FREE Airframe Mechanic Sheet Metal Structures Questions and Answers

Question 1

When fabricating a 90-degree bend in a piece of aluminum sheet metal with a radius of 0.125 inches and a thickness of 0.063 inches, what is the setback?

Accepted Answer

0.188 inches

Answer

For a 90-degree bend, the setback is calculated by adding the bend radius to the thickness of the material. In this case, Setback = Radius + Thickness = 0.125" + 0.063" = 0.188". Setback is a critical calculation for determining the starting point of the bend.

Question 2

An aircraft's aluminum skin shows signs of fine, worm-like lines of corrosion products beneath the paint film, particularly in a high-humidity environment. Which type of corrosion is most likely present?

Accepted Answer

Filiform corrosion

Answer

Filiform corrosion is characterized by its worm-like appearance as it forms tunnels of corrosion products under the paint. It is common on painted aluminum surfaces that are exposed to high humidity.

Question 3

During a repair of a stressed-skin structure, a small crack is found. What is the first procedural step to stop the progression of the crack before applying a patch?

Accepted Answer

Drill a small hole at each end of the crack.

Answer

To prevent a crack from spreading in a stressed-skin structure, a small hole must be drilled at each end of the crack. This technique, known as stop-drilling, relieves the stress concentration at the crack tips.

Question 4

What does the 'AD' in the rivet identification code AN470AD4-5 signify?

Accepted Answer

The material is 2117-T aluminum alloy.

Answer

In the standard rivet identification system, the letter code following the head style indicates the rivet's material composition. 'AD' specifies that the rivet is made from 2117-T aluminum alloy.

Question 5

A technician is performing a flush patch repair on a pressurized fuselage skin. How should the thickness of the doubler and the filler (patch) relate to the original skin thickness?

Accepted Answer

The doubler should be one gauge thicker, and the filler should be the same thickness as the original skin.

Answer

For a flush patch repair, the filler plug must be of the same gauge and material as the original skin to maintain a smooth surface. The doubler, which provides the structural reinforcement from the inside, should be made of material one gauge heavier (thicker) than the original skin.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

FREE Airframe Mechanic Sheet Metal Structures Questions and Answers