ASA (Airframe) Sheet Metal and Non-Metallic Structures

What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?

Bleeder.

How does acoustic emission testing detect defects in composite materials?

By picking up the "noise" of any deterioration that may be present.

Which of the following drill bit types work best when drilling an aramid fiber (Kevlar) composite laminate?

Carbide W-point.

The classification for fiberglass reinforcement material that has high resistivity and is the most common is

E-glass.

Select the alternative which best describes the function of the flute section of a twist drill.

Forms the cutting edges of the drill point.

What is indicated by a black "smoky" residue streaming back from some of the rivets on an aircraft?

Fretting corrosion is occurring between the rivets and the skin.

Which statement is true regarding the inspection of a stressed skin metal wing assembly known to have been critically loaded?

If genuine rivet tipping has occurred, groups of consecutive rivet heads will be tipped in the same direction.

Longitudinal (fore and aft) structural members of a semi-monocoque fuselage are called

LONGerons and stringers.

Which part(s) of a semi-monocoque fuselage prevent(s) tension and compression from bending the fuselage?

Longerons and stringers.

When making repairs to fiberglass, cleaning of the area to be repaired is essential for a good bond. The final cleaning should be made using

M.E.K. (methyl ethyl ketone)

Which statement is true regarding a cantilever wing?

No external bracing is needed.

Repairs or splices involving stringers on the lower surface of stressed skin metal wings are usually

PERMITTED, BUT are normally more critical in reference to strength in tension than similar repairs to the upper surface.

What precaution, if any, should be taken to prevent corrosion inside of a repaired metal honeycomb structure?

Prime the repair with a corrosion inhibitor and seal from the atmosphere.

Which of the following need not be considered when determining minimum rivet spacing?

Rivet length.

The classification of high tensile strength fiberglass used in aircraft structures is

S-glass.

What is the most common method of cementing transparent plastics?

Soak method.

If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document?

TSO C22

What is the minimum edge distance allowed for aluminum alloy single lap sheet splices containing a single row of rivets as compared to a joint with multiple rows, all rivets being equal in diameter?

The minimum edge distance for the single row is equal to that for the multiple row.

What is one of the determining factors which permits machine countersinking when flush riveting?

Thickness of the material is greater than the thickness of the rivet head.

What is the minimum spacing for a single row of aircraft rivets?

Three times the diameter of the rivet shank.

What is the purpose of a gusset or gusset plate used in the construction and repair of aircraft structures?

To join and reinforce intersecting structural members.

What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?

To retard age hardening.

Which procedure is correct when using a reamer to finish a drilled hole to the correct size?

Turn the reamer only in the cutting direction.

What is the minimum edge distance for aircraft rivets?

Two times the diameter of the rivet shank.

Composite fabric material is considered to be the strongest in what direction?

Warp (or length)

What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric?

Warp clock (or compass)

When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?

Water only.

Which is considered good practice concerning the installation of acrylic plastics?

When rivets are used, adequate spacer or other satisfactory means to prevent excessive tightening of the frame to the plastic should be provided.

Which is an identifying characteristic of acrylic plastics?

Zinc chloride will have no effect.

The installation of Cherrymax and Olympic-Lok rivets is accomplished by utilizing

a pulling tool.

What type of bit should be used to drill holes in Plexiglass?

a specially modified twist drill.

Repairing advanced composites using materials and techniques TRADITIONALLY used for fiberglass repairs is likely to result in

an unairworthy repair.

Clad aluminum alloys are used in aircraft because they

are less subject to corrosion than uncoated aluminum alloys.

Threaded rivets (Rivnuts) are commonly used to

attach parts or components with screws to sheet metal.

Cabin upholstery materials installed in current standard category airplanes must

be AT LEAST flame resistant

The markings on the head of a Dzus fastener identify the

body diameter, type of head, and length of the fastener.

Shallow scratches in sheet metal may be repaired by

burnishing.

