Originally Posted by
FlightPathOBN
Notice the 787, no winglets there....they use a raked wingtip design, which I believe is what the 777x and A350 will all have..
It seems to be an general trend to increase the span of new airliners.
It seems the older designs have usually rather (too) short span. This is where the winglets shine.
When designed from the get go with the optimum span winglets probably won't bring enough benefit to compensate for the additional wave drag/form drag + the added structural weight + costs.
Maybe due to rising fuel prices the additional costs / restrictions resulting from airport fees / limitations with increased span seem to take a bit of a back seat compared to raw efficiency nowadays. Last but not least improvements in structural design/computation allow for longer, higher aspect ratio wings without excessive structural weight penalty.
Looking at further rising fuel prices in future I would not be surprised to see even longer span airliners potentially with slightly reduced cruise speeds.