8A-4101-00B-1

8A-4101-00B-1 in the main landing gear system

The 8A-4101-00B-1 is a hydropneumatic shock absorber installed on the right main landing gear of Mi-8, Mi-17, Mi-171 and Mi-172 helicopters. It is part of the main landing gear assembly and works during every landing, taxiing movement and ground maneuver. The unit takes the first impact loads from the wheel and landing gear structure, then reduces the force transmitted further into the helicopter airframe. For this reason, the shock absorber is not just a suspension part; it is one of the main load-absorbing elements of the landing gear system.

Landing impact absorption by 8A-4101-00B-1

During landing, the main landing gear receives vertical and dynamic loads from contact with the ground. The 8A-4101-00B-1 absorbs part of this energy through the movement of the rod inside the shock absorber body. Hydraulic fluid is forced through calibrated passages and valve elements, slowing down the movement and converting part of the impact energy into heat. At the same time, the nitrogen chamber works as an elastic element. This combination allows the landing gear to soften the touchdown and reduce peak loads on the structure.

Right-side installation of 8A-4101-00B-1

The designation 8A-4101-00B-1 refers to the right-side shock absorber. The corresponding left-side unit is normally identified as 8A-4101-00B-2. This distinction is important when ordering or replacing the part, because the two sides may be mirrored by installation fittings and layout. In maintenance or supply requests, the side of installation should always be stated clearly. A wrong-side shock absorber may have the same general purpose but will not necessarily match the helicopter landing gear assembly.

Hydraulic and nitrogen operation of 8A-4101-00B-1

The 8A-4101-00B-1 works as a liquid-gas shock absorber. Hydraulic fluid AMG-10 is used inside the working cavity, while technical nitrogen provides the gas charge. On compression, the rod moves inward and the oil flow is restricted by internal passages and valves. On rebound, the unit controls reverse movement so that the landing gear does not extend sharply after impact. This two-way damping behavior helps the helicopter remain stable after touchdown and during movement over uneven ground or rough surfaces.

Internal components of 8A-4101-00B-1

The shock absorber assembly includes a cylinder, rod, bushings, valve elements and sealing parts. The internal group may include components such as piston and guide bushings, diffuser elements, check valves, piston rings, cuffs, gland seals and sealing rings. These parts work together to keep pressure, control oil flow and prevent leakage. During repair or overhaul, the condition of sealing surfaces, bushings, rod chrome, valve parts and hydraulic cleanliness is critical. Even small damage inside the unit can affect damping behavior or lead to leakage under load.

Ground operation and service role of 8A-4101-00B-1

The 8A-4101-00B-1 is active not only at the moment of landing. It also works during taxiing, braking, turning and ground handling, especially when the helicopter moves over uneven concrete, prepared soil or airfield surfaces with local defects. If the shock absorber loses pressure, has internal leakage or does not move correctly, the landing gear may transmit higher loads to the frame and create abnormal behavior on the ground. For this reason, the unit is checked for visible leakage, correct extension, pressure condition, mechanical damage and service documentation.

Supply and identification of 8A-4101-00B-1

When ordering the 8A-4101-00B-1, the full designation and right-side installation must be confirmed. It is also useful to specify whether the requirement is for a complete shock absorber assembly, an overhauled unit, a storage item, or a unit with a current passport and test records. For aircraft use, documentation is important because the shock absorber has landing-based resource limits and service life limits. Before installation, the unit should be checked against the helicopter parts catalog, maintenance manual and passport data.

Product Type: Main landing gear hydropneumatic shock absorber
Designation: 8A-4101-00B-1
Alternative Designations: 8А-4101-00Б-1; 8A-4101-00B-1
Function: Absorption of landing impact loads and damping of dynamic forces
Application / Where Used: Helicopter main landing gear systems
System / Installation Area: Main landing gear, right side
Part of System / Included in Set: Main landing gear assembly
Side of Installation: Right side
Left-Side Equivalent: 8A-4101-00B-2 / 8А-4101-00Б-2
Compatible Aircraft / Equipment: Mi-8, Mi-17, Mi-171, Mi-172
Operating Principle: Hydropneumatic damping with hydraulic fluid and nitrogen charge
Working Medium: Hydraulic fluid AMG-10
Gas Charge: Technical nitrogen
Operating Pressure: 6.0 MPa
Operating Stroke: 0–60 mm
Operating Temperature Range: −60 to +60 °C
Main Internal Components: Cylinder, rod, piston and guide bushings, valve group, seals and sealing rings
Example Component References: 8A-4101-17, 8A-4101-20, 8A-4101-27A, 8A-4101-18, 8A-4101-14, 8A-4101-02, 8A-4101-11, 8A-4101-12, 8A-4101-13
Weight: 26.5 kg
Assigned Resource: 4000 landings
Inter-Repair Resource: 2600 landings
Assigned Service Life: 10 years
Storage Life: 2 years
Scope of Supply: Shock absorber assembly
Technical Documentation: Passport 8A-4101-00B PS

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.