FAA Aviation Mechanic Airframe (AMA)Airframe StructuresEasy
A technician needs to install a removable inspection panel that mechanics will open frequently during routine maintenance using only a screwdriver, without the panel requiring separate nuts. Which fastener is best suited for this application?
- AHi-Lok fastener
- BAN3 bolt with castellated nut
- CBlind rivet
- DDzus (quarter-turn) fastener
Show answer & explanationAnswer & explanation
Correct answer: D. Dzus (quarter-turn) fastener
Dzus (or Camloc) quarter-turn fasteners allow quick removal and installation of access panels with a simple quarter-turn of a screwdriver, and the receptacle stays attached to the structure, making them ideal for frequently opened panels.
Why the other options are wrong
- A. Hi-Lok fasteners are permanent structural fasteners, not intended for repeated removal.
- B. A castellated nut and bolt requires a wrench and cotter pin, unsuitable for frequent quick access.
- C. Blind rivets are permanent fasteners and cannot be removed without drilling.
Quarter-Turn (Dzus/Camloc) Fastener
A spring-loaded fastener that locks with a 90-degree turn of a screwdriver, used for quick removal and installation of access panels and cowlings.
- Quarter-turn engagement/disengagement
- Receptacle remains attached to structure
- Ideal for frequently accessed panels
Memory trick: Dzus = 'do it in a quarter-second' turn to open