Aviation Maintenance Block 2 Study Guide

Flashcards covering aviation maintenance topics including hardware identification, corrosion types and treatments, blueprint reading, and nondestructive testing (NDT) testing based on the Block 2 study guide.

Orthographic projection

A type of drawing where one-view, two-view, and three-view versions reflect the most common representations.

Aircraft wing skin repair sketching

The first step of this procedure is to block in the views.

Nylon-type locknut

Hardware that obtains its locking feature through the use of an unthreaded nylon locking insert.

Working drawings

A classification of drawings divided into three classes: detail drawings, assembly drawings, and installation drawings.

AN310

The part number identifying a castle nut.

Advisory Circular 43.13-1B

The source where recommended torque values can be found if a specific value is not otherwise provided.

Zone numbers

Numbers on aircraft blueprints used to locate parts, sections, and views on large drawings.

Electrolyte

Of the four conditions required for corrosion to begin, this is the easiest to remove.

Anodic metals

In the Galvanic or Electro-Chemical Series, these are the metals that will give up electrons most easily.

Intergranular corrosion

A type of corrosion in structural aluminum alloy parts that cannot always be detected by surface indications; it is often caused by improper heat treatment.

MS20470AD4-5

A solid shank rivet part number where the "5" stands for a length of $5/16$ of an inch.

Microorganisms

A factor that having an accelerating effect on the rate of metal corrosion.

Double twist safety wiring

A method of hand safety wiring that should have $6$ to $8$ twists per inch.

Eddy current inspection

A nondestructive test used to detect cracks, pitting, and discontinuities at or below the surface.

NAS close tolerance steel bolt

Identified by an $X$ inside a triangle on the head of the bolt.

Magnetic Particle Inspection

A process used to detect flaws in alloys composed of ferrous materials such as iron or steel.

Plastic surface cleaning

A process involving flushing the surface with fresh water before cleaning with soap and water to prevent scratching.

Hidden line

A line used on a drawing to show an edge which is not visible.

Galvanic corrosion

Corrosion caused by dissimilar metals in contact.

Dimensions

The means of conveying specific measurements through the medium of drawings.

Cast iron symbol

The material symbol frequently used in drawings to represent all metals.

Nylon-type self-locking nut restrictions

This hardware must never be used if the bolt is subject to rotation and high heat.

Magnesium

Between 2024 aluminum alloy, stainless steel, and zinc, this is the most anodic material and the most corrosion prone metal used on aircraft.

Shop head

The common term for the end of a solid shank rivet that is upset by the application of a bucking bar.

Exfoliation

The lifting or flaking of metal at the surface due to delamination of grain boundaries caused by the pressure of corrosion residual product buildup.

Boric acid

A solution used to neutralize nickel-cadmium battery cases and surfaces affected by electrolyte.

Alodizing

A chemical treatment for aluminum alloys to improve paint-bonding qualities and increase corrosion resistance.

5052-H36

A metal designation where magnesium is the primary alloying agent.

Tolerance

The difference between extreme permissible dimensions that a part may have and still be acceptable.

AN350

The part number identifying a wing nut.

Standard steel bolts

Aircraft bolts identified by an asterisk or cross marked on the bolt head.

Torque conversion

$600$ inch-pounds of torque is equal to $50$ foot-pounds.

Castle tension nut alignment

If cotter pin holes do not align within the torque range, the acceptable practice is to change washers and try again.

NDT technician

A person certified at Level I or higher who is authorized to perform inspections such as Ultrasonic or Eddy Current.

2024 aluminum alloy bolt

An AN Aluminum Alloy bolt identified by two raised dashes on the head.

Alclad

A material consisting of pure aluminum surface layers on an aluminum alloy core.

Standard bolt orientation

Bolt shanks should be oriented Inboard, Down, and Aft, while heads should be Outboard, Up, and Forward.

Schematic diagram

A diagram used to explain a principle of operation and indicate the location of components with respect to each other within a system.

Thickness (feeler) gauge

A tool used to check the clearances between two surfaces.

Fayed surfaces

Surfaces that cause concern during chemical cleaning due to the danger of entrapping corrosive materials.

Stainless steel

Between 2024 aluminum alloy, zinc, and itself, this material is the most cathodic; it is also used for aircraft engine firewalls.

Machinist scale

A tool generally used to get a dimension from a divider.

Detail drawing

A description of a single part including dimensions and scale.

Assembly drawing

A description of an object made up of two or more parts.

Blending ratio

The ratio for blending an area where corrosion has been removed, specified as $20$ to $1$ length to depth.

Cold worked

A state where metals become strain or work hardened due to repeated mechanical force at room temperature.

Clean, dry threads

The thread condition to which torque values relate unless otherwise specified.

Bolt grip length

This dimension should be equal to the thickness of the material being fastened together to avoid a nut bottoming out.

Aluminum wool

A material used for general cleaning of aluminum surfaces by mechanical means.

Abrasive blasting

The most satisfactory corrosion removal method for high strength steel parts.

Severe pitting

According to AC 43-4A, a pit depth greater than $.010$ inch.

Gauge block

A tool used to calibrate a micrometer and check it for accuracy.

AN3DD5A

A bolt part number where the "3" indicates a diameter of $3/16$ of an inch.

Dwell time

A longer than normal penetrating time required when using dye penetrant to detect minute cracks.

Dial indicator

A tool used to measure the alignment of a rotor shaft or the plane of rotation of a disk.

Aliphatic Naphtha

A solvent used to clean acrylics and rubber.

Micrometer

A tool used to determine the amount of wear on a close tolerance bolt.

Hot linseed oil

A coating used to protect the interior surface of sealed structural steel tubing against corrosion.

Mercury

A substance that causes rapid and severe corrosion on aluminum that is very difficult to control.

Visual inspection

The most widely used nondestructive inspection technique, capable of detecting moderate surface corrosion.

Class 2 fit

A designation describing a free fit for threaded fasteners.