BLOCK 5 WELDING AND SHEET METAL

Which of the rivets shown will accurately fit the conical depression made by a 100%? (refer to figure 1)

1

The shop head of a rivet should be?

1 and 1/2 times the diameter of the rivet shank.

The length of the revit to be used to join a sheet of 0032 inch and .064 inch aluminum alloy should be equal to?

1 and 1/2 times the diameter plus .096 inch

1.443

1.443

A sheet metal repair is to be made using 2 pieces of 0.040-inch aluminum riveted together, all rivet holes are drilled for 3/32-inch rivets the length of the rivets can be will be?

1/4 inch

The flat layout or blank length of a piece metal from which a simple L-shaped ___ inches by 1 inch is to be bent depends upon the the radius of a desired bend. The bend which will require the greatest amount of material is one which has the bend radius of?

1/8 inch

The dimensions of MS20430AD-4-8 rivet are?

1/8 inch in diameter and 1/2 inch long.

Apiece of flat stock that is to be bent to a closed angle of 15 degrees must be bent to an angle of?

165 degrees

The primary alloying agent of 2024-t36 is indicated by the number?

2

Which of the following can be welded without adversely affecting strength?

2

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

2

Which is the grip length of the flush rivet?9 refer to figure 3).

3

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

3 times the diameter of the rivet shank.

The general rule for finding the proper rivet diameter is?

3 times the thickness of the thickest sheet.

What is the length of flat A/ (refer to figure 5)

3.7 inches

(Refer to figure 4) the length of flat A is?

3.750

What is the dimension D? (refer to figure 6) setback=.252 bend allowance=.345

4.182

4.778

4.778

What is the dimension F? Setback at D=.095 Setback at E=.068Bend allowance at D=.150 Bend allowance at E=.112

5.936

A sheet metal repair is to be using 2 pieces of 0.625-inch aluminum riveted together, all rivet holes are drilled for 1/8 rivets, the length of the rivets to be used with be:

5/16 inch

The length f the 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 no. 30 drill bit is?

5/16 inch

Which rivet is used for riveting magnesium alloy structures.

5056 aluminum

What is the flat layout dimension? (refer to figure 5).

6.8 inches

A welding torch backfire may be caused by?

A loose tip.

Engine mount members should preferably be repaired by using?

A smaller diamter tube with fish mouth and rosette welds.

Determine the dimensions of A,B and C in the flat layout, Setback=.252 bend allowance=.345

A=1.252 B=2.504 C=1.752

Edge notching is generally recommended in butt welding above a certain thickness of aluminum because it.

Aids in getting full penetration of the metal and prevents local distortion.

The purpose of a joggle is to?

Allow clearance for a sheet or extrusion.

.065

.065

.109

.109

.157

.157

.218

.218

The amount of material required to make the 90 degree bend is?

0.3436 inch

What is the minimum edge distance for aircraft rivets?

2 times the diameter of the rivet head.

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.

Why should a carburizing flame be avoided when welding steel?

A cold weld could result.

A rivet set used to drive MS20470 rivets should:

Have a slightly greater radius then 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 rivets will be tipped in the same direction.

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

Longerons and stringers.

Which rivets should be selected to join 2 sheets of .032- inch aluminum?

MS20470AD-4-4

Which statement concerning a welding process is true?

The inert-arc welding uses an inert gas to protect the weld zone from the atmosphere.

2,335

2,335

When fabricating parts from Alclad-2024-T3 aluminum sheet rock:

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

MS20426AD-6-5 indicates a countersunk rivet, which has.

An overall length of 5/16 inch

Clad aluminum alloys are used in aircraft because they:

Are less subject to corrosion than uncoated aluminum alloys.

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

Welding over brazed or soldered joints is:

Not permitted.

When inspecting a butt-welded joint by visual means:

The penetration should be 100% of the thickness of the base metal.

Shallow scratches in sheet metal may be repaired by?

Burnishing

Most rivets used in aircraft construction have?

Dimples

Oxides form very rapidly when alloys or metals are hot, it is important, therefore when welding aluminum to use a:

Flux

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 approximately 1/2 of the stock thickness to the bend radius.

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

Fretting corrosion is occurring between the rivets and the skin.

The aluminum alloys used in aircraft construction are usually hardened by which method?

Heat treatment.

The shielding gases generally used in the Gas Tungsten Arc(GTA) welding of aluminum consist of?

Helium or Argon or a mixture of Helium or Argon.

Unless otherwise specified, the radius of a bend is the?

Inside radius of the metal being formed.

Acetelyne at a line pressure above 15psi.

Is dangerously unstable

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

Longerons and Stringers

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.

The most important consideration(s) when selecting a weldind rod is/are?

Material Compatiblity.

What purpose does Flux serve in welding aluminum?

Minimizes or prevents oxidation.

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 oxyacetylene flame for silver soldering should be?

Neutral

The acetelyne flame used for aluminum welding should be:

Neutral and Soft.

Which statement is true regarding Cantilever Wing?

No external bracing is needed.

The straight line on a sheet flat layout to be bent in cornice or box brake is measured and marked:

On a radius from the bend tangent line that is placed under the brake.

Where should the flux be applied when oxacetylene welding aluminum?

Painted on the surface to be welded and applied to the welding rod.

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, then similar repairs to the upper surface.

When riveting dissimilar metals together, what precautions must be taken to prevent electrolytic action?

Place a protective separator between the areas of potential electrical difference.

In Gas Tungsten Arc (GTA) welding a stream of inert gas is used to?

Prevents the formation of oxides in the puddle.

The most important factors needed to make a flat pattern layout are?

Radius, thickness and degree of bend.

Why are aluminum plated 1/4 inch usually preheated before welding?

Reduces internal stresses and assures more complete penetration.

Filing or Grinding a weld bend:

Reduces the strength of the joint.

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.

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

Rivet Length

A well designed rivet joint will subject the rivets to:

Shear Loads

In gas welding the amount of heat applied to the material being welded is controlled by the:

Size of the tip opening.

The monocoque fuselage relies largely on the strength of?

Skin and Covering.

How should a welding torch flame be adjusted to weld stainless steel?

Slightly Carbonizing.

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

Specific alloy used in the manufacture of the rivets.

Oxygen and acetylene cylinders are made of?

Steel

On a sheet of metal fitting layout with a single bend, allow for stretching by

Subtracting the setback from 1 leg.

In selecting a torch itp size to use in welding, the size of the tip opening determines the:

Temperature of the flame.

A piece of sheet metal is bent to a certain radius, the curvature of the bend is referred to as?

The Bend Radius

A factor which determines the minimum space between rivets is the?

The diameter of the rivets being used.

When a piece of aluminum alloy is to 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 rivet joint.

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

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

Which statement is true in regard to welding heat treated magnesium?

The welded section does not have the strength of the original metal.

Why isit necessary to use flux in all silver soldering operations?

To chemically clean the base metal oxide film.

Alloy 2117 rivets are heat treated:

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

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.

What type of loads cause the most rivet failures?

shear loads

Cylinders used to transport and store acetylene.

Are green in color.

Rivet Pitch is the distance between the?

Centers of the adjacent rivets in the same rows.

Rivet gauge, or transverse pitch is the distance between the?

Centers of the rivets in adjacent rows.

refer to figure 2- Select the preferred drawing for proper countersinking.

C