FAA Aviation Mechanic Airframe (AMA)Airframe StructuresMedium
A technician is safety-wiring a turnbuckle on a flight control cable assembly using two separate lengths of wire, with each wire independently wrapped a minimum of three turns around the barrel and through its adjacent cable eye. Which turnbuckle safetying method is being used?
- AClip-locking method
- BLock-wire pigtail method
- CDouble-wrap method
- DSingle-wrap method
Show answer & explanationAnswer & explanation
Correct answer: C. Double-wrap method
The double-wrap method uses two separate pieces of safety wire, each independently wrapped a minimum of three turns through the barrel and cable eye holes, providing redundancy in case one wire fails. The single-wrap method uses one continuous wire with a minimum of four wraps.
Why the other options are wrong
- A. The clip-locking method uses mechanical locking clips instead of safety wire entirely.
- B. There is no standard turnbuckle safetying method called the 'lock-wire pigtail method'.
- D. The single-wrap method uses one continuous wire with at least four wraps, not two separate wires.
Turnbuckle Safetying Methods
Approved methods (single-wrap, double-wrap, or clip-locking) used to prevent a turnbuckle barrel from rotating and loosening a control cable after rigging.
- Single-wrap: one wire, minimum 4 wraps
- Double-wrap: two wires, minimum 3 wraps each
- Clip-locking: mechanical spring clips, no wire needed
Memory trick: Double-wrap = Double the wires, Double the safety.