Alloy 2117 rivets are heat treated

by the manufacturer and do not require heat treatment before being driven.

Rivet gauge, or transverse pitch is the distance between the

center of rivets in adjacent rows.

Rivet pitch is the distance between the

centers of adjacent rivets in the same row.

If no scratches are visible after transparent plastic enclosure materials have been cleaned, their surfaces should be

covered with a thin coat of wax.

If an aircraft's transparent plastic enclosures exhibit fine cracks which may extend in a network over or under the surface or through the plastic, the plastic is said to be

crazing.

A factor which determines the minimum space between rivets is the

diameter of the rivets being used.

Fiberglass laminate damage not exceeding the first layer or ply can be repaired by

filling with a putty consisting of a compatible resin and clean, short glass fibers.

The coefficient of expansion of most plastic enclosure material is

greater than both steel and aluminum.

Sandwich panels made of metal honeycomb construction are used on modern aircraft because this type of construction

has a high strength to weight ratio.

A rivet set used to drive MS20470 rivets should

have a slightly greater radius than the rivet head.

One of the best ways to assure that a properly prepared batch of matrix resin has been achieved is to

have mixed enough for a test sample.

The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud LENGTH is measured in

hundredths of an inch.

The preferred way to make permanent repairs on composites is by

laminating on new repair plies.

Under certain conditions, type A rivets are not used because of their

low strength characteristics.

When comparing the machining techniques for stainless steel sheet material to those for aluminum alloy sheet, it is normally considered good practice to drill the stainless steel at a

lower speed with more pressure applied to the drill.

Fiberglass damage that extends completely through a laminated sandwich structure

may be repaired.

Metal fasteners used with carbon/graphite composite structures

must be constructed of material such as titanium or corrosion resistant steel.

Heat-treated rivets in the D and DD series that are not driven within the prescribed time after heat treatment or removal from refrigeration

must be reheat treated before use.

A main difference between Lockbolt/Huckbolt tension and shear fasteners (other than their application) is in the

number of locking collar grooves

The shop head of a rivet should be

one and one-half times the diameter of the rivet shank.

Superficial scars, scratches, surface abrasion, or rain erosion on fiberglass laminates can generally be repaired by applying

one or more coats of suitable resin (room temperature catalyzed) to the surface.

When MS20470D rivet is installed, its full shear strength is obtained

only after a period of age hardening.

(1) When performing a ring (coin tap) test on composites, a change in sound may be due to damage or to transition to a different internal structure. (2) The extent of separation damage in composite structures is most accurately measured by a ring (coin tap) test. Regarding the above statements,

only number 1 is true

Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the

possibility of causing delamination.

The length of time that a catalyzed resin will remain in a workable state is called the

pot life.

Aircraft structural units, such as spars, engine supports, etc., which have been built up from sheet metal, are normally

repairable, using approved methods.

Fiberglass laminate damage that extends completely through one facing and into the core

requires the replacement of the damaged core and facing.

The part of a replacement honeycomb core that must line up with the adjacent original is the

ribbon direction.

Parts fabricated from Alclad 2024-T3 aluminum sheet stock must have all

scratches, kinks, tool marks, nicks, etc. held to a minimum.

When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate

separation of the laminates.

A well-designed rivet joint will subject the rivets to

shear loads

The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud DIAMETER is measured in

sixteenths of an inch.

The monocoque fuselage relies largely on the strength of

skin or covering.

The identifying marks on the heads of aluminum alloy rivets indicate the

specific alloy used in the manufacture of the rivets.

When straightening members made of 2024-T4, you should

straighten cold and reinforce.

One method of inspecting a laminated fiberglass structure that has been subjected to damage is to

strip the damaged area of all paint and shine a strong light through the structure.

When balsa wood is used to replace a damaged honeycomb core, the plug should be cut so that

the grain is PERPENDICULAR to the skin.

