## What is the function of the wing spar?

The spar carries flight loads and the weight of the wings while on the ground. Other structural and forming members such as ribs may be attached to the spar or spars, with stressed skin construction also sharing the loads where it is used. There may be more than one spar in a wing or none at all.

### What is an aircraft wing spar?

Spars. In a fixed-wing aircraft, the spar is often the main structural member of the wing, running spanwise at right angles (or thereabouts depending on wing sweep) to the fuselage. The spar carries flight loads and the weight of the wings while on the ground.

#### What are the three types of wing construction?

The fuselage of an aircraft can be constructed in basically three different ways: truss, monocoque and stressed skin. The truss is a steel tube box like the construction of a crane.

Can wing spars be supported externally?

Wing Structure. Often wings are of full cantilever design. This means they are built so that no external bracing is needed. They are supported internally by structural members assisted by the skin of the aircraft.

How do you calculate wing spar?

A general approximation was calculated by multiplying the area of each cross section by its “length” of 12 inches, and then summing these areas and multiplying by the density. This yielded an approximation of a “tapered” beam. A more accurate weight was obtained by integrating the areas over the length.

## What do wing ribs do?

Ribs are the structural crosspieces that combine with spars and stringers to make up the framework of the wing. They usually extend from the wing leading edge to the rear spar or to the trailing edge of the wing. The ribs give the wing its cambered shape and transmit the load from the skin and stringers to the spars.

### What are different types of wings?

There are four general wing types:

• Elliptical Wings. Elliptical wings are found on bats and most small forest and scrub-dwelling birds, such as robins and sparrows.
• High Speed Wings. Wings designed for speed are found on swallows, falcons, shore birds, and ducks.
• Long Soaring Wings.

#### What type of wing has no external bracing?

Cantilever wings built with no external bracing are also shown. Figure 1-22. Externally braced wings, also called semicantilever wings, have wires or struts to support the wing. Full cantilever wings have no external bracing and are supported internally.

How is wing bending calculated?

The expressions that are derived can be used for load on the wing to calculate bending moment. The first step is to start by integrating total load to determine shear force: V(x) = – ∫ qr(x) dx. The bending moment can then be calculated by integrating shear force: M(x) = ∫ V(x) dx.

What is wing bending relief?

Wing bending relief This is because the lift on the wings and the weight of the fuselage bend the wing tips upwards and the wing roots downwards; but the weight of the wings, including the weight of fuel in the wings, bend the wing tips downwards, providing relief to the bending effect on the wing.

## What is a wing spar?

The spar webs and caps are collectively referred to as the wing spar. The ribs are spaced equidistant from one-another (as far as is practical) and help to maintain the aerodynamic profile of the wing.

### What drives the vertical shear and bending moment in wings?

This introduction will concentrate on the vertical shear and bending moment as these loads drive the wing design. An example of the distributed lift load and resulting shear and bending moment diagrams arising from this loading is shown below. In both cases it is clear that the location of the highest shear and bending is the wing root.

#### What is a rear spar on a plane?

A rear spar is often required in order to attach the trailing edge flap and aileron surfaces to the main wing structure. If the surfaces have already been specified during the conceptual phase (before the structural design is started) then these surfaces will form a natural constraint and drive the placement of the rear spar.

What happened to the L-164 wing spars?

Soon after our assembly started, an NTSB report came out in 2006 about a U.S.-registered L-164 experiencing a wing spar failure in flight that did not result in an accident — the pilot made a successful precautionary landing. The report cited a sudden aileron flutter that started at 135 mph in calm air and subsided as the pilot reduced speed.