Fuselage - WikiHQ

thumb|Fuselage of a [[Boeing 737 shown in brown]]

The fuselage (; from the French fuselé "spindle-shaped") is an aircraft's main body section.

| image1 = Monocoque fuselage design.png

| caption1 = Monocoque construction uses stressed skin to support almost all loads much like an aluminum beverage can.

| image2 = Semimonocoque fuselage design.png

| caption2 = Semi-monocoque construction, partial or one-half, uses a substructure to which the airplane's skin is attached.

thumb|upright|Sectioned fuselage of a [[Boeing 747 showing formers, stringers and skin all made of aluminium]]

This is the preferred method of constructing an all-aluminum fuselage. First, a series of formers in the shape of the fuselage cross sections are held in position on a rigid fixture. These formers are then joined with lightweight longitudinal elements called stringers. These are in turn covered with a skin of sheet aluminum, attached by riveting or by bonding with special adhesives. The fixture is then disassembled and removed from the completed fuselage shell, which is then fitted out with wiring, controls, and interior equipment such as seats and luggage bins. Most modern large aircraft are built using this technique, but use several large sections constructed in this fashion which are then joined with fasteners to form the complete fuselage. As the accuracy of the final product is determined largely by the costly fixture, this form is suitable for series production, where many identical aircraft are to be produced. Early examples of this type include the Douglas Aircraft DC-2 and DC-3 civil aircraft and the Boeing B-17 Flying Fortress. Most metal light aircraft are constructed using this process.

Both monocoque and semi-monocoque are referred to as "stressed skin" structures as all or a portion of the external load (i.e. from wings and empennage, and from discrete masses such as the engine) is taken by the surface covering. In addition, all the load from internal pressurization is carried (as skin tension) by the external skin.

The proportioning of loads between the components is a design choice dictated largely by the dimensions, strength, and elasticity of the components available for construction and whether or not a design is intended to be "self jigging", not requiring a complete fixture for alignment.

Materials

thumb|upright|Inside view of the wooden, fabric-covered fuselage of a [[Fisher FP-202 Koala|Fisher FP-202.]]

Early aircraft were constructed of wood frames covered in fabric. As monoplanes became popular, metal frames improved the strength, which eventually led to all-metal-structure aircraft, with metal covering for all its exterior surfaces - this was first pioneered in the second half of 1915. Some modern aircraft are constructed with composite materials for major control surfaces, wings, or the entire fuselage such as the Boeing 787. On the 787, it makes possible higher pressurization levels and larger windows for passenger comfort as well as lower weight to reduce operating costs. The Boeing 787 weighs less than if it were an all-aluminum assembly.

Windows

Cockpit windshields on the Airbus A320 must withstand bird strikes up to and are made of chemically strengthened glass. They are usually composed of three layers or plies, of glass or plastic : the inner two are 8 mm (0.3 in.) thick each and are structural, while the outer ply, about 3 mm thick, is a barrier against foreign object damage and abrasion, with often a hydrophobic coating. It must prevent fogging inside the cabin and de-ice from . This was previously done with thin wires similar to a rear car window but is now accomplished with a transparent, nanometers-thick coating of indium tin oxide sitting between plies, electrically conductive and thus transmitting heat. Curved glass improves aerodynamics but sight criteria also needs larger panes. A cockpit windshield is composed of 4–6 panels, 35 kg (77 lb) each on an Airbus A320. In its lifetime, an average aircraft goes through three or four windshields, and the market is shared evenly between OEM and higher margins aftermarket.

Wing integration

"Flying wing" aircraft, such as the Northrop YB-49 Flying Wing and the Northrop B-2 Spirit bomber have no separate fuselage; instead what would be the fuselage is a thickened portion of the wing structure.

Conversely, there have been a small number of aircraft designs which have no separate wing, but use the fuselage to generate lift. Examples include National Aeronautics and Space Administration's experimental lifting body designs and the Vought XF5U-1 Flying Flapjack.

A blended wing body can be considered a mixture of the above. It carries the useful load in a fuselage producing lift. A modern example is Boeing X-48. One of the earliest aircraft using this design approach is Burnelli CBY-3, which fuselage was airfoil shaped to produce lift.

Gallery

File:Airbus A340 Intérieur Fuselage Arrière.JPG|Interior rear-end of the main passenger level on an Airbus A340, showing the rear bulkhead as well as a doorway opening

File:Boeing 747 Le Bourget FRA 002.jpg|Rough Boeing 747 interior airframe

File:CubCrafters Fuselage.jpg|Fuselage of a CubCrafters Carbon Cub

File:christen.eagle.2.g-ccyo.arp.jpg|The fuselage can be short, and seemingly unaerodynamic, as in this Christen Eagle

File:Glider fuselage schematic.JPG|Glider fuselage schematic

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References

External links

NASA page on fuselage