Airframe Mechanic Certification Aircraft Structures 2

Question 1

What type of stress acts perpendicular to the cross-section of a structural member and tends to pull it apart?

Accepted Answer

Tension

Answer

Tension is a pulling force that acts perpendicular to the cross-section and tends to elongate or pull a structural member apart.

Question 2

In a semi-monocoque fuselage, which structural members run longitudinally and carry primary bending loads?

Accepted Answer

Stringers

Answer

Stringers run longitudinally along the fuselage and carry primary bending and axial loads in a semi-monocoque structure.

Question 3

What is the primary purpose of a wing's main spar?

Accepted Answer

Carry bending and shear loads from lift

Answer

The main spar is the primary load-carrying member of the wing, designed to resist bending and shear forces generated by lift.

Question 4

Which aluminum alloy series is most commonly used in aircraft primary structure due to its high strength-to-weight ratio?

Accepted Answer

2024 series

Answer

2024-T3 aluminum alloy is widely used in aircraft primary structure because of its excellent strength-to-weight ratio and fatigue resistance.

Question 5

A crack found running parallel to the length of a fuselage stringer is most likely caused by which type of stress?

Accepted Answer

Hoop stress

Answer

Hoop (circumferential) stress from pressurization acts perpendicular to the fuselage axis, causing cracks that run parallel to longitudinal members.

Airframe Mechanic Certification Practice Test