Fuselage
Simple box structures may be rounded by the addition of supported lightweight stringers, allowing the fabric covering to form a more aerodynamic shape, or one more pleasing to the eye.
In this type of construction multiple flat strip stringers are wound about the formers in opposite spiral directions, forming a basket-like appearance.
The logical evolution of this is the creation of fuselages using molded plywood, in which several sheets are laid with the grain in differing directions to give the monocoque type below.
A simple form of this used in some amateur-built aircraft uses rigid expanded foam plastic as the core, with a fiberglass covering, eliminating the necessity of fabricating molds, but requiring more effort in finishing (see the Rutan VariEze).
No plywood-skin fuselage is truly monocoque, since stiffening elements are incorporated into the structure to carry concentrated loads that would otherwise buckle the thin skin.
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.
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.
On the 787, it makes possible higher pressurization levels and larger windows for passenger comfort as well as lower weight to reduce operating costs.
[citation needed] Cockpit windshields on the Airbus A320 must withstand bird strikes up to 350 kn (650 km/h) and are made of chemically strengthened glass.
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.
Examples include National Aeronautics and Space Administration's experimental lifting body designs and the Vought XF5U-1 Flying Flapjack.
