As can be clearly seen in the accompanying photos of just such an aircraft, the most prominent feature of the wings are the enormous engines hanging from each of them. Those engines weigh in at roughly 9,000 pounds each - nearly 12,000 pounds each if we factor in the steel struts that support them (according to pentagonresearch.com and the ASCE). Some researchers have already pointed out that the aircraft's wings have to be quite strong to support those massive engines. That much seems rather obvious. Of far more significance, I would think, is that those engines are what propels the plane. In other words, in order for the plane to actually lift off the ground and fly, the engines, and hence the wings, have to literally drag that fully-loaded, 127-ton aircraft into the air and then pull it along to its destination.
It seems to me then that if a 757's wings were as flimsily attached to the fuselage as many researchers claim, we would regularly be treated to rather comical scenes of wingless jets sitting on runways while the wings themselves took flight in wild, unpredictable ways. And that's not the kind of thing you see on the evening news that often.
Also clearly visible in these photos is the aircraft's main landing gear, which also happens to be attached not to the fuselage, but to the wings. That landing gear adds nearly two tons of weight to each wing. More importantly, the fact that the gear is attached to the wings means that when the plane is on the ground, it is the wings - described by more than a few 9-11 skeptics as consisting of little more than a thin aluminum skin - that have to support almost the entire weight of the aircraft (up to 255,000 pounds at take-off). And when the plane lands, needless to say, that landing gear provides the first point of contact with the ground. It also provides the primary means of braking the aircraft to a stop. It seems safe then to conclude that the wings can not only support the entire weight of the plane but can also simultaneously arrest its considerable forward momentum. Imagine the stress that is placed on that landing gear as a 200,000+ pound airplane skips down the runway at a relatively high rate of speed and it becomes quite clear that the landing gear, and the wings themselves, have to be very securely attached to the fuselage.
Indeed, the area of the plane with the greatest structural strength, by any logical analysis, would have to be the span between those two enormously heavy, and enormously powerful, engines. In other words, the wings are not some insignificant appendages that are tacked on with a few aviation rivets and a wad of bubblegum; they are an integral part of the aircraft.
In addition to the engines and the main landing gear, the wings are also home to the aircraft's fuel tanks, which carry a combined 11,240 gallons of fuel (at least according to the graphic reproduced here; fuel capacity is listed elsewhere as 11,489 gallons or 11,275 gallons), weighing some 75,000 pounds. Each wing holds nearly 15,000 pounds of fuel and another 45,000 pounds, more or less, is stored in tanks between the wings.
According to the American Society of Civil Engineers, each wing of a Boeing 757-200 weighs in at a whopping 44,000 pounds, including the engine and struts, the landing gear, a full load of fuel, and the weight of the wing structure itself (steel and other metals account for about 2/3 of that weight, or roughly fifteen tons, with the fuel accounting for the other seven tons). If we add together the weight of the two wings (88,000 pounds), the weight of the fuel stored between the wings (45,000 pounds), and the weight of the heavily reinforced cross-section of the fuselage between the two wings, we come up with a figure, I would guess, somewhere in the neighborhood of 150,000 pounds. Since a fully fueled Boeing 757-200 weighs in at roughly 200,000 pounds (127,000 pounds for the aircraft and 75,000 pounds for the fuel), a little rudimentary arithmetic reveals that fully 3/4 of the aircraft's weight is distributed in the cross-section between the wing tips. The bulk of the fuselage, which appears to be the most massive portion of the plane, in reality accounts for only about 25% of the aircraft's total weight.
