Aircraft Structures Flashcards
7 cards from real Airframe Mechanic Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Aircraft Structures flashcards as text
What is the primary advantage of a composite sandwich structure (face sheets with honeycomb core) over solid aluminum sheet?
Answer: High stiffness-to-weight ratio with excellent bending resistance
Sandwich construction provides exceptional bending stiffness relative to weight by placing strong face sheets far from the neutral axis, separated by a lightweight core.
During a pressurized aircraft's service life, the fuselage skin experiences repeated pressurization cycles. What fatigue mechanism is primarily responsible for eventual skin cracking?
Answer: Low-cycle fatigue from pressurization/depressurization
Each flight cycle applies one pressurization/depressurization event, constituting low-cycle fatigue that drives crack initiation and propagation in fuselage skin.
A wing rib's primary structural function is to:
Answer: Maintain the airfoil shape and transfer loads to the spar
Ribs define and maintain the wing's airfoil cross-section and transfer chordwise aerodynamic loads to the wing spars.
What is the term for an approved repair that deviates from the original design but restores the structure to an equivalent level of airworthiness?
Answer: Alternate means of compliance (AMOC)
An Alternate Means of Compliance (AMOC) is FAA-approved authorization to use a method, standard, or practice different from that prescribed while still meeting airworthiness requirements.
In a multi-spar wing, what is the primary function of the front spar compared to the rear spar?
Answer: The front spar carries most bending loads; the rear spar supports control surfaces and fuel
In most designs the front spar carries the majority of bending and shear from lift, while the rear spar provides attachment for trailing-edge control surfaces and closes the torsion box.
When a riveted lap joint is inspected and found to have 'working' rivets (fretting debris around rivet heads), this indicates:
Answer: The rivets are loose and the joint is transferring load inadequately
Fretting debris (black powder or smearing) around rivet heads is evidence of rivet movement, indicating loose rivets that are no longer properly transferring shear loads.
What type of corrosion preferentially attacks aluminum alloy grain boundaries and causes layers of metal to separate?
Answer: Intergranular corrosion
Intergranular corrosion attacks along grain boundaries in susceptible alloys, eventually causing exfoliation where layers of material separate and flake off.