The strength and stiffness of a properly constructed composite buildup depends primarily on

the orientation of the plies to the load direction.

When repairing a small hole on a metal stressed skin, the major consideration in the design of the patch should be

the shear strength of the riveted joint.

A category of plastic material that is capable of softening or flowing when reheated is described as a

thermoplastic.

One of the main advantages of Hi-Lok type fasteners over earlier generations is that

they can be installed with ordinary hand tools.

The general rule for finding the proper rivet diameter is

three times the thickness of the thickest sheet

When installing transparent plastic enclosures which are retained by bolts extending through the plastic material and self-locking nuts, the nuts should be

tightened to a firm fit, then backed off one full turn.

When repairing large, flat surfaces with polyester resins, warping of the surface is likely to occur. One method of reducing the amount of warpage is to

use short strips of fiberglass in the bonded repair.

Which of the following are generally characteristics of aramid fiber (Kevlar) composites? 1. High tensile strength 2. Flexibility 3. Stiffness 4. Corrosive effect in contact with aluminum 5. Ability to conduct electricity

1 and 2. High tensile strength and flexibility.

Proper pre-preg composite lay-up curing is generally accomplished by 1. applying external heat. 2. room temperature exposure. 3. adding a catalyst or curing agent to the resin. 4. applying pressure.

1 and 4. Applying external heat and pressure.

A potted compound repair on honeycomb can usually be made on damages less than

1 inch in diameter.

A sheet metal repair is to be made using two pieces of 0.040-inch aluminum riveted together. All rivet holes are drilled for 3/32-inch rivets. The length of the rivets to be used will be

1/4 inch

The dimensions of an MS20430AD-4-8 rivet are

1/8 inch in diameter and 1/2 inch long. Diameter in 32nds and length in 16ths.

When repairing puncture-type damage of a metal faced laminated honeycomb panel, the edges of the doubler should be tapered to

100 times the thickness of the metal.

What should be the included angle of a twist drill for HARD metal?

118 degrees (59 degrees on either side of center)

A single-lap sheet splice is to be used to repair a section of damaged aluminum skin. If a double row of 1/8-inch rivets is used, the minimum allowable overlap will be

13/16 of an inch

When drilling stainless steel, the drill used should have an included angle of

140 degrees and turn at a low speed.

Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture?

2 (the first number in 2017)

The primary alloying agent of 2024-T3 is indicated by the number

2 (the first number in 2024)

Which of the following, when added to wet resins, provide strength for the repair of damaged fastener holes in composite panels? 1. Microballons 2. Flox 3. Chopped fibers

2 and 3. Flox and chopped fibers

Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water? 1. Acoustic emission monitoring 2. X-ray 3. Backlighting

2 and 3. X-ray and backlighting

How many of the following are benefits of using microballoons when making repairs to laminated honeycomb panels? 1. Greater concentration of resin in the edges and corners. 2. Improved strength to weight ratio. 3. Less density. 4. Lower stress concentrations.

2, 3, and 4. Improved strength to weight ratio, less density, and lower stress concentrations.

Which of the following are generally characteristic of carbon/graphite fiber composites? 1. Flexibility 2. Stiffness 3. High compressive strength 4. Corrosive effect in contact with aluminum 5. Ability to conduct electricity

2, 3, and 4. Stiffness, high compressive strength and corrosive effect in contact with aluminum.

How many MS20470 AD-4-6 rivets will be required to attach a 10 x 5 inch plate, using a single row of rivets, minimum edge distance, and 4D spacing?

56

Which fiber to resin (percent) ratio for advanced composite wet lay-ups is generally considered the best for strength?

60:40 (60% fiber to 40% resin)

What should be the included angle of a twist drill for SOFT metals?

90 degrees. (45 degrees on either side of center)

Which is correct concerning the use of a file?

Apply pressure on the forward stroke, only, except when filing very soft metals such as lead or aluminum.