![737-700f](https://upload.wikimedia.org/wikipedia/commons/1/10/737-700f.gif)
The fuselage (; from the
French ''fuselé'' "spindle-shaped") is an
aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...
's main body section. It holds
crew
A crew is a body or a class of people who work at a common activity, generally in a structured or hierarchical organization. A location in which a crew works is called a crewyard or a workyard. The word has nautical resonances: the tasks involve ...
, passengers, or
cargo
Cargo consists of bulk goods conveyed by water, air, or land. In economics, freight is cargo that is transported at a freight rate for commercial gain. ''Cargo'' was originally a shipload but now covers all types of freight, including trans ...
. In single-engine aircraft, it will usually contain an
engine
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gen ...
as well, although in some
amphibious aircraft
An amphibious aircraft or amphibian is an aircraft (typically fixed-wing) that can take off and land on both solid ground and water, though amphibious helicopters do exist as well. Fixed-wing amphibious aircraft are seaplanes ( flying boats ...
the single engine is mounted on a
pylon attached to the fuselage, which in turn is used as a floating
hull. The fuselage also serves to position the
control
Control may refer to:
Basic meanings Economics and business
* Control (management), an element of management
* Control, an element of management accounting
* Comptroller (or controller), a senior financial officer in an organization
* Controllin ...
and
stabilization surfaces in specific relationships to
lifting surfaces, which is required for aircraft stability and maneuverability.
Types of structures
Truss structure
This type of structure is still in use in many lightweight aircraft using
welded
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
tube trusses.
A box truss fuselage structure can also be built out of wood—often covered with plywood. 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.
Geodesic construction
![Vickers Wellington Mark X, HE239 'NA-Y', of No](https://upload.wikimedia.org/wikipedia/commons/9/94/Vickers_Wellington_Mark_X%2C_HE239_%27NA-Y%27%2C_of_No._428_Squadron_RCAF_%28April_1943%29.png)
Geodesic structural elements were used by
Barnes Wallis
Sir Barnes Neville Wallis (26 September 1887 – 30 October 1979) was an English engineer and inventor. He is best known for inventing the bouncing bomb used by the Royal Air Force in Operation Chastise (the "Dambusters" raid) to attack ...
for British
Vickers
Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...
between the wars and into
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
to form the whole of the fuselage, including its aerodynamic shape. In this type of construction multiple flat strip stringers are wound about the formers in opposite spiral directions, forming a basket-like appearance. This proved to be light, strong, and rigid and had the advantage of being made almost entirely of wood. A similar construction using aluminum alloy was used in the
Vickers Warwick
The Vickers Warwick was a multi-purpose twin-engined British aircraft developed and operated during the Second World War. In line with the naming convention followed by other RAF heavy bombers of the era, it was named after a British city or ...
with less material than would be required for other structural types. The geodesic structure is also redundant and so can survive localized damage without catastrophic failure. A fabric covering over the structure completed the aerodynamic shell (see the
Vickers Wellington
The Vickers Wellington was a British twin-engined, long-range medium bomber. It was designed during the mid-1930s at Brooklands in Weybridge, Surrey. Led by Vickers-Armstrongs' chief designer Rex Pierson; a key feature of the aircraft is its g ...
for an example of a large warplane which uses this process). The logical evolution of this is the creation of fuselages using molded plywood, in which multiple sheets are laid with the grain in differing directions to give the monocoque type below.
Monocoque shell
![vans](https://upload.wikimedia.org/wikipedia/commons/7/7e/Vans.rv-7.g-kels.arp.jpg)
In this method, the exterior surface of the fuselage is also the primary structure. A typical early form of this (see the
Lockheed Vega
The Lockheed Vega is an American five- to seven-seat high-wing monoplane airliner built by the Lockheed Corporation starting in 1927. It became famous for its use by a number of record-breaking pilots who were attracted to the rugged and very l ...
) was built using molded
plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...
, where the layers of plywood are formed over a "plug" or within a
mold
A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...
. A later form of this structure uses
fiberglass
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...
cloth impregnated with polyester or epoxy resin as the skin, instead of plywood. 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
The Rutan VariEze is a composite, canard aircraft designed by Burt Rutan. It is a high-performance homebuilt aircraft, hundreds of which have been constructed. The design later evolved into the Long-EZ and other, larger cabin canard aircraft ...
). An example of a larger molded plywood aircraft is the
de Havilland Mosquito
The de Havilland DH.98 Mosquito is a British twin-engined, shoulder-winged, multirole combat aircraft, introduced during the Second World War. Unusual in that its frame was constructed mostly of wood, it was nicknamed the "Wooden Wonder", or ...
fighter/light bomber of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
.
