Sheet metal Flashcards
(143 cards)
1
Q
Select the alternative which best describes the function of the flute section of a twist drill
A
Forms the cutting edges of the drill point
2
Q
Rivet gauge, or transverse pitch is the distance between the
A
Centers of rivets in adjacent rows.
3
Q
Clad aluminum alloys are used in aircraft because they
A
Have surface layers of pure aluminum or aluminum alloy bonded to the core material to inhibit corrosion.
4
Q
MS20426AD-6-5 indicates a countersunk rivet which has
A
An overall length of 5/16 inch.
5
Q
Which rivet is used for riveting nickel-steel alloys?
A
Monel
6
Q
What should be the included angle of a twist drill for soft metals?
A
90 degrees
7
Q
The monocoque fuselage relies largely on the strength of
A
skin or covering
8
Q
The length of a rivet to be used to join a sheet of .032 inch and .064 inch aluminum alloy should be equal to
A
One and one half times the rivet diameter plus .096 inch
9
Q
A piece of stuck that is to be bent to a closed angle of 15 degrees must be bent through an angle of
A
165 degrees
10
Q
(Refer to figure 7.) What is dimension F? Setback at D = .095 Setback at E = .068 Bend allowance at D = .150 Bend allowance at E = .112
A
5.936
11
Q
What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric?
A
Warp clock (or compass)
12
Q
Cabin upholstery materials installed in current standard category airplanes must
A
Be at least flame resistant.
13
Q
When an MS20470D rivet is installed, its full shear strength is obtained
A
Only after a period of age hardening.
14
Q
When conducting a tap test on a composite panel, which of the following sounds would indicate delamination?
A
Dull thud
15
Q
(Refer Figure 1.) Which of the rivets shown will accurately fit the conical depression made by a 100 degree countersink?
A
1
16
Q
Which of the following drill bit types work best when drilling an aramid fiber (kevlar) composite laminate?
A
Carbide W-point
17
Q
The primary alloying agent of 2024-T3 is indicated by the number
A
2
18
Q
A well-designed rivet joint will subject the rivets to
A
Shear loads
19
Q
What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?
A
Bleader
20
Q
A category of plastic material that is capable of softening or flowing when reheated is described as a
A
Thermoplastic
21
Q
A main difference between lockbolt/huckbolt tension and shear fasteners (other than their application) is in the
A
Number of locking collar grooves
22
Q
Mild steel rivets are used for riveting
A
steel parts
23
Q
Which of the following are generally characteristics of carbon/graphite fiber composites?
1) Flexibility
2) Stiffness
3) High Compression Strength
4) Corrosive effect in contact with aluminum
5) Ability to conduct electricity
A
2,3, and 4
24
Q
One of the best ways to assure that a properly prepared batch of matrix resin has been achieved is to
A
Have mixed enough for a test sample
25
If it is necessary to compute a bend allowance tables are not available, the neutral axis of the bend can be
Found by adding approximately one-half of the stock thickness to the bend radius.
26
What type of bit should be used to drill holes in plexiglass?
A specifically modified twist drill
27
Repairing advanced composites using materials and techniques traditionally used for fiberglass repairs is likely to result in
An unairworthy repair
28
Which of the following, when added to wet resins, provide strength for the repair of damaged fastener holes in composite panels?
1) Microballoons
2) Flux
3) Chopped Fibers
2 and 3
29
Which is an identifying characteristic of acrylic plastics?
Zinc chloride will have no effect
30
Fiberglass damage that extends completely through a laminated sandwich structure
May be repaired
31
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.
32
The general rule for finding the proper rivet diameter is
Three times the thickness of the thickest sheet
33
What type loads cause the most rivet failures?
Shear
34
Under certain conditions, type A rivets are not used because of their
low strength characteristics
35
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
36
When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate
Separation of the laminates
37
What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?
To retard age hardening
38
Which of these methods may be used to inspect fiberglass/honeycomb structures of entrapped water?
