A well-designed rivet joint will subject the rivets to
A main difference between Lockbolt/Huckbolt tension and shear fasteners (other than their application) is in the
Number of locking collar grooves
Alloy 2117 rivets are heat treated
by the manufacturer and do not require heat treatment before being driven.
The general rule for finding the proper rivet diameter is
Three time the thickness of the thickest sheet.
The shop head of a rivet should be
one and one-half times the diameter of the rivet shank.
One of the main advantages of Hi-Lok type fasteners over earlier generations is that
they can be installed with ordinary hand tools.
The markings on the head of a Dzus fastener identify the
Body Diameter, type of head, and length of the fastener.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud length is measured in
hundrenths of an Inch.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud diameter is measured in
Sixteenths of an Inch
Threaded rivets (Rivnuts) are commonly used to
attach parts or components with screws to sheet metal.
Cherrymax and Olympic-Lok rivets
Utilize a pulling tool for installation.
Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the
Posibility of causing delamination.
Metal fasteners used with carbon/graphite composite structures
must be constructed of material such as titanium or corrosion resistant steel.
Sandwich panels made of metal honeycomb construction are used on modern aircraft because this type of construction
Has a higher strength to weight ratio.
(1) When performing a ring (coin tap) test on composite structures, a change in sound may be due to damage or to transition to a different internal structure.
Only No. 1 is True
Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water?
2 and 3
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.
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 material.
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.
Composite inspections conducted by means of acoustic emission monitoring
pick up the noise of 'Noise' of corossion or other deterioration occuring.
What precaution, if any, should be taken to prevent corrosion inside a repaired metal honeycomb structure?
Prime the repair with a corrosion inhibitor and seal from the atmosphere.
One method of inspecting a laminated fiberglass structure that has been subjected to damage is to
Strip the damage area of all paint and shine a strong light through the structure.
When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate
seperation of laminates
How many of the following are benefits of using microballoons when making repairs to laminated honeycomb panels?
2. Improved strength to weight ratio.
3. Less density
4. Lower stress concentrations
2, 3, and 4
The length of time that a catalyzed resin will remain in a workable state is called the
A category of plastic material that is capable of softening or flowing when reheated is described as a
The classification for high tensile strength fiberglass used in aircraft structures is
Which is an identifying characteristic of acrylic plastics?
Zinc Chloride will have no effect
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.
The classification for fiberglass reinforcement material that has high resistivity and is the most common is
A potted compound repair on honeycomb can usually be made on damages less than
1 inch in diameter
Composite fabric material is considered to be the strongest in what direction?
What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric?
Warp Clock (or Compass)
The strength and stiffness of a properly constructed composite buildup depends primarily on
the orientation of the plies to the load direction
Which fiber to resin (percent) ratio for advanced composite wet lay-ups is generally considered the best for strength?
What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?
Proper pre-preg composite lay-up curing is generally accomplished by
1. applying external heat.
4. applying pressure.
1 and 4
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.
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
MEK ( Methyl Ethyl Ketone)
When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?
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.
Fiberglass damage that extends completely through a laminated sandwich structure
May be Repaired.
Fiberglass laminate damage that extends completely through one facing and into the core
Requires the replacement of the damaged core and facing.
Repairing advanced composites using materials and techniques traditionally used for fiberglass repairs is likely to result in
An unairworthy repair.
The preferred way to make permanent repairs on composites is by
lamintating on new repair plies
Which of the following, when added to wet resins, provide strength for the repair of damaged fastener holes in composite panels?
3. Chopped fibers.
2 and 3
The part of a replacement honeycomb core that must line up with the adjacent original is the
Which of the following are generally characteristic of aramid fiber (Kevlar) composites?
1. High tensile strength.
1 and 2
Which of the following are generally characteristic of carbon/graphite fiber composites?
3. High compressive strength.
4. Corrosive effect in contact with aluminum.
2, 3, and 4
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
When installing transparent plastic enclosures which are retained by bolts extending through the plastic material and self-locking nuts, the nuts should be
tighten to a firm fit, and backed off one full turn.
If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document?
Which is considered good practice concerning the installation of acrylic plastics?
When rivets are used, adequate spacer or satisfactory means to prevent excessive tightening of the frame to the plastic should be provided.
The coefficient of expansion of most plastic enclosure materials is
greater than both steel and aluminum
If no scratches are visible after transparent plastic enclosure materials have been cleaned, their surfaces should be
covered with a thin coat of wax.
Cabin upholstery materials installed in current standard category airplanes must
be at least flame resistant
What is the most common method of cementing transparent plastics?
When holes are drilled completely through Plexiglas, a
specially modified twist drill should be used.
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.
Select the alternative which best describes the function of the flute section of a twist drill.
Forms the cutting edges of drill points.
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?
Longitudinal (fore and aft) structural members of a semi-monocoque fuselage are called
longerons and stringers
Shallow scratches in sheet metal may be repaired by
What should be the included angle of a twist drill for soft metals?
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.
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
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.
What is the minimum edge distance for aircraft rivets?
Two times the diameter of the rivet shank.
When drilling stainless steel, the drill used should have an included angle of
140 degrees and turn at a low speed.
What is the minimum spacing for a single row of aircraft rivets?
Three times the diameter of the rivet shank.
(Refer to Figure 1.) Which of the rivets shown will accurately fit the conical depression made by a 100° countersink?
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.
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.
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.
Which procedure is correct when using a reamer to finish a drilled hole to the correct size?
Turn the reamer in the cutting directions.
Repairs or splices involving stringers on the lower surface of stressed skin metal wings are usually
permitted but are normaly more critical in reference to strength in tension than similar repairs to the upper surface.
