Aircraft Materials: Wooden and Fabric Structures Practice Flashcards

Comprehensive vocabulary flashcards covering aircraft wooden structures, fabric coverings, construction methods, wood types, glues, and maintenance standards as per CASA B1-06d.

Truss

A form of construction in which several members are joined to form a rigid structure.

Pratt Truss

A fuselage construction type where wooden longerons are separated by struts that carry only compressive loads and stays that carry only tension loads.

Warren Truss

A structure using longerons separated by diagonal members that can carry both compressive and tensile loads.

Longerons

The primary longitudinal structural load-bearing components in a truss fuselage.

Compression Struts

Members placed between the front and rear spars to prevent them from being pulled together and crushing the ribs.

Drag Wires

Wires that oppose loads tending to push the wing rearwards, opposite the direction of flight.

Anti-Drag Wires

Wires that support the wing in the opposite direction of the drag wires to provide strength and rigidity.

Monocoque Construction

A structural system, also called stressed skin, that supports loads through the external skin and lacks a load-carrying internal frame.

Sitka Spruce

The reference wood for all aircraft structures due to its uniformity, strength, and excellent shock-resistance qualities.

Laminated Wood

Two or more layers of solid wood bonded together with the grain of each layer running parallel to the others.

Plywood

Veneers bonded together where grain directions normally alternate at $90^{\circ}$ for rigidity.

Standard Wood Moisture Content

The normally acceptable moisture level for aircraft wood, which is $15\% \pm 2\%$.

Maximum Acceptable Grain Slope

The maximum allowabe rise in grain over length for aviation-grade wood, defined as $1:15$.

Pot Life

The usable life of glue from the time it is mixed until the time it must be discarded.

Open-Assembly Time

The allowable time between applying the glue and assembling the joint.

Closed-Assembly Time

The allowable length of time between assembling the joint and applying clamping pressure.

Casein Glue

An obsolete powdered glue made from milk that deteriorates with moisture and is often incompatible with modern glues.

Resorcinol Glue

A two-part synthetic resin consisting of resin and hardener that is the most water-resistant of used glues.

Dry Rot

A contagious defect occurring at the base of living trees, characterized by softness, discoloration, and a mushroom-like odor.

Scarf Repair

A repair for solid or rectangular wood spars that requires a specific taper and matching bevel cuts for strength.

Warp

Fabric threads that run the length of the material as it comes off the roll, designated as $0^{\circ}$.

Fill (Woof or Weft)

Fabric threads that run perpendicular at $90^{\circ}$ to the warp fibers.

Bias

The fiber orientation running at a $45^{\circ}$ angle to the warp threads, allowing manipulation for contoured shapes.

Greige

The unshrunk condition of polyester fabric as it is removed from the loom, prior to bleaching or dyeing.

Grommets

Doughnut-shaped rings of aluminum, plastic, or brass used to create reinforced drain and ventilation holes in fabric.

Cellulose Nitrate Dope

The oldest fabric finish with superior encapsulation characteristics but the drawback of being highly flammable.

Butyrate Dope

Cellulose acetate butyrate (CAB) which is less easily ignited than nitrate dope and has better tautening characteristics.

Aluminum Paste

An opaque coating of aluminum flakes applied to block ultraviolet (UV) rays from penetrating the fabric and dope.

70% Breaking Strength Rule

Fabric is considered unairworthy when it deteriorates to a breaking strength less than $70\%$ of the strength of the new fabric required.