8-3904-000

8-3904-000 is a tail rotor assembly designed for Mi-8 family helicopters and their derivatives. The assembly is a critical component of the helicopter tail rotor system and is intended to compensate the main rotor reactive torque as well as to provide helicopter yaw (directional) control.

The tail rotor is of a three-blade, variable-pitch, reversible design, allowing the generation of the required lateral thrust across all standard flight regimes. The assembly is installed on the helicopter tail boom and operates under significant aerodynamic and mechanical loads.

The 8-3904-000 tail rotor assembly consists of the tail rotor hub 8-3901-000, which serves as the primary load-bearing and control-transmission unit, and a set of tail rotor blades 8-3922-000. The hub provides blade attachment and pitch control, while the blades generate aerodynamic thrust.

The tail rotor assembly is used on Mi-8, Mi-14, Mi-17, Mi-24 and related helicopter models. The product is manufactured by Moscow Machine-Building Plant “Vpered” (MMZ “Vpered”), the sole authorized manufacturer of this type of tail rotor in the Russian Federation. Depending on supply configuration, the unit may be delivered as a complete assembly or as individual components for overhaul and maintenance purposes.

Purpose: Compensation of main rotor torque and helicopter yaw control
Systems: Helicopter tail rotor system
Application: Mi-8, Mi-14, Mi-17, Mi-24 and related helicopter models
Product Type: Tail rotor assembly
Designation: 8-3904-000
Rotor Configuration: Three-blade, variable-pitch, reversible
Rotor Diameter: 3.908 m
Installation Location: Helicopter tail boom
Assembly Composition: Tail rotor hub 8-3901-000, tail rotor blades 8-3922-000
Functional Role of Hub: Blade attachment and transmission of control forces
Functional Role of Blades: Generation of lateral thrust
Manufacturer: Moscow Machine-Building Plant “Vpered” (MMZ “Vpered”)
Supply Configuration: Complete assembly or individual components
Condition: As applicable
Documentation: Component logbook and operational documentation available upon request

All shipments are carried out from our international warehouse in Dubai (UAE), as well as from our partners’ remote warehouses.

In Stock — items available in stock at the Dubai warehouse are dispatched within 5–10 business days after receiving 100% prepayment.

Remote Stock — items available at our partners’ remote warehouses are supplied within an average of 30–45 business days after receiving 100% prepayment.

Pre-Order — made-to-order products are manufactured and delivered within an average of 45–60 business days. Payment terms: 50% advance payment to start production, with the remaining 50% paid before dispatch from the Dubai warehouse after full readiness for shipment.

Returns & Changes (Restocking Fee)
For selected items, a RESTOCKING FEE of 10% may apply in case of return, order cancellation, or changes to the order specifications. This condition applies only to certain products and is confirmed at the order approval stage.

Warranty
All products are covered by a standard 6-month warranty.
Extended warranty is available upon request and is agreed individually; it may affect the final product price.