CASA B-07b Maintenance Practices - General Key Exam Points

Vocabulary flashcards covering workshop practices, precision tool usage, drilling geometry, grinding faults, and torque procedures.

Workmanship

The degree of skill with which a product is made or a job is done, including quality, attitude, duty of care to self, others, and equipment, and working to a standard.

Standard

An agreed way of doing something, which may be private, national, or international (ISO).

Shadow boards

Storage boards that show both where a tool belongs and whether it is missing.

Tolerance

Permitted variation in dimension, which may be shown as a \begin{matrix} + / - \text{ value} \begin{matrix} or as the total difference between upper and lower limits.

Allowance

The prescribed difference between the maximum material limits of mating cylindrical parts.

Prick punch

A punch used to transfer dimensions or locations to sheet metal, which must not be used to drive pins or rivets.

Centre punch

A punch that makes a deeper witness mark to help a drill start accurately.

Starter drift

A tool used to jar loose taper and parallel pins.

Pin punch

A punch used to drive already-loosened pins, dowels, and rivets out.

Safe edge

An edge of a file that has no teeth, protecting adjacent surfaces during filing.

Bastard file

A file grade used for fast material removal or roughing.

Aviation snips handle color codes

Yellow handles cut straight, green handles cut right, and red handles cut left.

Hacksaw tooth contact rule

A requirement that at least $3$ teeth must remain in contact with the workpiece during cutting.

Standard drill point angle

The standard twist drill point angle equal to $118^\text{ degrees}$.

Countersink

A process that removes material for a flush fastener head, suitable when the skin or sheet is thick enough.

Dimple

A process that forms or presses material for a flush fastener head, used when the skin is too thin to countersink.

Reamer

A tool that enlarges an existing undersized hole to improve accuracy, finish, and concentricity, without correcting position or direction.

Die nut

A tool used to restore or ease damaged external threads, rather than cut new threads.

Spark-resistant tools

Tools made of materials such as brass, bronze, Monel, copper-aluminium, copper-beryllium, and titanium, used where sparks from steel tools could ignite flammable substances.

Loading

A grinding fault where material clogs spaces between abrasive grains, typically caused by using the wrong wheel on soft or ductile material.

Glazing

A grinding fault where abrasive grains become blunt but the bond will not release them, caused by grinding hard material with too hard a bond.

Truing

The process of making a grinding wheel square and concentric.

Dressing

The process of cleaning the cutting face of a grinding wheel to expose fresh abrasive.

Preload

The tensile stress induced in a bolt or stud by the application of torque.

Progressive torquing

Torquing in stages to prevent uneven loading.

Pattern torquing

A specific tightening sequence used to prevent distortion or uneven loading.

Torque wrench unusable region

The first $1/4$ of a torque wrench scale, which must not be used for aviation work due to insufficient accuracy.

Torque extension formula

The formula $\text{Scale reading} = \frac{\text{Specified torque} \times L}{L + X}$, where $L$ is the wrench length and $X$ is the extension length.