The 424-052 is a Piper OEM cotter pin used as a mechanical locking fastener in aircraft assemblies. It is designed to secure castellated nuts, clevis pins, or other fasteners in place by preventing unintentional loosening under vibration and operational loads.

In Piper aircraft applications, cotter pins like the 424-052 are commonly used throughout airframe structures, landing gear assemblies, flight control linkages, and control cable systems, depending on aircraft model configuration. Its primary function is to act as a simple but critical safety locking device that ensures fasteners remain properly secured during all phases of flight and ground operation.

The cotter pin is installed by inserting it through a drilled hole in a fastener (such as a castellated nut or pin) and then bending the legs apart to mechanically lock it in place. This prevents rotation or backing out of the secured fastener, even under vibration, cyclic loading, or shock conditions.

Manufactured to Piper OEM specifications, the 424-052 is typically made from corrosion-resistant stainless steel or soft carbon steel, allowing for both durability and ease of bending during installation.

Although small and inexpensive, it is a critical safety item, and improper installation or reuse after removal is not permitted in standard aviation maintenance practice.

Key features include:

Piper 424-052 cotter pin (OEM locking fastener)
Secures castellated nuts, bolts, and clevis pins
Prevents loosening under vibration and cyclic loads
Installed by bending legs after insertion
Material: corrosion-resistant stainless steel or carbon steel
Lightweight and simple mechanical locking device
Used in airframe, landing gear, and control systems
Single-use safety hardware (replaced after removal)
Essential for fastener retention and flight safety compliance
Direct replacement part per Piper IPC specifications