83978-1216 Legacy Aerospace Nut for Sikorsky Helicopters
Available now on the Airparts.aero Marketplace.
Overview
The 83978-1216 is a genuine OEM-traceable, proprietary nut engineered for flight-critical applications within specific Sikorsky helicopter airframes. This is not a standard AN/MS/NAS nut; it is a custom-manufactured fastener whose specific material composition, thread geometry, and performance characteristics are dictated by Sikorsky engineering drawings. As a proprietary component, it is designed to meet unique stress, vibration, and environmental challenges found in its specific location on the aircraft. Supplied by trusted aerospace distributors like Legacy Aerospace, this nut guarantees full traceability and conformance to the original manufacturer's stringent quality requirements.
Key Features
- Proprietary Engineering Design: A custom-designed fastener engineered by the Original Equipment Manufacturer (OEM) for a specific, high-stress application where standard hardware is insufficient.
- Full Traceability: Supplied with complete traceability documentation back to the OEM-approved source, guaranteeing its authenticity and airworthiness. This is a mandatory requirement for flight-critical hardware.
- Application-Specific Material: Fabricated from a high-strength, aerospace-grade alloy selected by the OEM for its specific combination of tensile strength, fatigue life, and corrosion resistance required for its intended environment.
- Precision Manufacturing: Produced and inspected under rigorous quality control protocols to ensure every dimension, from thread pitch diameter to bearing surface flatness, meets the precise specifications of the engineering drawing.
- Flight-Critical Component: Designed for use in primary structural or system assemblies where its performance is essential to the safety of flight.
Technical Specifications
- Part Number: 83978-1216
- Component Type: Proprietary Aerospace Nut
- Primary OEM: Sikorsky Aircraft
- Material: Aerospace-Grade Alloy Steel or CRES (exact specification is proprietary)
- Finish: Corrosion-Resistant Plating (proprietary)
- Thread Specification: (Proprietary) - Must be verified against the mating bolt and maintenance manual.
- Locking Feature: May be self-locking or used with a secondary locking device (e.g., cotter pin), as specified by the installation manual.
- Certification: Supplied with Certificate of Conformance and full traceability to the OEM.
Aircraft Compatibility
The 83978-1216 nut is a specialized component for specific applications on Sikorsky helicopters. Its use is mandatory as per the manufacturer's documentation and is not interchangeable with standard hardware.
- Primary Aircraft Platform (Example):
- Sikorsky S-76
- May be used on other Sikorsky models such as the UH-60 Black Hawk and its derivatives.
- Specific Application: Used in primary structural joints, flight control systems, or dynamic components like rotor head or transmission assemblies. Verification against the aircraft's Illustrated Parts Catalog (IPC) is essential.
Applications
This proprietary nut is reserved for the most demanding and critical fastening jobs on the airframe:
- Primary Structure & Dynamic Systems: Securing components subjected to extreme vibration, high tensile loads, and severe fatigue cycles.
- Flight Control Systems: Fastening critical linkages and components within the flight control system where fastener integrity is paramount.
- Mandatory Replacement: Must be installed, torqued, and replaced in strict accordance with the procedures and life limits outlined in the aircraft's maintenance manual.
Why Choose 83978-1216?
In the world of rotary-wing aviation, the forces acting on the airframe are immense and complex. Proprietary hardware like the 83978-1216 is engineered to handle these specific, calculated loads. Using a genuine, traceable part is the only way to ensure you are installing a fastener that meets the exact strength, fatigue life, and material requirements of the original design. Substituting with a non-approved or standard part introduces an unacceptable risk that could lead to catastrophic failure. For components this critical, absolute adherence to the OEM specification is the only safe choice.
Order Your 83978-1216 Nuts Now
Ensure the safety and airworthiness of your aircraft with genuine, fully traceable OEM hardware. Visit Airparts.aero to order your 83978-1216 proprietary nuts today.
Proprietary fasteners like the 83978-1216 are born from specific engineering challenges that cannot be met by off-the-shelf standard hardware. The design may incorporate unique features such as a non-standard thread pitch to optimize for vibration resistance, a specific bearing surface angle to match a custom mating surface, or a unique material alloy and heat treatment process to achieve a required strength-to-weight ratio. Because these parts are not governed by a universal MS/AN/NAS standard, the only controlling document is the OEM's engineering drawing. Therefore, full traceability to the OEM is not just a matter of paperwork; it is the only assurance that the part conforms to this unique and flight-critical design.
Note: This is a flight-critical structural component, often with a specific life limit and mandatory replacement schedule. It must only be used in the application specified by the aircraft manufacturer's maintenance and parts manuals. Installation requires the use of a calibrated torque wrench and adherence to all procedures, which may include specific lubrication requirements or multi-stage torquing sequences.
