Originally Posted by flyclub
The Japanese have a Special Range (SR) derivative which is more capable weight-wise and has a high density seating (think charter layout) for busy Japanese Domestic routes. The only market in the world to offer them, I believe. However you are correct, I believe they are wing tip-less.
However, the 747-400F (Freight) has the wing tip, however no extended upper deck instead looks very reminiscent of the early -100 having only a few windows on the upper deck.
The hump also contributes to the 747-400 being one of the fastest Long Haul aircraft - something about a suction effect directly behind the hump on the roof of the aicraft.....
To take this a little further:
- The wingtips or wing fences on modern aircraft offer a few percent of fuel efficiency gains at cruising speed, but they also add to the weight that must be carried to cruising altitude. Therefore, for short hops the aircraft is more efficient without wingtips or wing fences.
- The "hump" allows a slightly higher cruising speed because the aircraft conforms more closely to the
Area rule which states that the cross-sectional area of a high speed aircraft should change as smoothly as possible, which is why many fighters have a "wasp waist" to compensate for the area of the wings.