Afab 110 midterm study guide units 1- 8
Questions With Complete Solutions
Course
Afab 110
Q1. (Unit 1: Safety)
What type of fire extinguisher should be used on an electrical fire in an aircraft maintenance
hangar?
Solution:
Class A: wood/paper
Class B: flammable liquids
Class C: electrical fires
Therefore, a CO₂ or dry chemical extinguisher (Class C) is used.
Q2. (Unit 2: Aircraft Drawings)
An aircraft drawing shows a line type that is long-short-long. What does this represent?
Solution:
Solid line = visible edge
Dashed = hidden edge
Phantom (long-short-long) = alternate position or adjacent part.
Answer: Phantom line indicates alternate position or adjacent component.
Q3. (Unit 3: Materials)
What are the main advantages of using aluminum alloys in aircraft structures?
Solution:
High strength-to-weight ratio
Corrosion resistance (with treatments)
Workability (easy to machine/form)
Availability and cost-effectiveness
Answer: Aluminum alloys provide lightweight strength, corrosion resistance, and
good formability.
,Q4. (Unit 3: Materials)
Which heat treatment process increases the hardness of steel by rapid cooling?
Solution:
Annealing = softens
Normalizing = refines grain
Quenching = rapid cooling → hardens steel
Answer: Quenching increases steel hardness.
Q5. (Unit 4: Measurements)
Convert 3 5/16 inches into decimal inches (accurate to 3 decimal places).
Solution:
5/16 = 0.3125
3 + 0.3125 = 3.3125
Rounded = 3.313 inches
Q6. (Unit 5: Fasteners)
What is the primary difference between AN, MS, and NAS bolts?
Solution:
AN (Air Force–Navy): General aircraft bolts, medium strength.
MS (Military Standard): Standardized replacements, often supersede AN.
NAS (National Aerospace Standard): Precision, high-strength bolts for critical
applications.
Answer: AN = general, MS = standardized replacement, NAS = high-strength
precision bolts.
Q7. (Unit 6: Composites)
Name one advantage and one disadvantage of using composite materials in aircraft.
Solution:
, Advantage: High strength-to-weight, corrosion resistance, fatigue resistance.
Disadvantage: Hard to detect internal damage (delamination), expensive.
Answer: Advantage – lightweight strength; Disadvantage – hidden damage and
higher cost.
Q8. (Unit 7: Fabrication Processes)
What type of rivet should be used when both sides of a structure are accessible?
Solution:
Blind rivet = one side only.
Solid rivet = requires access to both sides.
Answer: Solid rivets are used when both sides are accessible.
Q9. (Unit 8: Inspection)
During inspection, a mechanic finds a crack propagating from a rivet hole. What type of defect is
this, and what is the likely cause?
Solution:
Type: Stress concentration crack (fatigue crack)
Cause: Cyclic loading and poor stress distribution at fastener holes.
Answer: Fatigue crack caused by stress concentration at the rivet hole.
Q10. (Comprehensive, Units 1–8)
A mechanic must replace a corroded aluminum skin panel. List the general steps in order:
1. Remove damaged panel
2. Inspect underlying structure
3. Fabricate replacement panel
4. Apply protective coating
5. Install new panel with correct fasteners
Solution:
Correct order = 1 → 2 → 3 → 4 → 5
Questions With Complete Solutions
Course
Afab 110
Q1. (Unit 1: Safety)
What type of fire extinguisher should be used on an electrical fire in an aircraft maintenance
hangar?
Solution:
Class A: wood/paper
Class B: flammable liquids
Class C: electrical fires
Therefore, a CO₂ or dry chemical extinguisher (Class C) is used.
Q2. (Unit 2: Aircraft Drawings)
An aircraft drawing shows a line type that is long-short-long. What does this represent?
Solution:
Solid line = visible edge
Dashed = hidden edge
Phantom (long-short-long) = alternate position or adjacent part.
Answer: Phantom line indicates alternate position or adjacent component.
Q3. (Unit 3: Materials)
What are the main advantages of using aluminum alloys in aircraft structures?
Solution:
High strength-to-weight ratio
Corrosion resistance (with treatments)
Workability (easy to machine/form)
Availability and cost-effectiveness
Answer: Aluminum alloys provide lightweight strength, corrosion resistance, and
good formability.
,Q4. (Unit 3: Materials)
Which heat treatment process increases the hardness of steel by rapid cooling?
Solution:
Annealing = softens
Normalizing = refines grain
Quenching = rapid cooling → hardens steel
Answer: Quenching increases steel hardness.
Q5. (Unit 4: Measurements)
Convert 3 5/16 inches into decimal inches (accurate to 3 decimal places).
Solution:
5/16 = 0.3125
3 + 0.3125 = 3.3125
Rounded = 3.313 inches
Q6. (Unit 5: Fasteners)
What is the primary difference between AN, MS, and NAS bolts?
Solution:
AN (Air Force–Navy): General aircraft bolts, medium strength.
MS (Military Standard): Standardized replacements, often supersede AN.
NAS (National Aerospace Standard): Precision, high-strength bolts for critical
applications.
Answer: AN = general, MS = standardized replacement, NAS = high-strength
precision bolts.
Q7. (Unit 6: Composites)
Name one advantage and one disadvantage of using composite materials in aircraft.
Solution:
, Advantage: High strength-to-weight, corrosion resistance, fatigue resistance.
Disadvantage: Hard to detect internal damage (delamination), expensive.
Answer: Advantage – lightweight strength; Disadvantage – hidden damage and
higher cost.
Q8. (Unit 7: Fabrication Processes)
What type of rivet should be used when both sides of a structure are accessible?
Solution:
Blind rivet = one side only.
Solid rivet = requires access to both sides.
Answer: Solid rivets are used when both sides are accessible.
Q9. (Unit 8: Inspection)
During inspection, a mechanic finds a crack propagating from a rivet hole. What type of defect is
this, and what is the likely cause?
Solution:
Type: Stress concentration crack (fatigue crack)
Cause: Cyclic loading and poor stress distribution at fastener holes.
Answer: Fatigue crack caused by stress concentration at the rivet hole.
Q10. (Comprehensive, Units 1–8)
A mechanic must replace a corroded aluminum skin panel. List the general steps in order:
1. Remove damaged panel
2. Inspect underlying structure
3. Fabricate replacement panel
4. Apply protective coating
5. Install new panel with correct fasteners
Solution:
Correct order = 1 → 2 → 3 → 4 → 5
