Airframe Mechanic Certification Sheet Metal Structural Repairs 2

Question 1

When performing a sheet metal repair, the minimum edge distance for a rivet from the edge of the sheet is typically:

Accepted Answer

1.5 times the rivet diameter

Answer

Minimum edge distance is 1.5 times the rivet diameter to prevent sheet splitting or edge tearout.

Question 2

Which type of corrosion appears as a white or gray powdery deposit on aluminum aircraft skin?

Accepted Answer

Surface oxidation (white corrosion)

Answer

White or gray powdery deposits on aluminum are characteristic of surface oxidation, the most common and easily treated form of aluminum corrosion.

Question 3

A 'stop-drill' is used in sheet metal repair to:

Accepted Answer

Halt crack propagation by removing the stress concentration at the crack tip

Answer

Stop-drilling places a hole at the end of a crack to redistribute stress and prevent the crack from continuing to grow.

Question 4

What is the purpose of using a dimpling operation in sheet metal work?

Accepted Answer

To create a countersunk recess in thin sheets that cannot be machine countersunk

Answer

Dimpling forms a countersunk recess in sheet metal that is too thin to machine countersink, allowing flush rivet installation.

Question 5

When sizing a rivet for a sheet metal repair, the correct rivet diameter should be:

Accepted Answer

3 times the thickness of the thickest sheet

Answer

Rivet diameter should be approximately 3 times the thickness of the thickest sheet being joined for optimal strength.

Airframe Mechanic Certification Practice Test