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D38999/24WF35SN – TE Connectivity Circular MIL Spec Connector 66 Pin Size 19 Jam Nut Receptacle
Available now on the Airparts.aero Marketplace.
The D38999/24WF35SN is a high-density, flight-critical circular electrical connector engineered for the most rigorous aerospace and defense applications. As a MIL-DTL-38999 Series III Jam Nut Receptacle (Style 24), this component is designed for bulkhead or panel mounting where space is at a premium and a superior environmental seal is required. Utilizing a Size 19 shell with the high-density "35" insert arrangement, it supports 66 Size 22D socket contacts, facilitating the complex signal and data requirements of modern digital avionics and flight control systems.
This connector features the Series III triple-start threaded coupling mechanism, which provides a rapid, secure connection with a built-in anti-decoupling ratchet. This design ensures that the electrical interface remains stable even under the extreme vibration profiles found in jet engine nacelles and high-performance airframes. The "W" class finish indicates a robust Olive Drab Cadmium plating over a high-strength aluminum alloy shell, providing 500 hours of salt spray protection and excellent shell-to-shell conductivity for EMI/RFI shielding.
The D38999/24WF35SN is a cornerstone of reliable aircraft wiring. Its rear-release contact system and advanced fluorosilicone sealing prevent moisture "wicking" and fluid ingress, maintaining dielectric stability in both pressurized and unpressurized zones. For the professional A&P/IA or avionics engineer, this connector represents a mission-ready solution that meets or exceeds all NAVAIR and MIL-SPEC performance standards.
Key Features
Self-Locking Triple-Start Thread: Engineered to prevent decoupling under high-amplitude vibration without the need for safety wire.
Superior EMI/RFI Shielding: Integrated grounding fingers and cadmium plating provide high-frequency shielding effectiveness of 65dB at 10 GHz.
66-Pin High-Density Configuration: Maximizes I/O capacity in a compact Size 19 envelope using Size 22D socket contacts.
Jam Nut Mounting (Style 24): Features a single-hole mounting design with a peripheral O-ring seal, optimized for bulkhead penetrations.
Environmental Sealing: Equipped with a multi-tier fluorosilicone grommet and interfacial seal to protect against Skydrol, jet fuels, and de-icing fluids.
Technical Specifications
Part Number: D38999/24WF35SN
Component Type: Circular MIL-DTL-38999 Series III Receptacle
Manufacturer: TE Connectivity / DEUTSCH
Shell Size: 19
Insert Arrangement: 19-35 (66 Contacts)
Contact Type: Socket (S), Crimp Rear-Release
Contact Size: 22D
Polarization: Normal (N)
Material: Aluminum Alloy Shell
Finish: Olive Drab Cadmium over Electroless Nickel
Dielectric Withstanding Voltage: 1300 VAC (Sea Level)
Temperature Range: $-65^{\circ}\text{C}$ to $+175^{\circ}\text{C}$
Salt Spray Rating: 500 Hours
Vibration: Sine 60g / Random 44g
Governing Specification: MIL-DTL-38999 Series III
Aircraft Compatibility
Commercial Transport: Boeing 737 MAX, 777X, 787 Dreamliner, Airbus A321neo, A350.
Military Platforms: F-18 Super Hornet, F-22 Raptor, C-17 Globemaster III.
Business Aviation: Bombardier Global 7500, Dassault Falcon 8X, Gulfstream G700.
Note: The Illustrated Parts Catalog (IPC) for the specific tail number must be consulted for final configuration and effectivity verification.
Applications
Data Bus Integration: Primary interface for MIL-STD-1553 and ARINC 429 data streams.
Cockpit Bulkhead Penetration: Maintaining pressure vessel integrity while routing dense avionics harnesses.
FADEC Systems: Critical signal routing for Full Authority Digital Engine Control units.
Why Choose D38999/24WF35SN?
Choosing a genuine MIL-SPEC D38999/24WF35SN is vital for maintaining the airworthiness and safety of flight-critical systems. Generic or industrial-grade connectors often lack the "scoop-proof" design and specialized plating required to prevent pin damage during blind mating or galvanic corrosion in maritime environments. By utilizing TE Connectivity’s aerospace-grade hardware, operators ensure that signal attenuation and intermittent faults are eliminated at the source.
The D38999/24WF35SN is a pinnacle of interconnect engineering, specifically designed to mitigate the risks associated with electromagnetic interference (EMI) and high-frequency cross-talk in dense wiring environments. The Size 19-35 insert arrangement is a non-symmetric layout that maximizes contact density while maintaining the required dielectric separation to prevent corona discharge at high altitudes. The jam nut design (Style 24) is preferred for its ability to provide a consistent peripheral seal against the bulkhead through the compression of a high-durometer O-ring. The shell’s aluminum construction is treated with a sacrificial cadmium coating over an electroless nickel strike; this provides a low-resistance path for EMC grounding while ensuring the base metal is protected from the anisotropic nature of corrosion in saline environments. The triple-start thread utilizes a constant-torque ratcheting mechanism to ensure that the connector remains seated even when subjected to harmonic resonance and thermal expansion/contraction cycles.
Note: The D38999/24WF35SN is a flight-critical electrical component. Installation must be performed by a certified A&P/Avionics technician. It is essential to use the correct M22520/2-01 crimper with the appropriate positioner and M81969/14-01 insertion/extraction tools to ensure the integrity of the contact retention clips. Torque the jam nut to the specific values found in the Aircraft Maintenance Manual (AMM) to avoid over-compression of the environmental seal.
