The S-0309-011 is an aircraft-grade O-ring used as a sealing element in aviation fluid systems such as fuel, hydraulic, oil, or pneumatic assemblies, depending on the installation point in the aircraft Illustrated Parts Catalog (IPC). It is part of the S-0309 sealing series, where each suffix defines a specific diameter and cross-section for a controlled sealing application.

This O-ring is typically made from fluorocarbon (FKM / Viton-type) elastomer, giving it strong resistance to aviation fuels, oils, hydraulic fluids, and temperature extremes. It is used in static sealing applications where pressure integrity and leak prevention are critical.

Key features include:

Aircraft-grade elastomer sealing O-ring
S-0309 series aviation-specific part number
Used in fuel, oil, hydraulic, or pneumatic system sealing (application-dependent)
Typically fluorocarbon (FKM / Viton-type) material
High resistance to fuel, oil, and temperature cycling
Designed for static sealing in machined grooves
Must match exact IPC dimensions (not interchangeable without cross-reference)
Used in certified aircraft maintenance and overhaul procedures
Critical for leak-free operation of pressurized systems
Controlled consumable aviation hardware component