Airframe Mechanic Certification Aircraft Structures & Materials 2 — Questions and Answers
Question 1: Which type of aluminum alloy is most commonly used in aircraft skin due to its high strength-to-weight ratio?
- 1100 series
- 2024-T3 (Correct answer)
- 3003 series
- 5052 series
Correct answer: 2024-T3
2024-T3 aluminum alloy is the most widely used aircraft skin material because of its excellent strength-to-weight ratio and fatigue resistance.
Question 2: What is the primary purpose of a wing spar in an aircraft structure?
- To provide aerodynamic shape to the wing
- To carry the bending loads along the wing span (Correct answer)
- To attach the wing skin to the fuselage
- To house the fuel tanks
Correct answer: To carry the bending loads along the wing span
Wing spars are the primary structural members that carry bending and shear loads along the span of the wing.
Question 3: What does the term 'monocoque' mean in aircraft structural design?
- A structure with no internal framework where the skin carries all loads (Correct answer)
- A structure with both skin and internal framework sharing loads
- A structure using only composite materials
- A structure with a single main spar
Correct answer: A structure with no internal framework where the skin carries all loads
Monocoque construction relies entirely on the external skin to carry structural loads, with no internal framework.
Question 4: Which non-destructive testing method uses high-frequency sound waves to detect internal defects in metal?
- Magnetic particle inspection
- Dye penetrant inspection
- Ultrasonic inspection (Correct answer)
- Eddy current inspection
Correct answer: Ultrasonic inspection
Ultrasonic inspection uses high-frequency sound waves that reflect off internal discontinuities to detect flaws within materials.
Question 5: What is the function of a stringer in fuselage construction?
- To provide circumferential strength to the fuselage
- To carry longitudinal tension and compression loads (Correct answer)
- To act as the primary attachment point for landing gear
- To seal the pressurized cabin
Correct answer: To carry longitudinal tension and compression loads
Stringers run longitudinally along the fuselage and carry axial (tension and compression) loads while stabilizing the skin against buckling.
Question 6: What type of stress is experienced by a rivet when it holds two overlapping sheets being pulled apart?
- Tensile stress
- Compressive stress
- Shear stress (Correct answer)
- Torsional stress
Correct answer: Shear stress
When two overlapping sheets are pulled apart, the rivet experiences shear stress because the force acts across (perpendicular to) its cross-section.
Question 7: Which material property describes a metal's ability to be drawn into wire without breaking?
- Malleability
- Ductility (Correct answer)
- Elasticity
- Brittleness
Correct answer: Ductility
Ductility is the ability of a material to deform plastically under tensile stress, allowing it to be drawn into wire.
