AMT Airframe Systems & Components 3 — Questions and Answers
Question 1: In a pressurized aircraft fuselage, the structure must be designed to withstand which primary stress?
- Compressive hoop stress
- Tensile hoop stress (Correct answer)
- Torsional shear stress
- Bending moment stress
Correct answer: Tensile hoop stress
Internal pressurization creates tensile hoop stress that attempts to expand the fuselage diameter, requiring the skin to resist being pulled apart.
Question 2: What is the purpose of a bleed air system on a turbine-powered aircraft?
- To vent excess hydraulic pressure overboard
- To supply hot compressed air from the engine for cabin pressurization and anti-ice (Correct answer)
- To pre-cool engine oil before it enters the oil cooler
- To provide boundary layer control over wing surfaces
Correct answer: To supply hot compressed air from the engine for cabin pressurization and anti-ice
Bleed air is extracted from engine compressor stages and used for cabin pressurization, air conditioning, anti-icing, and pneumatic systems.
Question 3: Which rivet is most appropriate for use in areas that are accessible from one side only?
- AN470 universal head rivet
- Cherry (blind) rivet (Correct answer)
- AN426 countersunk rivet
- Brazier head rivet
Correct answer: Cherry (blind) rivet
Blind rivets, such as Cherry rivets, are designed to be installed from one side when the back side is inaccessible.
Question 4: A semi-monocoque fuselage structure derives most of its strength from:
- The internal framework of bulkheads and stringers only
- A combination of skin, stringers, frames, and bulkheads working together (Correct answer)
- A thick external skin acting alone
- Heavy longerons running the full fuselage length
Correct answer: A combination of skin, stringers, frames, and bulkheads working together
Semi-monocoque construction shares loads between the stressed skin and the internal framework of stringers, frames, and bulkheads.
Question 5: What does a negative dihedral (anhedral) wing configuration primarily provide?
- Increased lateral stability
- Decreased lateral stability for improved maneuverability (Correct answer)
- Greater ground clearance for engines
- Reduced induced drag
Correct answer: Decreased lateral stability for improved maneuverability
Anhedral reduces the natural lateral stability (dihedral effect), which is desirable in highly maneuverable or swept-wing high-speed aircraft.
Question 6: When must a Required Inspection Item (RII) on an air carrier aircraft be re-inspected?
- After any flight where turbulence was encountered
- When the item was not inspected by an authorized inspector or was found defective and repaired (Correct answer)
- Every 100 hours regardless of status
- Only when the original inspector is unavailable
Correct answer: When the item was not inspected by an authorized inspector or was found defective and repaired
An RII must be reinspected if it was not properly inspected by an authorized RII inspector or if it was found defective and subsequently repaired.
Question 7: What is the purpose of a bonding jumper on an aircraft fuel system component?
- To prevent fuel from freezing in cold temperatures
- To provide an electrical ground path that prevents static charge buildup (Correct answer)
- To mechanically secure fuel lines against vibration
- To equalize fuel pressure between tanks
Correct answer: To provide an electrical ground path that prevents static charge buildup
Bonding jumpers provide a continuous electrical path to dissipate static electricity, preventing sparks that could ignite fuel vapors.
AMT Airframe Systems & Components 3
In a pressurized aircraft fuselage, the structure must be designed to withstand which primary stress?