Кстати, вот товарищ на airliners.net приводит примитивный рассчет эффективности 380 и 747:
Let's have a partial review of aircraft design 101.
According to Airbus's website, the empty weight of the 388 is 276.8t (
http://www.airbus.com/product/a380_specifications.asp ). So, the empty weight per seat is 498.7 kg/seat. There were reports of the 388 empty weight as high as 282t. But for the sake of this discussion, I will use the more optimistic number.
According to Boeing's website, the empty weight of the 744er is 184.6t (page 22 in
http://www.boeing.com/assocproducts/aircompat/acaps/7474sec2.pdf ). So, the empty weight per seat is 443.8 kg/seat. Usually, when you stretch an aircraft, the empty weight decreases. But the 747 Adv will have heavier engines, so let's assume the empty weight per seat is 450 kg/seat. Then the 388 will still have an empty weight per seat nearly 11% higher than the 747 Adv.
Simple physics tells you the heavier the object is the more energy you will need to move it. The 388 can't defy the laws of nature.
That's why Boeing doesn't need to put a lot of composite to make the 747 Adv competitive against the 388. The 388 has the advantage of having more seats to help lower the unit cost. Whether this is enough to overcome the weight inefficiency, Airbus will tell you yes, but Boeing will tell you no. Who is telling the truth? I think most of the people here won't be able to tell. But what I just said about the empty weight is black and white.
Вкратце — A-380-800 -ый весит больше в рассчете на одного пассажира, чем B-747-400, хотя по-идее должно быть наоборот.