Airframe- M3 Structures & Application
Shallow scratches in sheet metal may be repaired by
Burnishing.
What is generally the best procedure to use when removing a solid shank rivet?
Drill to the base of the manufactured head with a drill one size smaller than the rivet shank and remove the rivet with a punch.
What 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 someof the rivets on an aircraft?
Fretting corrosion is occuring between the rivets and the skin.
What statement is true regarding the inspection of a stressed skin metal wing assembly known to have been critically loaded?
If genuine rivet tipping has occured, groups of consectutive rivet heads will be tipped in the same direction.
Longitudinal (fore and aft) structural members of a semi-monocoque fuselage are called
Londerons and stringers.
What part(s) of a semi-monocoque fuselage prevent(s) tension and compression from bending the fuselage?
Longerons and stringers.
Under certain conditions, type A rivets are not used because of their
Low strength characteristics
What rivets should be selected to join two sheets of .032-inch aluminum?
MS20470AD-4-4
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.
What's not to be considered when determining minimum rivet spacing?
Rivet Length
What type loads cause the most rivet failures?
Shear.
Mild steel rivets are used for riveting
Steel parts.
(Refer to Figure 2.) Select the preferred drawing for proper countersinking
1
(refer to Figure 1.) What rivets shown will accurately fit the conical depression made by a 100 Degree countersink?
1
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.
What should be the included angle of a twist drill for hard metal?
118 degrees
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
When drilling stainless steel, the drill used should have an included angle of
140 degrees and turn aat a low speed
The primary alloying agent of 2024-T3 is indicated by the number
2
What part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture?
2
What rivet may be used as recieved without further treatment?
2117-T3
(Refer to Figure 3.) What is the grip length of the flush rivet?
3
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.
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, drill with a No. 30 drill, is
5/16 inch.
What rivet is used for riveting magnesium alloy structures?
5056 aluminum
How many MS20470 AD-4-6 rivets will be required attach a 10" x 5" plate, using a single row of rivets, minimum edge distance, and 4D spacing?
56
What should be the included angle of a twist drill for soft metals?
90 Degrees.
What 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.
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
What prodecure 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
MS20426AD-6-5 indicates a countersunk rivet which has
an overall length of 5/16 inch
Clad aluminium alloys are used in aircraft becuase they
are less subject to corrosion than uncoated aluminum alloys.
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.
A factor which determines the minimum space between rivets is the
diameter of the rivets being used.
Most rivets used in aircraft construction have
dimples
A rivet set used to drive MS20470 rivets should
have a slightly greater radius than the rivet head.
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
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 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.
When an MS20470D rivet is installed, its full shear strength is obtained
only after a period of age hardening.
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.
Aircraft structural units, such as spars, engine supports, etc., what have been built up from sheet metal are normally
repairable, using approved methods.
Parts fabiricated from Alclad 2024-T3 aluminum sheet stock must have all
scratches, kinks, tool marks, nicks, etc., held to a minimum.
Joggles in removed rivet shanks would indicate partial
shear failure
The monocoque fuselage relies largely on the stregth of
skin or covering.
A DD rivet is heat treated before use to
soften to facilitate riveting.
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.
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.
What rivet is used for riveting nickel-steel alloys?
Monel
What statement is true regarding a cantilever wing?
No external bracing is needed.
