the range needed for the day. I did it like this to get everything comparable, more of an apples to apples example than a realistic config.

  2. Yes Still the 275 t version is certified. sO that leave with @200 PAX something like 14t margin.
    I only say that right now there’s an A350 that can be delivered in end 2015 that can do the job with “normal cabin” with blocked seat if they want to try…
    By the way LAX-SIN on bad days is almost as demanding a SIN-JFK (I use LAX-MNL as a base point -> http://avia.superforum.fr/t1532p560-airbus-a350xwb-partie-3#66108)

    My only problem is : who will use A350 275 t ? Hope the answer is not : nobody :d
    By the way, what is according to you the time frame for certifying 280 t variant ?

    • Airbus has always a large number of Weight Variants (WVxx) certified for their aircraft, look at their ACAPs. It might have been that they discovered that the certified WVs was not the best they could do with present airframe to respond to SQ’s needs.

      It could be that when certifying the aircraft they included what was sensible based on their 138,000 liters fuel limit, then airlines asked whether that was the max the basic airframe/engine combination could do and Airbus realized based on Vmu and RTO tests there was more in there but then you need to open up the fuel side for it to make sense, otherwise you are running into fuel limitation. Include the -1000 fuel configuration and a 280t WV might suddenly makes sense in addition to 138,000l and 275t. I am speculating but it could be what is behind it all.

      There are a number of airlines that need to cross the Pacific between popular cities and these are many times at ULH distances, a WV that extracts the max of the -900 airframe and engine combination is probably worth the effort.

  3. How long would it take tho put this plane together? Why not use -100 wings and engines and carry more passengers to jfk?

    • SQ is starting to take deliveries of A350-900 next spring. As the -900LR is only a 1.8% TOW increase over what Airbus has already certified it can be done fast, it is doubtful if any changes will be needed. The -1000 wing tank concept for more fuel will be finished for production this year, first -1000 prototype is going to FAL Q1 2016.

      Compare that to a totally changed design as you propose, the original -900R concept, the -900 fuselage would have to be adapted to the -1000 landing gear which takes another frame of space etc, this would not be available before 2019 or so. Then the whole package would have to run a rather extensive certification program, you have stronger engines on a shorter body > can change stall and risk for spin behavior etc with engine out situations.

  4. Hi Bjorn

    This is not really related to the specific version of the A350, but the order itself. SQ first had 70 on order, and not to long ago they released seven aircraft back to manufacturer (??) taking the order to 63.
    What is this practice and is it done often? what are the benefits for both parties?

    And now I see that as part of this deal they are exercising four options and taking the number up to 67. It all seems pretty confusing…

    • We don’t know but it might have been a practical way if SQ wanted very different conditions around this contract to the contract that was signed way back in 2007.

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