Combined Materials and Precision Set for Generals 1 unit 3

Wood

Not still commonly used in aircraft construction.

Plastics

Have many applications in modern aircraft such as decorative trim and windows.

Heat

The two major classes of transparent plastic materials used in aircraft construction are classified according to their reaction to _.

Thermoplastic

These plastics soften when heated and harden when cooled.

Thermoplastic

These materials can be heated until soft and then formed into the desired shape a number of times without changing their chemical composition.

Thermosetting

These plastics harden upon heating and cannot be reshaped once heat-cured.

Laminated

_ plastics is superior to solid plastics and is used in pressurized aircraft due to its shatter-resistant qualities.

Monolithic

Solid plastics.

Masking paper

Applied to transparent plastic, may be removed by placing in an oven at 250 for 1 minute.

Aliphatic naphtha

May be applied to the masking paper of transparent plastics to remove it.

Composites

Can be very harmful to skin, eyes, and lungs.

Composites

Have the higher strength-to-weight ratio (C/M)

Composites

Transfer of stress allowed by chemical bonding (C/M).

Composites

Stiffness-to-density ratio (modulus) is higher (C/M).

Composites

Longer lifespan (C/M).

Composites

Higher corrosion resistance (C/M).

Composites

Higher tensile strength (4-6x) (C/M).

Composites

Greater design flexibility (C/M).

Compoisites

Don’t need joints or fasteners (C/M).

Metals

Inspection methods easier to conduct (C/M).

Metals

Have a long-term design database—older technology methods (C/M).

Metals

Cost advantage (C/M).

Metals

Have a standardized system of methodology for construction and repairs (C/M).

Metals

Often less toxic or hazardous (C/M).

Fibers particles whiskers

Three main forms of fiber reinforcement.

Laminate

Its core can be made from nearly anything (foam, wood, metal, paper)

Reinforced plastic

Dielectric properties make it ideal for radomes.

Natural rubber

Better physical properties of rubber, but deteriorates more rapidly.

Natural rubber

Type of rubber used as a sealing material for water methanol systems.

Butyl

Hydrocarbon rubber that resists oxygen, alkalies, oils, ozone,B and weathering.

Butyl

The rubber used with Skydrol, silicone fluids, gases, ketones, and acetones.

Buna-S

This rubber is used for tires and tubes.B

Buna-N

Used for oil and gasoline hoses, tank linings, gaskets, and seals.

Neoprene

Worse tensile strength, elongation, abrasion resistance, and distortion recovery than natural rubber.

Neoprene

Superior resistance to oil, poor to aromatic gasoline.

Neoprene

Used primarily for weather seals, window channels, bumper pads, oil-resistant hose, and carburetor diaphragms.

Neoprene

Used with Freon and silicate ester lubricants.

Thiokol

Polysulfide rubber: highest resistance to deterioration, but lowest physical properties.

Silicone

Rubbers made from Si, O, H, and C with good resistance to oils.

Silastic

Dielectric rubber used to insulate electrical and electronic equipment.

Date of manufacture

Color-coded jacket on shock cords and bungees represents the _ _ _.

Gaskets packings wipers

Three classes of seals.

O-rings

Should be rejected for flaws such as nicks and cracks.

V-ring and U-ring

Must be installed with V or lip facing toward the pressure.

Gaskets

Static seals between flat surfaces

Wipers

Used to clean and lubricate piston shafts and keep out dirt.

Sealing compounds

Come in two types, one part or two-part.

Two-part sealants

Should be weighed prior to mixing

77

Ideal temperature in F for curing most sealants.

Curing

May be accelerated by application of heat less than 120F.

FAA AC 43-4

Where you would find more in-depth information on the subject of aircraft corrosion.

Direct or electrochemical

Metal corrosion is the deterioration of metal by _ or _ attack.

Aluminum and Magnesium

The two most active metals.

15 days

How often should aircraft in severe climate zones be cleaned, inspected, and lubricated?

Electrochemical

Preventing this is done by eliminating one of the four condition required for this type of corrosion to occur.

Nobility

A measure of how electrically active a metal is.

Anode

On the nobility chart, it is the end most likely to corrode.

Cathode

On the nobility chart, it is the end least likely to corrode.

Intergranular

This type of corrosion may exist without any visible surface evidence.

Intergranular

High Strength aluminum alloys are more susceptible to this type of corrosion if they are not properly heat treated.

Shot peening

A method of increasing the resistance of a metal to stress corrosion cracking by creating compressive stresses on the surface of the metal.

Cyclic fatigue

A metal’s resistane to this may be reduced in a corrosive environment.

Galvanic

This type of corrosion is related to the size of the parts in contact.

Acids alkalies salts

Three most common corrosive agents are _ _ and _ but atmosphere and water may also act as corrosive agents.

Visual inspection

The most widely used technique for the detection and evaluation of corrosion.

Surface

Uniform etch or uniform attack; the most common type of corrosion.

Filiform

Oxygen concentration cell occurring on metal surfaces with an organic coating system.

Filiform

Recognized by worm-like traces of corrosion products beneath the paint film.

Pitting

First noticeable as a white or gray powdery deposit blotching the surface.

Dissimilar metal

Can cause pitting; also known as galvanic.

Metal ion Oxygen Active-passive

Three types of Concentration Cell Corrosion.

Intergranular

An attack along the grain boundaries of an alloy.

Exfoliation

The advanced form of intergranular corrosion.

Eddy current and ultrasonic

Used to detect intergranular corrosion.

Fretting

When two surfaces fit tightly together but can move relative to one another, it causes this type of corrosion.

Fatigue

Involves cyclic stress and a corrosive environment.

Galvanic

Dissimilar metals making electrical contact in the presence of an electrolyte.

Piano hinges

Prime spots for corrosion due to the materials they are made from and the fact they are natural traps for dirt, salts, and moisture.

Helicopter rotor heads and gearboxes

Require frequent corrosion inspections due to their high strength and exposure to the elements.

Chemical or mechanical

Two methods of removing corrosion; depends on the metal and degree of corrosion.

Rust

A metal oxide that does not protect the underlying base metal from further corrosion.

High strength steel parts

You may not use chemical corrosion removers on these without prior approval.

Chemical surface treatment

You may partially restore a damaged anodized aluminum surface with a _ _ _.

Magnesium

You may not use aluminum wool or other metallic cleaning products to clean _ parts.

Negligible patch insertion replacement

Four degrees of corrosion damage: _ damage, needs _, needs _, or needs _.

Anodic

These aluminum coatings provide corrosion resistance and a paint bonding surface.

Cleaning

A regular part of aircraft maintenance.

Aliphatic naphtha

Recommended for wiping down cleaned surfaces before painting.

Aliphatic naphtha

Suitable for cleaning acrylics and rubber.

Bicarbonate soda

Can be used to neutralize acid deposits in lead-acid battery compartments.

Fayed surface

Surface area contact between two overlapping parts.

Anodic

This type of metal will give up electrons most easily.

Electrolyte

A chemical liquid or gas which will conduct electrical current by releasing ions to unite with ions on electrodes

Alodizing

When a non-electrolytic chemical treatment for aluminum alloys is used to increase corrosion resistance and paint-bonding.

Heat treatment

Poor _ _ is a primary cause of intergranular corrosion.

Hydrogen embrittlement

Non-approved cleaning compounds can cause _ _ in metal structures when used to wash aircraft.

Anodizing

The electrolytic treatment for aluminum alloys to increase corrosion resistance

Corrosion

Can be caused by using caustic cleaning products on aluminum structures.

Boric acid

Used to neutralize corrosion of a ni-cad battery.