MS29513-226 – Textron Aviation OEM Hydraulic Boss Seal O-Ring
Available now on the Airparts.aero Marketplace.
Overview
The MS29513-226 is a high-performance, preformed O-ring packing that holds a dual certification: it is manufactured to the stringent Military Standard MS29513 and is supplied as a genuine Textron Aviation Original Equipment Manufacturer (OEM) component. Its specific engineering purpose is to create a robust, leak-free seal for straight thread tube fittings in high-pressure hydraulic and lubrication system bosses. The O-ring is fabricated from a high-hardness, 90 durometer Nitrile Butadiene Rubber (NBR) compound, a material specifically chosen for its excellent resistance to petroleum-based fluids and its ability to withstand extrusion under intense pressure.
While the MS29513-226 is a standard for aviation at large, sourcing it as a Textron Aviation OEM part provides an additional layer of assurance. It guarantees that the component is an approved, fully traceable part for installation on Textron's fleet of Cessna and Beechcraft aircraft. For maintainers of these airframes, this O-ring represents the correct, factory-specified component for ensuring the integrity of critical fluid power connections.
Key Features
Dual-Standard Assurance: Meets the rigorous, universal requirements of Military Standard MS29513 and is certified as a Textron Aviation OEM part.
High-Pressure Boss Seal Design: Specifically engineered for static axial sealing of straight thread tube fittings in their corresponding ports (bosses).
90 Durometer NBR Compound: The high-hardness (90 Shore A) Nitrile (Buna-N) elastomer provides superior resistance to high-pressure extrusion, a common failure mode in hydraulic systems.
Petroleum Fluid Compatible: The NBR material offers excellent, long-term resistance to swelling and degradation from petroleum-based hydraulic fluids (e.g., MIL-H-5606), engine oils, and fuels.
AS568 Standard Sizing: Conforms to the AS568-226 dimensional standard for guaranteed fitment with all corresponding aerospace fittings and ports.
OEM Approved: Certified by Textron Aviation for use on their aircraft, ensuring compliance with the airframe's type certificate.
Technical Specifications
Part Number: MS29513-226
Component Type: Preformed O-Ring Packing, Hydraulic Boss Seal
Governing Specification: MS29513
OEM Authority: Textron Aviation
Material: Nitrile Butadiene Rubber (NBR / Buna-N)
Hardness: 90 ± 5 Durometer Shore A
Dimensions (AS568-226):
Inside Diameter (ID): 1.734 inches
Cross-Section (CS): 0.139 inches
Compatible Fluids: Petroleum-based hydraulic fluids, lubricating oils, greases, and fuels.
Typical Temperature Range: -40°F to +250°F (-40°C to +121°C)
Aircraft Compatibility
As a Textron Aviation OEM part, this O-ring is the specified component for numerous applications across their product lines. It is also a standard hardware item used more broadly in aviation.
Primary Textron Aviation Platforms:
Cessna Citation Series (525, 560XL, 680, 750, etc.)
Beechcraft King Air Series (90, 200, 300, 350)
Beechcraft Bonanza / Baron
Cessna Caravan Series
General Aviation Usage: Used across all sectors of aviation employing MS-standard straight thread hydraulic fittings.
Note: Verification of applicability is the responsibility of the installer. Always consult the current version of the aircraft's Illustrated Parts Catalog (IPC) and maintenance manual to confirm part number eligibility.
Applications
Sole Application: Creating a static seal for straight thread tube fittings where they connect to the ports (bosses) of hydraulic system components, including:
Landing gear actuators and brake system manifolds
Hydraulic pumps and power packs
Flight control actuators and valves
Filter housings and reservoirs
Why Choose MS29513-226 from Textron?
Hydraulic system integrity is a flight-critical concern. Choosing this part provides dual confidence. First, it meets the public, verifiable MS29513 standard, guaranteeing its material and physical properties. Second, as a Textron Aviation OEM part, it comes with the manufacturer's direct approval and traceability for their aircraft. This eliminates any ambiguity and ensures you are installing the exact component specified in the IPC, protecting against the use of generic, unapproved seals that could lead to high-pressure leaks, system failure, and significant safety hazards.
The MS29513-226 is engineered for a static axial compression seal, a high-pressure application fundamentally different from a typical radial seal. The O-ring is designed to be installed on the unthreaded shank of a male straight thread tube fitting, where it abuts the thread relief. As the fitting is torqued into a corresponding port (boss), the O-ring is compressed axially between the fitting's shoulder and the precision-machined face or chamfer of the port. The 90 durometer hardness of its Nitrile Butadiene Rubber (NBR) compound is the critical engineering property in this system. This high material modulus provides the necessary resistance to the intense hydraulic pressure that attempts to force the elastomer into the minute clearance of the thread path. A softer, 70 durometer O-ring would lack the requisite shear strength and would fail by extrusion, leading to a catastrophic loss of fluid and pressure.
Note: This component has a finite shelf life defined by standards like ARP5316. The cure date and expiration must be verified prior to installation. It is a single-use part; a new O-ring must be used every time a fitting is reinstalled. The port and fitting sealing surfaces must be impeccably clean and free of scratches or damage. The O-ring must be lubricated with clean system hydraulic fluid before installation.
Documentation
The base standard for this part is publicly available through the Department of Defense ASSIST database, providing the foundational specifications for material, dimension, and quality. OEM-specific documentation is contained within the Textron Aviation maintenance manuals.
ASSIST Document Summary Page for MS29513: http://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=46077
Fits in
- Bombardier Challenger 601
- Bombardier Challenger 604
- Bombardier Challenger 605
- Bombardier Learjet 40
- Bombardier Learjet 45
- Dassault Falcon 2000 all variants
- Dassault Falcon 7X
- Dassault Falcon 900 all variants
- Embraer Legacy 600-650
- Gulfstream G-IV/GIV-SP/G-400/G-450/G-300
- Gulfstream G-V/G-V-SP/G-550/G-500
- Textron Aviation Cessna 560 Citation V-Ultra-Encore-Excel-XLS
- Textron Aviation Cessna 650 Citation III-IV-VI-VII
- Textron Aviation Cessna 680 Citation Sovereign
- Textron Aviation Cessna 750 Citation X