Sheet Metal & Non-Metallic Structures

Question 1

How do you determine the total length of a solid rivet for installation?

Answer 1

The grip length +1.5 x the rivet diameter.

Question 2

What is done with the rivet head stem when a self plugging rivet is installed?

Answer 2

The stem is pulled until it snaps off, and the remaining projecting part is trimmed flush with the head

Question 3

Give examples of self plug-in, mechanical lock rivets

Answer 3

Cherry LOC and Cherry Max or Hulk LOC

Question 4

What methods are used in forming sheet metal?

Answer 4

Shrinking, stretching, bumping, gripping, folding

Question 5

What factors are used to determine setback?

Answer 5

Bend radius and material thickness

Question 6

What calculation must be made with bending sheet metal?

Answer 6

Bend allowance and setback

Question 7

What must be done when two bends intersect to prevent cracking?

Answer 7

Relief holes are drilled at the intersection or corner

Question 8

What is a Joggle?

Answer 8

It’s the offset formed on a part to allow clearance for a sheet or another mating part

Question 9

What is the purpose of lightning holes cut in rib sections?

Answer 9

To reduce weight and increase stiffness

Question 10

Describe Rivet head markings for A, B, D, AD & DD rivets

Answer 10

A– are plain
B – have a cross
D – have a raised dot
AD - have a dimple
DD – double dash

Question 11

What are the correct dimensions on a properly formed rivet head?

Answer 11

1 1/2 the shank diameter and 1/2 of the diameter height

Question 12

How do you determine the proper material to be used for repair on an all metal aircraft?

Answer 12

Use the same type in thickness of the material that was used in the original structure

Question 13

What is the single row spacing an edge distance for protruding head rivets?

Answer 13

Edge 2D the diameter and its spacing is 3D the diameter of the rivet head

Question 14

Describe the criteria for a replacement of a 2024 rivet with a 2117 rivet for general repairs

Answer 14

For 5/32 or less diameter, use the next larger size rivet 2117 and the edge/spacing distance must meet the minimum requirements

Question 15

What is the major type of damage to aluminum structures that is caused by exposure to the weather?

Answer 15

Corrosion

Question 16

What is the difference between the tools required to pull Cherry Lock Rivet in a Cherry Max rivet?

Answer 16

Cherry LOCK - requires different pulling head for different sizes
Cherry MAX - same pulling head for different sizes

Question 17

How can a mechanic determine whether the counter sink for a flush or if it should be dimpled or drilled?

Answer 17

By the thickness of the top sheet, thin sheets are dimpled and thick sheets may be countersunk

Question 18

What action is taken to prevent cracks from forming while dimpling magnesium or some hard sheet metals?

Answer 18

Hot dimpling equipment is used to preheat and soften the metal before the dimple is formed

Question 19

What type of damage can occur when using a rivet shank that does not properly fit the rivet?

Answer 19

The rivet head and sheet metal may be damaged

Question 20

Why is it important to use the proper bucking bar when performing sheet metal riveting?

Answer 20

A bucking bar too large or heavy is difficult to control and you can damage the sheet metal. A bucking bar too light will not properly upset the rivet before work hardening occurs.

Question 21

What procedures should be followed to properly remove a solid shank rivet?

Answer 21

Center punch the rivet and drill to the base of the rivet head usually the same size or one size smaller then use a pin punch to chip off the river head

Question 22

Which of the five stresses is the most common cause of rivet failure?

Answer 22

Shear