No plywood-skin fuselage is truly
monocoque
Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell".
First used for boats, ...
, since stiffening elements are incorporated into the structure to carry concentrated loads that would otherwise buckle the thin skin.
The use of molded fiberglass using negative ("female") molds (which give a nearly finished product) is prevalent in the series production of many modern
sailplane
A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplan ...
s. The use of molded composites for fuselage structures is being extended to large passenger aircraft such as the
Boeing 787
The Boeing 787 Dreamliner is an American wide-body jet airliner developed and manufactured by Boeing Commercial Airplanes.
After dropping its unconventional Sonic Cruiser project, Boeing announced the conventional 7E7 on January 29, 2003, ...
''Dreamliner'' (using pressure-molding on female molds).
Semi-monocoque
![Fuselage-747](https://upload.wikimedia.org/wikipedia/commons/c/c2/Fuselage-747.jpg)
This is the preferred method of constructing an all-
aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...
fuselage. First, a series of
frames in the shape of the fuselage cross sections are held in position on a
rigid fixture. These frames are then joined with lightweight longitudinal elements called
stringers. These are in turn covered with a skin of sheet aluminum, attached by
rivet
A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite to the head is called the ''tail''. On installation, the rivet is placed in a punched ...
ing 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
fastener
A fastener (US English) or fastening (UK English) is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or disman ...
s 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
The Douglas DC-2 is a 14-passenger, twin-engined airliner that was produced by the American company Douglas Aircraft Company starting in 1934. It competed with the Boeing 247. In 1935, Douglas produced a larger version called the DC-3, which bec ...
and
DC-3
The Douglas DC-3 is a propeller-driven airliner
manufactured by Douglas Aircraft Company, which had a lasting effect on the airline industry in the 1930s to 1940s and World War II.
It was developed as a larger, improved 14-bed sleeper version ...
civil aircraft and the Boeing
B-17 Flying Fortress
The Boeing B-17 Flying Fortress is a four-engined heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC). Relatively fast and high-flying for a bomber of its era, the B-17 was used primarily in the European Theater ...
. 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
{{Wiktionary
Pressurization or pressurisation is the application of pressure in a given situation or environment.
Industrial
Industrial equipment is often maintained at pressures above or below atmospheric.
Atmospheric
This is the process by ...
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
![Fisher FP-202 Koala D-MKOA fuselage](https://upload.wikimedia.org/wikipedia/commons/0/08/Fisher_FP-202_Koala_D-MKOA_fuselage.jpg)
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
A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft.
The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...
windshields on the
Airbus A320
The Airbus A320 family is a series of Narrow-body aircraft, narrow-body airliners developed and produced by Airbus.
The A320 was launched in March 1984, Maiden flight, first flew on 22 February 1987, and was introduced in April 1988 by Air F ...
must withstand
bird strike
A bird strike—sometimes called birdstrike, bird ingestion (for an engine), bird hit, or bird aircraft strike hazard (BASH)—is a collision between an airborne animal (usually a bird or bat) and a moving vehicle, usually an aircraft. The term ...
s up to and are made of
chemically strengthened glass
Chemically strengthened glass is a type of glass that has increased strength as a result of a post-production chemical process. When broken, it still shatters in long pointed splinters similar to float glass. For this reason, it is not considered a ...
. 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
In aviation and aerospace, foreign object debris (FOD), is any particle or substance, alien to an aircraft or system, which could potentially cause damage.
External FOD hazards include bird strikes, hail, ice, sandstorms, ash-clouds or obje ...
and
abrasion, with often a
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, th ...
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
A coating is a covering that is applied to the surface of an object, usually referred to as the Substrate (materials science), substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquid ...
of
indium tin oxide Indium tin oxide (ITO) is a ternary composition of indium, tin and oxygen in varying proportions. Depending on the oxygen content, it can be described as either a ceramic or an alloy. Indium tin oxide is typically encountered as an oxygen-saturated ...
sitting between plies, electrically conductive and thus transmitting heat.
Curved
In mathematics, a curve (also called a curved line in older texts) is an object similar to a line, but that does not have to be straight.
Intuitively, a curve may be thought of as the trace left by a moving point. This is the definition that a ...
glass improves
aerodynamics
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
but
sight
Visual perception is the ability to interpret the surrounding Biophysical environment, environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the ...
criteria also needs larger panes. A cockpit windshield is composed of 4–6 panels, 35 kg (77 lb) each on an
Airbus A320
The Airbus A320 family is a series of Narrow-body aircraft, narrow-body airliners developed and produced by Airbus.
