777-300ER Range Improvement

[zvezda]

Boeing just released new Z-charts for the 777-200LR, 777F, and 777-300ER. The range improvement is (under conditions relevant to operating 777-300ERs SFO/LAX-SIN) 250nm. The improvement seems to be due to a reduction in SFC for the GE90s, so SQ's existing fleet can probably benefit when the engines are changed. This range increase may or may not suffice to make SFO/LAX-SIN nonstop commercially feasible.

[B727]

This range increase may or may not suffice to make SFO/LAX-SIN nonstop commercially feasible.

That would be great, particularly if they want to keep the nonstop USA flights all-business class only. It seems a shame for the A345 with its four engines to be flying that route. Most all-business flights I know are operated with twin-jets (granted none of them fly routes as long as the SIN-USA nonstops )

I was looking at those 773s taking off at Changi the other day and thought, these are some sleek planes! Aesthetically speaking, they are indeed comparable to the 343/345/346 which with the four engines are better off carrying a full payload and to their maximum range.

[zvezda]

That would be great, particularly if they want to keep the nonstop USA flights all-business class only.

I think the 777-300ER is too large for all-business class. I would expect SQ to want to keep the current cabin configuration.

[zvezda]

I note that range of the 777-300ER for SFO/LAX-SIN nonstop is limited by fuel volume, not by MTOW.

I've been working the numbers and I've convinced myself that the improved range still doesn't suffice for LAX-SIN. The payload restrictions would be too severe for economic viability and there would be too many diversions (typically to TPE) for unplanned fuel stops. SFO-SIN nonstop might or might not work.

Since increasing MTOW won't help and increasing fuel capacity is unlikely, the options to squeeze out more range are:
- reduce weight (Boeing are known to be working on this, with a possible reduction of 7-10 tonnes)
- further reduce fuel consumption of the GE90-110/115B (GE are known to be working on this), or
- improve aerodynamic efficiency (this seems less likely).

[9V-SIA]

Is it so easy to reduce weight?

Wish Airbus will do it for the A345!

[zvezda]

Is it so easy to reduce weight?

No, it is not easy to reduce weight. Most of the weight reduction Boeing are contemplating for the 777 is in the cabin.

Wish Airbus will do it for the A345!

Extremely unlikely, as the A340 is already not selling and the A350 will perform the same missions at much lower operating cost.