AMT Aircraft Structures and Materials 3 — Questions and Answers
Question 1: What is the function of a web in an aircraft wing spar?
- To provide aerodynamic lift
- To carry shear loads between the spar caps (Correct answer)
- To attach the skin panels to the rib
- To seal fuel inside the wing box
Correct answer: To carry shear loads between the spar caps
The spar web primarily carries vertical shear loads, transferring them between the upper and lower spar caps.
Question 2: When inspecting a composite structure for delamination, which non-destructive testing method is most effective?
- Magnetic particle inspection
- Dye penetrant inspection
- Ultrasonic C-scan inspection (Correct answer)
- Eddy current inspection
Correct answer: Ultrasonic C-scan inspection
Ultrasonic C-scan inspection is the most effective NDT method for detecting internal delamination in composite laminates.
Question 3: What type of corrosion forms between two dissimilar metals in contact with an electrolyte?
- Intergranular corrosion
- Galvanic corrosion (Correct answer)
- Stress corrosion
- Fretting corrosion
Correct answer: Galvanic corrosion
Galvanic corrosion occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte, causing the anodic metal to corrode.
Question 4: Which alloy designation series indicates aluminum alloyed primarily with zinc?
- 2000 series
- 5000 series
- 6000 series
- 7000 series (Correct answer)
Correct answer: 7000 series
The 7000 series aluminum alloys use zinc as the primary alloying element, producing the highest-strength aluminum alloys.
Question 5: What is the primary advantage of a geodesic (geodetic) airframe construction?
- Simplicity of manufacture
- High strength-to-weight ratio with redundant load paths (Correct answer)
- Ease of inspection and repair
- Lower material cost
Correct answer: High strength-to-weight ratio with redundant load paths
Geodesic construction uses interlocking diagonal members that create a very high strength-to-weight ratio with multiple redundant load paths.
Question 6: What is the minimum bend radius rule used to prevent when working sheet metal?
- Springback after bending
- Work hardening at the bend
- Cracking or fracturing of the metal (Correct answer)
- Galvanic corrosion at the bend line
Correct answer: Cracking or fracturing of the metal
Observing minimum bend radius prevents cracking or fracturing of the metal on the outer surface of the bend.
Question 7: In aircraft structural terminology, what is a 'joggle'?
- A type of quick-release fastener
- A small offset in a structural member allowing parts to overlap flush (Correct answer)
- A reinforcement at a bulkhead cutout
- A method of welding thin sheet metal
Correct answer: A small offset in a structural member allowing parts to overlap flush
A joggle is a small step or offset formed into a structural member so that overlapping parts lie flush with each other.
AMT Aircraft Structures and Materials 3
What is the function of a web in an aircraft wing spar?