The fuselage is the central body of the airplane and the largest element of it. The fuselage extends from the nose to the tail of the machine. The fuselage is divided into the front fuselage, centre fuselage and rear fuselage.
Fuselages of all airplanes are similar in general design, location and outline. All the fuselages are round structures and have streamlined shape to reduce the drag. They vary principally in size and in the arrangement of the compartments.
The fuselage is a rigid framework built of tubular steel and metal rings. The framework is covered with a thin-walled skin. The framework consists of longitudinal members (stringers) and transversal members (formers and bulkheads). Stringers serve to stiffen the skin. Formers and bulkheads are used to maintain the circular cross section of the fuselage. These longitudinal and transversal members will make the contour of the fuselage. The fuselages of modem aircraft are of all-metal construction.
There are two main types of the fuselage construction monocoque design and semimonocoque. Monocoque is the structure made in the form of a shell . The French word «monocoque» means «single shell». It is a hollow construction. In the monocoque design the skin provides its own structural strength, eliminating the need for internal bracings. The reinforced monocoque design uses complete metal formers, normally of welded tubular steel, covered with a metal skin.
In semimonocoque type of the construction the longitudinal members are held apart by bulkheads and formers.
Monocoque – A shell-like fuselage design in which the stressed outer skin is used to support the majority of imposed stresses. Monocoque fuselage design may include bulkheads but not stringers: Skin, Former, Bulkhead.
Semi-Monocoque – A fuselage design that includes a substructure of bulkheads and/or formers, along with stringers, to support flight loads and stresses imposed on the fuselage.
The fuselage contains the cockpit or flight deck, passenger cabins, baggage compartments and equipment. Pressurized cabins are used in modern aircraft. The cabin windows, canopy, hatches and doors are the most vital parts of the pressurized cabin.