In an

aircraft An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

, ribs are forming elements of the

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 aeros ...

structure of a

wing A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-d ...

, especially in traditional construction. By analogy with the anatomical definition of "

rib In vertebrate anatomy, ribs () are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the thoracic cavity, enabling the lungs to expand and thus facilitate breathing by expanding the ...

", the ribs attach to the main spar, and by being repeated at frequent intervals, form a skeletal shape for the wing. Usually ribs incorporate the

airfoil An airfoil (American English) or aerofoil (British English) is a streamlined body that is capable of generating significantly more Lift (force), lift than Drag (physics), drag. Wings, sails and propeller blades are examples of airfoils. Foil (fl ...

shape of the wing, and the skin adopts this shape when stretched over the ribs.

Type of ribs

There are several types of ribs. Form-ribs, plate-type ribs, truss ribs, closed-ribs, forged ribs and milled ribs, where form-ribs are used for light to medium loading and milled ribs offer the greatest strength. * Form-ribs are made from a sheet of metal bent into shape, such as a U-profile. This profile is placed on the skin, just like a

stringer Stringer may refer to: Structural elements * Stringer (aircraft), or longeron, a strip of wood or metal to which the skin of an aircraft is fastened * Stringer (slag), an inclusion, possibly leading to a defect, in cast metal * Stringer (stairs), ...

, but then in the other direction. * Plate-type ribs consist of sheet-metal, which has upturned edges and (often has) weight-saving holes cut into it. * Truss ribs are built up out of profiles that are joined together. These joints require great attention during design and manufacture. The ribs may be light or heavy in design which make them suitable for a wide range of loads. * Closed-ribs are constructed from profiles and sheet metal and are suitable for closing off sections of the wing (e.g.: the fuel tank). Here too, particular care must be taken with the joints and this type of rib is also suitable for application in a variety of loading conditions. *

Forged Forging is a manufacturing process involving the shaping of metal using localized compression (physics), compressive forces. The blows are delivered with a hammer (often a power hammer) or a die (manufacturing), die. Forging is often classif ...

ribs are manufactured using heavy press-machinery. The result is fairly rough; for more refined parts, high-pressure presses are required, which are very expensive. Forged pieces (usually) have to undergo further treatment (for smoother edges and holes). Forged ribs are used for sections where very high loads apply - near the undercarriage for example. * Milled ribs are solid structures. They are manufactured by milling away excess material from a solid block of metal (usually using computer-controlled milling machines). The shape of these ribs is always accurately defined. Such ribs are used under similar conditions as those for forged ribs. Ribs are made out of wood, metal, plastic, composites, foam. The wings of

kite A kite is a tethered heavier than air flight, heavier-than-air craft with wing surfaces that react against the air to create Lift (force), lift and Drag (physics), drag forces. A kite consists of wings, tethers and anchors. Kites often have ...

hang glider Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised, fixed-wing heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame covered ...

paraglider Paragliding is the recreational and competitive adventure sport of flying paragliders: lightweight, free-flying, foot-launched Glider (aircraft), glider aircraft with no rigid primary structure. The pilot sits in a :wikt:harness, harness or in ...

s, powered kites,

powered hang glider A foot-launched powered hang glider (FLPHG), also called powered harness, nanolight, or hangmotor, is a powered hang glider harness with a motor and propeller often in pusher configuration, although some can be found in tractor configuration. ...

s, ultralights, windmills Windmill with ribs in its wings
/ref> are aircraft that have versions that use ribs to form the wing shape. For full size and flying model aircraft wing structures that are usually made of wood, ribs can either be in one piece (forming the airfoil at that rib's "station" in the wing), or be in a three-piece format, with the ''rib web'' being the part that the one-piece rib consisted of, with ''capstrips'' for the upper and lower edging of the rib, running from the leading edge to the trailing edge, being the other two component parts.

References

{{DEFAULTSORT:Rib (Aircraft) Aircraft wing components

Type of ribs

See also

References