In 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 engine ...

, ribs are forming elements of the structure of a

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is e ...

, especially in traditional construction. By analogy with the anatomical definition of " rib", the ribs attach to the main

spar SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...

, and by being repeated at frequent intervals, form a skeletal shape for the wing. Usually ribs incorporate the airfoil 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 compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at which it ...

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 or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the fac ...

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

paraglider Paragliding is the recreational and competitive adventure sport of flying paragliders: lightweight, free-flying, foot-launched glider aircraft with no rigid primary structure. The pilot sits in a harness or lies supine in a cocoon-like ' ...

s, powered kites,

powered hang glider A foot-launched powered hang glider (FLPHG), also called powered harness, nanolight, or hangmotor, is a powered hang gliding, hang glider harness with a internal combustion engine, motor and propeller (aircraft), propeller in pusher configuratio ...

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