Sheet Metal Structural Repairs 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 Sheet Metal Structural Repairs flashcards as text
When laying out a rivet pattern for a patch repair, the transverse pitch (row spacing) should typically be:
Answer: 0.866 times the longitudinal pitch (for staggered rows)
For staggered rivet rows, transverse pitch is 0.866 times the longitudinal pitch to maintain proper load distribution.
What is 'chem-milling' used for in aircraft sheet metal fabrication?
Answer: Selectively removing material from sheet metal using chemical etching to reduce weight
Chem-milling uses controlled chemical etching to precisely remove material from selected areas to reduce weight while maintaining structural integrity.
A rivet that has been improperly driven and shows a cracked or split tail should be:
Answer: Removed and replaced
A cracked or split rivet tail indicates a faulty installation; the rivet must be drilled out and replaced with a new one.
Which aluminum alloy is most commonly used for aircraft skin panels due to its excellent strength-to-weight ratio and corrosion resistance when alclad?
Answer: 2024-T3
2024-T3 aluminum is the most widely used aircraft skin alloy, offering high strength, good fatigue resistance, and excellent workability when alclad coated.
When using a hand squeezer to set rivets, which type of rivet set should be used to avoid damaging the surrounding sheet surface?
Answer: Either a flat or crowned set depending on rivet head type
Flat sets are used for universal (round) heads and crowned sets for brazier heads; the correct set prevents marring the surrounding sheet.
What is the maximum allowable depth of a gouge or scratch that can remain on aluminum aircraft skin without repair per AC 43.13-1B?
Answer: 25% of the material thickness
Scratches or gouges exceeding 10% of sheet thickness typically require repair; however, AC 43.13-1B allows up to certain limits depending on location—always verify with the SRM.
Fretting corrosion between aluminum skin and a steel fastener is best prevented by:
Answer: Applying a wet-installation sealant or corrosion inhibiting compound
Wet installation with sealant or corrosion inhibiting compound prevents galvanic contact and moisture intrusion between dissimilar metals.