The A320 was launched in March 1984, Maiden flight, first flew on 22 February 1987, and was introduced in April 1988 by Air F ...
. In its lifetime, an average aircraft goes through three or four
windshield
The windshield (North American English) or windscreen (Commonwealth English) of an aircraft, car, bus, motorbike, truck, train, boat or streetcar is the front window, which provides visibility while protecting occupants from the elements. Mo ...
s, and the market is shared evenly between
OEM
An original equipment manufacturer (OEM) is generally perceived as a company that produces non-aftermarket parts and equipment that may be marketed by another manufacturer. It is a common industry term recognized and used by many professional or ...
and higher margins
aftermarket.
[
Cabin windows, made from much lighter than glass stretched ]acrylic glass
Poly(methyl methacrylate) (PMMA) belongs to a group of materials called engineering plastics. It is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite, ...
, consists of multiple panes: an outer one built to support four times the maximum cabin pressure, an inner one for redundancy and a scratch pane near the passenger. Acrylic is susceptible to crazing
Crazing is the phenomenon that produces a network of fine cracks on the surface of a material, for example in a glaze layer. Crazing frequently precedes fracture in some glassy thermoplastic polymers. As it only takes place under tensile stress, ...
: a network of fine cracks appears but can be polished to restore optical transparency
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable light scattering by particles, scattering of light. On a macroscopic scale ...
, removal and polishing typically undergo every 2–3 years for uncoated windows.
Wing integration
"Flying wing
A flying wing is a tailless fixed-wing aircraft that has no definite fuselage, with its crew, payload, fuel, and equipment housed inside the main wing structure. A flying wing may have various small protuberances such as pods, nacelles, blis ...
" 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
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding th ...
's experimental lifting body
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage wi ...
designs and the Vought
Vought was the name of several related American aerospace firms. These have included, in the past, Lewis and Vought Corporation, Chance Vought, Vought-Sikorsky, LTV Aerospace (part of Ling-Temco-Vought), Vought Aircraft Companies, and Vought Ai ...
XF5U-1 Flying Flapjack.
A blended wing body
A blended wing body (BWB), also known as blended body or hybrid wing body (HWB), is a fixed-wing aircraft having no clear dividing line between the wings and the main body of the craft. The aircraft has distinct wing and body structures, which a ...
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
The Boeing X-48 is an American experimental unmanned aerial vehicle (UAV) built to investigate the characteristics of blended wing body (BWB) aircraft. Boeing designed the X-48 and two examples were built by Cranfield Aerospace in the UK. Bo ...
. One of the earliest aircraft using this design approach is Burnelli CBY-3
The Burnelli CBY-3 Loadmaster is an unconventional transport aircraft that was designed by American engineer Vincent Burnelli and built in Canada in 1944 by Canadian Car and Foundry.
Design and development
The CBY-3 " lifting fuselage" was an ev ...
, 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
The Airbus A340 is a long-range, wide-body passenger airliner that was developed and produced by Airbus.
In the mid-1970s, Airbus conceived several derivatives of the A300, its first airliner, and developed the A340 quadjet in parallel with ...
, showing the rear bulkhead as well as a doorway opening
File:Boeing 747 Le Bourget FRA 002.jpg, Rough Boeing 747
The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2022.
After introducing the 707 in October 1958, Pan Am wanted a jet times its size, t ...
interior airframe
The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system.
Airframe design is a field of aerospa ...
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
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
, as in this Christen Eagle
File:Glider fuselage schematic.JPG, Glider
Glider may refer to:
Aircraft and transport Aircraft
* Glider (aircraft), heavier-than-air aircraft primarily intended for unpowered flight
** Glider (sailplane), a rigid-winged glider aircraft with an undercarriage, used in the sport of glidin ...
fuselage schematic
See also
* Aeronautics
Aeronautics is the science or art involved with the study, design, and manufacturing of air flight–capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identifies ...
* Airframe
The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system.
Airframe design is a field of aerospa ...
* Empennage
The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...
* Nose art
Nose art is a decorative painting or design on the fuselage of an aircraft, usually on the front fuselage.
While begun for practical reasons of identifying friendly units, the practice evolved to express the individuality often constrained by ...
* Aviation accidents and incidents
An aviation accident is defined by the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft, which takes place from the time any person boards the aircraft with the ''intention of f ...
References
External links
NASA page on fuselage
Institute of Aircraft Design and Lightweight Structures (IFL)
*
*
{{Aircraft components
Aircraft components