1) Acoustic emission monitoring
2) x-ray
3) backlighting
2 and 3
39
On a sheet metal fitting layout with a single bend, allow for stretching by
Subtracting the setback from both legs
40
Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture
2
41
What is the minimum spacing for a single row of aircraft rivets
Three times the diameter of the rivet shank
42
When drilling stainless steel, the drill used should have an included angle of
140 degrees and turn at a low speed
43
(Refer to figure 4.) The amount of material required to make the 90 degree bend is
0.3436 inch
44
Sandwich panels made of metal honeycomb construction are used on modern aircraft because this type of construction
Has a high strength to weight ratio.
45
Rivet pitch is the distance between the
Centers of adjacent rivets in the same row
46
What is the purpose of a gusset or gusset plate used in the constitution and repair of aircraft structures?
To join and reinforce intersecting structural members
47
When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?
Water only
48
Which of the following need not be considered when determining minimum rivet spacing?
Rivet length
49
Alloy 2117 rivets are heat treated
By the manufacturer and do not require heat treatment before being driven.
50
When making repairs to fiberglass, cleaning of the area to be repairs is essential for a good bond. The final cleaning should be made using
MEK (methyl ethyl ketone)
51
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud diameter is measured in
sixteenths of an inch
52
The coefficient of expansion of most plastic enclosure materials is
Greater than both steel and aluminum
53
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 form the atmosphere
54
A single-loop 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 inch
55
When comparing the machining techniques for stainless steel sheet material to those for aluminum alloy sheet, it is normally considered considered good practice to drill the stainless steel at a
Lower speed with more pressure applied to the drill
56
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
5/16 inch
57
Fiberglass laminate damage that extends completely through one facing and into the core
Requires the replacement of the damaged core and facing
58
Joggles in removed rivet shanks would indicate partial
Shear failure
59
The preferred way to make permanent repairs on composites is by
Laminating on new repair plies
60
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
1/4 inch
61
Composite fabric material is considered to be the strongest in what direction?
Warp
62
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
5/16 inch
63
(Refer to Figure 6.) What is dimension D?
Setback = .252
Bend allowance = .345
4.182
64
The flat layout or blank length of a piece of metal from which a simple L-shaped bracket 3 inches by 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
1/8 inch
65
The most important factors needed to make a flat pattern layout are
Radius, thickness, and degree of bend
66
Which rivet is used for riveting magnesium alloy structures
5056 aluminum
67
Metal fasteners used with carbon/graphite composite structures
Must be constructed of material such as titanium or corrosion resistant steel
68
The strength and stiffness of a properly constructed composite buildup depends primarily on
The orientation of the plies to the load direction.
69
How many of the following are benefits of using microballoons when making repairs to laiminated honeycomb panels?
1) Greater concentrations of resin in edges and corners
2) Improved strength to weight ratio
3) Less density
4) Lower stress concentrations
2,3, and 4
70
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
71
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
72
If no scratches are visible after transparent plastic enclosure materials have been cleaned, their surfaces should be
Covered with a thin coat of wax
73
The length of time that a catalyzed resin will remain in a workable state is called the
Pot life
74
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 that similar repairs to the upper surface.
75
The monocoque fuselage relies largely on the strength of
Skin or covering
76
Threaded rivets (rivnuts) are commonly used to
Attach parts or components with screws to sheet metal
77
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
78
What is the minimum edge distance allowed for aluminum alloy sing lap sheet splices containing
The minimum edge distance for the single row is equal to that for the multiple row.
79
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
80
A potted compound repair on honeycomb can usually be made on damages less than
1 inch diameter
81
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
82
The aluminum alloys used in aircraft construction are usually hardened by which method?
Heat treatment
83
Which is considered good practice concerning the installation of acrylic plastics?
When rivets are used, adequate space or other satisfactory means to prevent excessive tightening of the frame to the plastic should be provided.
84
Which rivet is used for riveting nickel-steel alloys?
Monel
85
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.
86
What type of bit should be used to drill holes in plexiglas?
A specifically modified twist drill
87
A factor which determines the minimum space between rivets is
The diameter of the rivets being used
88
Select the alternative which best describes the function of the flute section of a twist drill
Forms the cutting edges of the drill point
89
(Refer to Figure 3.) Which is the grip length of the flush rivet?
3
90
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
Neutral line
91
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.
92
When straightening members made of 2024-T4, you should
Straighten cold and reinforce
93
If a streamline cover plate is to be hand formed using a form bock, 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.
94
(Refer to Figure 6.) Determine the dimensions of A, B, and C in the flat layout.
