70400-00511-043 – Sikorsky Helicopter OEM Tail Cone Wire Rope Assembly
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Overview Section
The Sikorsky Helicopter 70400-00511-043 is a flight-critical Original Equipment Manufacturer (OEM) Tail Cone Wire Rope Assembly designed specifically for use in the dynamic rotorcraft environment. This assembly, often referred to as a Control Cable or Flexible Control Cable, serves to transmit pilot input forces from the primary flight control system located within the main fuselage, through the length of the tail cone, to the tail rotor pitch change mechanism or another flight surface actuator (such as a horizontal stabilizer). As a primary flight control component, its integrity is essential for maintaining directional control of the aircraft, particularly in compensation for main rotor torque.
The assembly is constructed from high-strength, corrosion-resistant Corrosion-Resistant Steel (CRES) strands (often Type 304 or 305 stainless steel) formed into a multi-strand cable configuration (typically 7 times 19 or 7 times 7), providing the necessary flexibility and exceptional tensile strength. The wire rope is precisely manufactured to a specific length and tension tolerance, and is supplied with factory-swaged end fittings (terminals) that attach to the bellcranks or tension regulators within the airframe. The -043 suffix in the part number indicates a specific length or terminal configuration unique to certain models or tail cone variants.
Key Features Section
Primary Flight Control Component: Transmits pilot forces for tail rotor pitch control or other critical flight stabilization surfaces.
High-Strength CRES Construction: Fabricated from multiple strands of high-tensile strength Corrosion-Resistant Steel (CRES), ensuring maximum fatigue life and resistance to atmospheric corrosion.
Precision Swaged End Terminals: Features factory-installed, certified end fittings (terminals) that provide a high-integrity connection point, meeting required pull-out strength specifications (e.g., MIL-DTL-83420).
Specific Length and Tolerance: Manufactured to an exact OEM length specification, minimizing adjustment required during installation and ensuring correct tensioning of the control system.
Low Stretch/High Modulus: Designed to exhibit minimal elastic deformation under maximum operating loads, providing predictable and accurate control response.
Life-Limited Component: Subject to mandatory replacement based on accumulated flight hours or calendar time, as defined in the applicable Component Overhaul Manual (CMM).
Technical Specifications Section
Part Number: 70400-00511-043
Component Type: Tail Cone Wire Rope Control Assembly
OEM Manufacturer: Sikorsky Helicopter (or authorized supplier)
Material: Corrosion-Resistant Steel (CRES), likely Type 304 or 305 Stainless Steel
Construction: Multi-strand wire rope (e.g., 7 times 19 for maximum flexibility and fatigue resistance)
Diameter (Nominal): Must be confirmed with CMM (typically 3/32 to $1/4 inch)
Length: Specific to the -043 variant (Exact dimension must be verified via OEM drawing).
End Fittings: Factory swaged terminals (e.g., clevis, ball, or threaded terminals)
Application: Primary Flight Control System (Tail Rotor Pitch)
Governing Specifications: Manufactured to MIL-DTL-83420 (Aircraft Control Cable), NAS, or proprietary Sikorsky specifications.
Certification Status: Must be supplied with an FAA Form 8130-3 or equivalent airworthiness tag.
Aircraft Compatibility Section
Sikorsky S-70/UH-60 Series: Various Black Hawk and derivative models (Utility, Special Operations).
Sikorsky S-92: Depending on the -043 suffix interpretation, could be utilized in the tail cone or stabilizer control runs of medium-lift utility helicopters.
Other Sikorsky Platforms: Specific models utilizing modular tail cone sections requiring this precise cable length.
Note: Control cable part numbers are extremely specific to the aircraft model, tail length, and control run. The helicopter's Illustrated Parts Catalog (IPC) and Component Maintenance Manual (CMM) are the final authority for verifying part applicability.
Applications Section
Tail Rotor Pitch Control: Transmits pilot or autopilot input to the tail rotor actuator to manage main rotor torque and provide yaw control.
Horizontal Stabilizer Pitch Trim: May be used in control runs for adjusting the incidence of the horizontal stabilizer for aerodynamic trim.
Maintenance and Overhaul: Required replacement item during 1200-hour or other major scheduled maintenance checks, as cables are life-limited components.
Why Choose the 70400-00511-043?
The 70400-00511-043 is a life-limited, flight-critical primary control cable. The control system of a helicopter is complex, with tension and stretch being integral to system rigging and control feel. Substituting this Sikorsky OEM part with an uncertified or improperly fabricated cable risks immediate tensile failure or premature fatigue failure, which will result in a total loss of directional control—a catastrophic event. Furthermore, an incorrect cable length or material (e.g., non-CRES) will lead to improper system tensioning, causing control slop (excessive play) and accelerated wear on associated pulleys and bellcranks. Always install certified OEM parts with traceable documentation to maintain the rotorcraft's stringent airworthiness standards.
The integrity of this wire rope assembly is determined by its fatigue resistance, a function of the cable's lay, construction, and material science. Control cables in rotorcraft are constantly subjected to high-cycle tension-tension fatigue and bending fatigue as they route over guide pulleys and through fairleads. The typical 7 times 19 construction—seven bundles of 19 individual wires each—maximizes flexibility and distributes bending stress across a large number of individual wires, preventing premature failure at stress concentration points. The use of CRES steel is critical because the presence of chlorides and corrosive atmospheric contaminants accelerates the formation of minute surface cracks, leading to rapid stress corrosion cracking (SCC) and subsequent fatigue failure. The factory-swaged terminal fittings are attached via a cold-working process that must exceed a specified percentage of the cable's ultimate tensile strength (UTS) to ensure the termination is not the weakest point of the assembly.
Note: The 70400-00511-043 is a life-limited, primary flight-critical component. It must be replaced at the hourly or calendar life limit defined by the Sikorsky maintenance schedule. Installation must be performed by a certified A&P mechanic using specialized swaging and tensioning tools (e.g., Tensiometer and Swaging Press), and strictly in accordance with the Sikorsky Maintenance Manual procedures, including final control system rigging and tension verification.
Documentation
Sikorsky Component Maintenance Manual (CMM) for Control Cables: Essential for life limits, discard criteria, and installation procedures.
Sikorsky Illustrated Parts Catalog (IPC): Required for definitive part number verification.
MIL-DTL-83420: Standard Specification for Aircraft Control Cable (Reference).