Chapter 2 Airframe phase book
The flat layout or blank length of a piece of metal from which a simple L shaped bracket 3 inches by 1 inch is the be bent depends upon the radius if the desired bend. The bracket which will require the greatest amount of material is one which has a bend radius of
1/8 inch
The dimensions of an MS20430AD-4-8 rivet are
1/8 inch in diameter and ½ inches long
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
A piece of flat stock that is to be bent to a closed angle of 15 degrees must be bent through an angle of
165 degrees.
The primary alloying agent of 2024-T3 is indicated by the number
2
Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture
2
A sheet metal repair is to be made using two pieces of .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
Which rivet is used for riveting magnesium alloy structures?
5056 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
When fabricating parts from Alclad 2024-T3 aluminum sheet stock
All scratches, kinks, tool marks, nicks, etc., must be held to a minimum.
The purpose of a joggle is to
Allow clearance for a sheet or an extrusion
MS20426AD-6-5 indicates a countersunk rivet which has
An overall length of 5/16
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 of aluminum
Shallow scratches in sheet metal may be repaired by
Burnishing
A rivet set used to drive MS20470 rivets should
Have a slightly greater radius than the rivet head
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
Unless otherwise specified the radius of a bend is the
Inside radius of the metal being formed
Which rivets should be selected to join two sheets of .032 inch aluminum
MS20470AD 4-4
The sight line on a sheet metal flat layout to be bent in a cornice brake or box brake is measured and marked
One radius from the bend tangent line that is placed under the brake
A well designed rivet joint will subject the rivets to
Shear loads
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
Cherrymax and Olympic-Lok rivets
Utilize a pulling tool for installation
A factor which determines the minimum space between rivets is the
Diameter of the rivets being used
When an MS20470D rivet is installed, its full shear strength is obtained
Only after a period of age hardening
Threaded rivets (Rivnuts) are commonly used to
Attach part or components with screws to sheet metal
Rivet pitch is the distance between the
Centers of adjacent rivets in the same row
Rivet gauge, or transverse pitch is the distance between the
Centers of rivets in adjacent rows
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
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 approximately one half of the stock thickness to the bend radius
The aluminum alloys used in aircraft construction are usually hardened by which method?
Heat treatment
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
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
When riveting dissimilar metals together, what precautions must be taken to prevent an electrolytic action?
Place a protective separator between areas of potential electrical difference
REFER TO FIGURE 1 AND ANSWER 2-29 ON PAGE 2-9
REFER TO FIGURE 1 AND ANSWER 2-29 ON PAGE 2-9
REFER TO FIGURE 2 AND ANSWER QUESTION 2-55 ON PAGE 2-16
REFER TO FIGURE 2 AND ANSWER QUESTION 2-55 ON PAGE 2-16
REFER TO FIGURE 3 AND ANSWER QUESTION 2-42 ON PAGE 2-12
REFER TO FIGURE 3 AND ANSWER QUESTION 2-42 ON PAGE 2-12
REFER TO FIGURE 4 AND ANSWER QUESTION 2-76 ON PAGE 2-23
REFER TO FIGURE 4 AND ANSWER QUESTION 2-76 ON PAGE 2-23
REFER TO FIGURE 5 AND ANSWER QUESTION 2-77 ON PAGE 2-23
REFER TO FIGURE 5 AND ANSWER QUESTION 2-77 ON PAGE 2-23
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud diameter is measured in
Sixteenths of an inch
The identifying marks on the heads of aluminum alloy rivets indicate the
Specific alloy used in the manufacture of the rivets
Mild steel rivets are used for riveting
Steel parts
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
12/16 inch
When drilling stainless steel, the drill used should have an included angle of
140 degrees and turn at a low speed
Which rivet may be used as received without further treatment
2117-T3
What should be the included angle of a twist drill for soft metals?
90 degrees
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
The markings on the head of a Dzus faster identify
Body diameter, type of head, and length of the fastener
Alloy 2117 rivets are heat treated
By the manufacturer and do not require heat treatment before being driven
Most rivets used in aircraft construction have
Dimples
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud length is measured in
Hundredths of an inch
Annealing of aluminum
Removes stresses caused by forming
Aircraft structural units, such as spars, engine supports, etc., which have been built up from sheet metal, are normally
Repairable, using approved methods
What type loads cause the most rivet failures?
Shear
Joggles in removed rivet shanks would indicate partial
Shear failure
A DD rivet is heat treated before use to
Soften to facilitate riveting
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
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
Clad aluminum alloys are used in aircraft because they
Are less subject to corrosion than uncoated aluminum alloys
Select the alternative which best describes the function of the flute section of a twist drill.
Forms the cutting edges of the drill
What is indicated by a black smokey residue streaming back from some of the rivets on an aircraft?
Fretting corrosion is occurring between the rivets and the skin
Which rivet is used for riveting nickel steel alloys?
Monel
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
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
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
The length of a rivet to be used to join a sheet of 0.32 inch and .064 inch aluminum alloy should be equal to
One and one half times the rivet diameter plus .096 inch
REFER TO FIGURE 5 AND ANSWER QUESTION 2-78 ON PAGE 2-24
REFER TO FIGURE 5 AND ANSWER QUESTION 2-78 ON PAGE 2-24
REFER TO FIGURE 6 AND ANSWER QUESTION 2-79 ON PAGE 2-24
REFER TO FIGURE 6 AND ANSWER QUESTION 2-79 ON PAGE 2-24
REFER TO FIGURE 6 AND ANSWER QUESTION 2-80 ON PAGE 2-24
REFER TO FIGURE 6 AND ANSWER QUESTION 2-80 ON PAGE 2-24
REFER TO FIGURE 7 AND ANSWER QUESTION 2-81 ON PAGE 2-24
REFER TO FIGURE 7 AND ANSWER QUESTION 2-81 ON PAGE 2-24
Which of the following need not be considered when determining the minimum rivet spacing?
Rivet length
On a sheet metal fitting layout with a single bend, allow for stretching by
Subtracting the setback from both legs
You can distinguish between aluminum and aluminum alloy by
Testing with a 10 percent solution of caustic soda
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
The general rule for finding the proper rivet diameter is
Three times the thickness of the thickest sheet
What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treating
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
One of the main advantages of Hi-Lok type fasteners over earlier generations is that
They can be installed with ordinary hand tools
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
¼ inch
The sharpest bend that can be placed in a piece of metal without critically weakening the part is called
Minimum radius of bend
A piece of sheet metal is bent to a certain radius. The curvature of the bend is referred to as the
Bend radius