Setback = .252
Bend allowance = .345
A = .748, B = 1.496, C = 1.248
95
The sharpest bend that can be placed in apiece of metal without critically weakening the part is called the
Minimum radius of the bend
96
The shop head of a rivet should be
One and one-half times the diameter of the rivet shank.
97
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.
98
Which part of 2024-T3 aluminum alloy indicates the temper designation?
T3
99
A DD rivet is heat treated before use to
Soften to facilitate riveting
100
On a semimonocoque fuselage, the skin is reinforced by longitudinal structural members called
Longerons and stringers
101
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
102
A rivet set used to drive MS20470 rivets should
Have a slightly greater radius than the rivet head
103
The dimensions of an MS20430AD-4-8 rivet are
1/8 inch in diameter and 1/2 inch long
104
Most rivets used in aircraft construction have
Dimples
105
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.
106
How does acoustic emission testing detect detetcs in composite materials?
By picking up the "noise" of any deterioration that may be present.
107
(Refer to Figure 5.) What is the flat layout dimension?
6.8 inches
108
Shallow scratches on sheet metal may be required by
Burnishing
109
The length of a rivet to be used to join a sheet of .032 inch inch and .064 inch aluminum alloy should be equal to
One and one-half times the rivet diameter plus .096 inch.
110
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.
2) The extent of separation damage in composite structures is most accurately measured by a ring (coin tap) test.
Regarding the above statements,
Only No.1 is true
111
The classification for high tensile strength fiberglass used in aircraft structures is
S-glass
112
The markings on the head of a Dzus fastener identify the
Body diameter, type of head, and length of the fastener.
113
Which of the following are generally characteristic 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
114
Which rivets should be selected to join two sheets of .032 inch aluminum?
MS20470AD-4-4
115
Which of the following drill bit types work best when drilling an aramid fiber (Kevlar) composite laminate?
Carbide W-point
116
A piece of sheet metal is bent to a certain radius . The curvature of the bend is referred to as the
Bend radius
117
(Refer to Figure 4.) The length of flat A is
3.750 inches
118
The part of a replacement honeycomb core that must line up with the adjacent original is the
Ribbon direction
119
A potted compound repair on honeycomb can usually be made on damages less than
1 inch in diameter
120
One of the main advantages of Hi-lok type fasteners over earlier generations is that
They can be installed with ordinary hand tools.
121
Cabin upholstery materials installed in current standard category airplanes must
Be at least flame resistant
122
What is the most common method of cementing transport plastics
Soak method
123
Aircraft structural units, such as spars, engine supports etc, which have been built up from sheet metal, are normally
Repairable, using approved methods.
124
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.
125
You can distinguish between aluminum and aluminum alloy by
Testing with a 10 percent solution of caustic soda.
126
What is the minimum edge distance for aircraft rivets?
Two times the diameter of the rivet shank
127
(Refer to Figure 2.) Select the preferred drawing for proper countersinking
1
128
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.
129
Which part(s) of a semi-monocoque fuselage prevent(s) tension and compression from bending the fuselage?
Longerons and stringers
130
Heat-treated rivets in the D and DD series that are not driven within the prescribed time after treatment of removal from refrigeration
Must be reheat treated before use.
131
Rivet gauge, or transverse pitch is the distance between the
Centers of rivets in adjacent rows.
132
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.
133
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.
134
What should be the included angle of a twist drill for hard metal?
118 degrees.
135
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.
136
The classification for fiberglass reinforcement material that has high resistivity and is the most common is
E-glass
137
The general rule for finding the proper rivet diameter is
Three times the thickness of the thickest sheet
138
How many MS20470 AD-4-6 rivets will be required to attach a 10x5 inch plate, using a single row of rivets, minimum edge distance, and 4D spacing?
56
139
The installation of cherry mac and olympic-Lok rivets is accomplished by utilizing
A pulling tool
140
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.
141
The strength and stiffness of a properly constructed composite buildup depends primarily on
The orientation of the plies to the load direction.
142
Parts fabricated from Alclad 024-T3 aluminum sheet stock must have all
Scratches, kinks, tool marks, nicks, etc., must be held to a minimum.
143
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud length is measured in
Hundredths of an inch.
