S9413-214 – Textron Aviation OEM Preformed Packing (O-Ring)
Available now through the AirParts Aero marketplace.
Overview Section
The Textron Aviation S9413-214 is a high-specification Preformed Packing (O-Ring) designed for use in critical fluid systems across the Textron family of aircraft, including Cessna, Beechcraft, and Hawker. This O-ring is engineered to provide a robust, leak-proof seal in both static and dynamic applications.
The S9413 series is a proprietary Textron specification that defines strict metallurgical and elastomeric requirements, often exceeding standard industrial or military grades. The -214 dash size corresponds to a specific set of dimensions (Inside Diameter and Cross-Section) designed to fit perfectly into aerospace-standard glands. This O-ring is typically utilized in systems where resistance to high-pressure hydraulic fluids, engine lubricants, or environmental extremes is mandatory.
Key Features Section
Aerospace Grade Elastomer: Manufactured from advanced synthetic rubber (typically Nitrile or Fluorocarbon, depending on the specific system callout) designed for long-term stability in aviation environments.
Precision Geometry: Produced to exact tolerances to ensure a controlled "squeeze" when installed, preventing both fluid bypass and excessive friction.
Compatibility with Aviation Fluids: Engineered to resist degradation when exposed to MIL-PRF-5606 (red oil), MIL-PRF-83282, or turbine lubricants.
Wide Operating Temperature Range: Capable of maintaining flexibility in sub-zero high-altitude conditions and structural integrity in high-heat engine compartments.
Standardized Sizing: The -214 designation ensures compatibility with standard AS568-style glands, facilitating easy identification and replacement during scheduled maintenance.
Textron OEM Quality: Meets the original engineering standards for Cessna and Beechcraft airframes, ensuring continued airworthiness and compliance with Type Certificate Data Sheets (TCDS).
Technical Specifications Section
| Specification | Detail |
| Part Number | S9413-214 |
| Manufacturer | Textron Aviation (Cessna/Beechcraft) |
| Component Type | Preformed Packing / O-Ring |
| Dash Size | -214 |
| Inside Diameter (ID) | 0.984 in (24.99 mm) nominal |
| Cross-Section (W) | 0.139 in (3.53 mm) nominal |
| Material | System-dependent (Consult Illustrated Parts Catalog) |
| Standard | Textron S9413 proprietary spec |
Aircraft Compatibility Section
The S9413-214 is found in numerous locations throughout the Textron fleet:
Beechcraft King Air (90, 200, 300, 350): Often utilized in landing gear actuators, brake system components, and hydraulic power packs.
Cessna Citation Series (525, 560, 680, 750): Found in environmental control systems (ECS), hydraulic manifolds, and fuel system unions.
Beechcraft Baron / Bonanza: Used in specialized fluid fittings and engine accessory drive interfaces.
Hawker 800/900XP: Critical for various secondary hydraulic systems and flight control actuators.
Technical Applications & Safety
O-rings like the S9413-214 function by creating a physical barrier within a "gland" or groove.1 Under pressure, the elastomer deforms slightly to block the leak path.
Safety Warning: Never substitute an S9413-spec O-ring with a hardware-grade equivalent. Aerospace packings are tested for "Compression Set"—the ability to return to their original shape. A hardware-grade O-ring may flatten permanently over time, leading to sudden fluid loss in pressurized systems.2 Additionally, always verify the Cure Date (shelf life) on the packaging. An expired O-ring may feel pliable but can fail under the high-frequency vibration and pressure spikes common in flight.
Maintenance Insight
The value of the S9413-214 lies in its Surface Quality. Textron's S9413 standard requires a high degree of finish, meaning the O-ring is free of mold "flash" or parting lines that could act as a microscopic leak path. This is especially critical in systems using thin-viscosity hydraulic fluids, where even a tiny surface defect can lead to chronic "weeping" at the fitting.
Installation & Maintenance Addendum
Gland Cleanliness: Before installing the new S9413-214, use a lint-free cloth to clean the groove. Even a single strand of hair or a grain of dust can cause a high-pressure leak.
Lubrication: Apply a light coating of the system's operational fluid (e.g., AeroShell Fluid 41) to the O-ring before installation. This prevents the rubber from "scuffing" or "rolling" as the parts are joined.
Inspection: Use a 10x magnifying glass to inspect the O-ring for nicks or cuts before installation. If the O-ring was stretched over threads during assembly, re-inspect it to ensure the threads didn't "slice" the elastomer.