AMT Airframe Structures 3 — Questions and Answers
Question 1: What term describes the gradual reduction in wing thickness and/or chord from root to tip?
- Sweep
- Taper (Correct answer)
- Dihedral
- Washout
Correct answer: Taper
Taper refers to the reduction in wing chord and/or thickness from the root to the tip to improve aerodynamic efficiency.
Question 2: A 100% visual inspection of a welded aircraft steel tube fuselage should include checking for:
- Paint color consistency
- Cracks, dents, and evidence of overheating in the heat-affected zone (Correct answer)
- Antenna mount alignment
- Interior upholstery condition
Correct answer: Cracks, dents, and evidence of overheating in the heat-affected zone
Welded steel tube structures must be inspected for cracks, dents, and heat-affected zone discoloration that may indicate weld failures or structural compromise.
Question 3: What is the correct term for the angle between the wing chord line and the longitudinal axis of the aircraft?
- Angle of attack
- Angle of incidence (Correct answer)
- Dihedral angle
- Sweepback angle
Correct answer: Angle of incidence
The angle of incidence is the fixed angle at which the wing is mounted relative to the aircraft's longitudinal axis.
Question 4: In the damage tolerance design philosophy, what is the primary goal regarding structural cracks?
- Prevent any crack formation in the structure
- Ensure cracks grow slowly enough to be detected before failure (Correct answer)
- Eliminate all stress concentrations
- Use only composite materials to avoid cracks
Correct answer: Ensure cracks grow slowly enough to be detected before failure
Damage tolerance design ensures that if cracks form, they propagate slowly enough to be found during scheduled inspections before causing catastrophic failure.
Question 5: What is the primary structural function of a honeycomb core in a sandwich composite panel?
- Carry primary tensile loads
- Provide shear rigidity and separate the face sheets (Correct answer)
- Act as a moisture barrier
- Conduct electrical current for lightning protection
Correct answer: Provide shear rigidity and separate the face sheets
The honeycomb core resists shear forces and maintains separation between the face sheets, greatly increasing panel stiffness with minimal weight.
Question 6: Which rivet material is typically used to join magnesium alloy aircraft structures?
- 2117-T4 aluminum alloy
- 5056 aluminum alloy (Correct answer)
- Stainless steel
- Monel
Correct answer: 5056 aluminum alloy
5056 aluminum alloy rivets are used with magnesium structures because their galvanic potential is closest to magnesium, minimizing corrosion.
Question 7: What does the term "fail-safe" mean in aircraft structural design?
- The structure never fails under any load
- Multiple load paths exist so failure of one member does not cause total structural failure (Correct answer)
- All fasteners are safety-wired
- The structure is inspected after every flight
Correct answer: Multiple load paths exist so failure of one member does not cause total structural failure
Fail-safe design provides redundant load paths so that if one structural element fails, adjacent members can carry the load without catastrophic collapse.
AMT Airframe Structures 3
What term describes the gradual reduction in wing thickness and/or chord from root to tip?