A&P - Aircraft and Powerplant Sheet Metal Structural Repair Questions and Answers

Question 1

When performing a sheet metal repair on an aircraft, what is the generally accepted minimum edge distance for a single row of protruding head rivets?

Accepted Answer

Two times the rivet shank diameter

Answer

One and a half times the rivet shank diameter

Answer

Three times the rivet shank diameter

Answer

The thickness of the sheet being riveted

Question 2

A technician discovers a 1.5-inch long crack in a non-structural aluminum alloy skin panel. Which of the following is the correct initial step to repair the crack?

Accepted Answer

Stop-drill the ends of the crack.

Answer

Weld the crack from end to end.

Answer

Immediately install a doubler patch over the crack.

Answer

Apply a bead of structural adhesive along the crack.

Question 3

In a sheet metal lap joint repair, the rivet pitch (the distance between the centers of adjacent rivets in the same row) should generally be no less than:

Accepted Answer

Three times the rivet diameter.

Answer

Two times the rivet diameter.

Answer

The thickness of the thickest sheet.

Answer

Four times the rivet diameter.

Question 4

When fabricating a replacement part that requires a 90-degree bend, the term 'bend allowance' refers to:

Accepted Answer

The length of the curved portion of the metal within the bend.

Answer

The extra material added to the flange for trimming.

Answer

The total length of the part before bending.

Answer

The amount the material will spring back after being bent.

Question 5

A repair is being made to a section of 0.040-inch 2024-T3 aluminum skin using a doubler patch of the same material and thickness. According to common practice, what is the most appropriate solid shank rivet diameter to use for this repair?

Accepted Answer

1/8 inch (0.125")

Answer

3/32 inch (0.09375")

Answer

5/32 inch (0.15625")

Answer

3/16 inch (0.1875")

Question 6

Which of the following is a primary objective when designing a sheet metal structural repair for an aircraft?

Accepted Answer

To restore the original strength and stiffness of the structure while minimizing weight.

Answer

To make the repair section significantly stronger than the original structure.

Answer

To use the thickest gauge material available for maximum durability.

Answer

To complete the repair using only blind rivets for speed and convenience.