Section 6.3: Wooden Airframe Structures

Vocabulary terms covering the materials, components, and construction methods of wooden aircraft airframes as described in the lecture notes.

Truss-type fuselage construction

A method of creating a framework of wooden longerons and struts arranged in a triangular pattern to provide strength and rigidity at a low weight.

Longerons

Wooden beams that form part of the truss framework in a fuselage, running longitudinally to provide primary structural support.

Bulkheads

Structural components added to the framework to provide rigidity and help define the aerodynamic profile of the fuselage.

Stringers

Longitudinal members that provide additional rigidity and help shape the aerodynamic profile of the aircraft structure.

SITKA spruce

A lightweight, strong wood commonly used for aircraft spars due to its excellent strength-to-weight ratio.

Spars

The principal structural members of a wing that run spanwise (parallel to the lateral axis) and support distributed loads and concentrated weights like the fuselage and landing gear.

Compression struts

Structural members, often made of steel or heavy-wall aluminium alloy tubing, used to separate the wing spars within the truss structure.

Drag wires

High-strength solid steel wires that extend from the front spar inboard to the rear spar outboard to oppose forces that tend to pull the wing backwards.

Anti-drag wires

High-strength steel wires attached to the rear spar inboard and the front spar outboard that oppose forces tending to move the wing tip forward.

Wing butt ribs

Ribs located at the inboard edge of the wing where it attaches to the fuselage, sometimes called bulkhead or compression ribs.

Compression rib

A rib designed to receive compression loads that tend to force the wing spars together.

Box beam spar

A specific wooden spar configuration built as a box structure to accept both torsional and bending loads during flight.

Wing Ribs

Structural crosspieces extending from the leading edge to the trailing edge that give the wing its cambered shape and transmit air loads to the spars.

Webs

The internal framework of the ribs that provides shear strength and stiffness to the structure.

Rib cap

Also called a cap strip, this component is fastened around the perimeter of the rib to strengthen it and provide an attaching surface for the wing covering.