When straightening members made of 2024-T4, you should
straighten cold and reinforce
Clad aluminum alloys are used in aircraft because they
are less subject to corrosion than uncoated aluminum alloys.
Which statement is true regarding a cantilever wing?
No external Bracing is needed.
Aircraft structural units, such as spars, engine supports, etc., which have been built up from sheet metal, are normally
repairable, using approved methods
A factor which determines the minimum space between rivets is the
Diameter of the rivets being used.
What should be the included angle of a twist drill for hard metal?
When fabricating parts from Alclad 2024-T3 aluminum sheet stock,
All scratches, kinks, tool marks, nicks, ect. must be held to a minimum.
The monocoque fuselage relies largely on the strength of
Skin or Covering
Which part(s) of a semi-monocoque fuselage prevent(s) tension and compression from bending the fuselage?
Longerons and Stringers
Rivet gauge, or transverse pitch is the distance between the
center of rivets in adjacent rows
Rivet pitch is the distance between the
center of adjacent rivets in the same row
(Refer to Figure 2.) Select the preferred drawing for proper countersinking.
What is indicated by a black 'smoky' residue streaming back from some of the rivets on an aircraft?
Fretting corrosion is occuring between the rivets and the skin.
The identifying marks on the heads of aluminum alloy rivets indicate the
specific alloy used in manufacture of the rivets.
When an MS20470D rivet is installed, its full shear strength is obtained
only after a period of age hardening.
Which of the following need not be considered when determining minimum rivet spacing?
What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?
To retard age hardening.
Under certain conditions, type A rivets are not used because of their
Low strength characteristics.
A rivet set used to drive MS20470 rivets should
Have a slightly greater radius than the rivet head.
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
The dimensions of an MS20430AD-4-8 rivet are
1/8 in diameter and 1/2 inch long
The primary alloying agent of 2024-T36 is indicated by the number
Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture?
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
Most rivets used in aircraft construction have
MS20426AD-6-5 indicates a countersunk rivet which has
An overall length of 5/16 inch.
Which rivet may be used as received without further treatment?
2117 - T3
(Refer to Figure 3.) Which is the grip length of the flush rivet?
Which rivets should be selected to join two sheets of .032-inch aluminum?
A sheet metal repair is to be made using two pieces of 0.0625-inch aluminum riveted together. All rivet holes are drilled for 1/8-inch rivets. The length of the rivets to be used will be
Mild steel rivets are used for riveting
A DD rivet is heat treated before use to
soften to facilitate riveting
When riveting dissimilar metals together, what precautions must be taken to prevent an electrolytic action?
Place a protective seperator between the areas of potential electrical difference.
The length of a rivet to be used to join a sheet of .032-inch and .064-inch aluminum alloy should be equal to
one and one-half times the rivet diameter plus .096 inch.
What is generally the best procedure to use when removing a solid shank rivet?
Drill to the base of the manufactured rivet head with a drill one size smaller than the rivet shank and remove the rivet with a punch.
Joggles in removed rivet shanks would indicate partial
What type loads cause the most rivet failures?
Which rivet is used for riveting magnesium alloy structures?
Which rivet is used for riveting nickel-steel alloys?
The length of rivet to be chosen when making a structural repair that involves the joining of 0.032-inch and 0.064-inch aluminum sheet, drilled with a No. 30 drill, is
(Refer to Figure 4.) The length of flat A is
(Refer to Figure 4.) The amount of material required to make the 90° bend is
(Refer to Figure 5.) What is the length of flat A?
(Refer to Figure 5.) What is the flat layout dimension?
If a streamline cover plate is to be hand formed using a form block, a piece of dead soft aluminum should first be placed over the hollow portion of the mold and securely fastened in place. The bumping operation should be
Started by tapping the aluminum lightly around the edges and gradually working down into the center.
A piece of flat stock that is to be bent to a closed angle of 15° must be bent through an angle of
When a piece of aluminum alloy is to be bent using a minimum radius for the type and thickness of material,
the layout should be made so that the bend will be 90 degrees to the grain of the sheet.
The flat layout or blank length of a piece of metal from which a simple L-shaped bracket 3 inches by 1 inch is to be bent depends upon the radius of the desired bend. The bracket which will require the greatest amount of material is one which has a bend radius of
If it is necessary to compute a bend allowance problem and bend allowance tables are not available, the neutral axis of the bend can be
Found by adding aproximately one-half of stock thickness to the bend radius.
Unless otherwise specified, the radius of a bend is the
inside radius of the metal being formed.
The sharpest bend that can be placed in a piece of metal without critically weakening the part is called the
minimum radius of bend
The most important factors needed to make a flat pattern layout are
radius, thickness, and degree of bend.
A piece of sheet metal is bent to a certain radius. The curvature of the bend is referred to as the
You can distinguish between aluminum and aluminum alloy by
testing with a 10 percent solution of caustic soda
The purpose of a joggle is to
allow clearance for a sheet or an extrusion
When bending metal, the material on the outside of the curve stretches while the material on the inside of the curve compresses. That part of the material which is not affected by either stress is the
(Refer to Figure 6.) Determine the dimensions of A, B, and C in the flat layout.Setback = .252Bend allowance = .345
A = .748, B = 1.496, C = 1.248
(Refer to Figure 6.) What is dimension D?Setback = .252Bend allowance = .345
The sight line on a sheet metal flat layout to be bent in a cornice or box brake is measured and marked
one radius from the bend tangent line that is placed under the brake.
(Refer to Figure 7.) What is dimension F?Setback at D = .095Setback at E = .068Bend allowance at D = .150Bend allowance at E = .112
On a sheet metal fitting layout with a single bend, allow for stretching by
subracting the setback from both legs.
The aluminum alloys used in aircraft construction are usually hardened by which method?