246-1517-000

Torque transmission through the 246-1517-000 gearbox

The 246-1517-000 gearbox transmits torque, changes the direction of power flow and provides the required speed relationship for tail rotor operation. Power reaches the unit from the main transmission through the intermediate gearbox and tail shaft system. Inside the tail gearbox, the bevel gear arrangement redirects rotation to the tail rotor output. This allows the tail rotor to produce anti-torque thrust and provide yaw control. Since the unit operates under continuous mechanical load, the condition of gears, bearings, lubrication passages and sealing elements is important for stable transmission performance.

246-1517-000 on Mi-family helicopter applications

The 246-1517-000 tail gearbox is used on Mi-family helicopters equipped with compatible tail rotor drive systems. Typical applicability includes Mi-8, Mi-17, Mi-171, Mi-8AMT, Mi-8MTV, Mi-172, Mi-14 and Mi-24 / Mi-25 / Mi-35 configurations, depending on aircraft documentation and installed transmission equipment. Because these helicopters may differ by modification, repair history and service bulletin status, applicability should be confirmed through the aircraft parts catalog and maintenance documentation. A visually similar tail gearbox should not be treated as interchangeable without checking the exact designation and approved configuration.

Lubrication and thermal operation of 246-1517-000

The 246-1517-000 gearbox has an internal lubrication system intended to support gear and bearing operation during continuous flight cycles. The oil works under mechanical load, temperature variation and vibration typical for helicopter tail transmission units. Correct oil type, fill quantity and temperature control are important because inadequate lubrication can increase wear, heating and risk of damage to gear teeth or bearing surfaces. Winter operation may require the specified oil mixture according to the applicable documentation. During maintenance, oil condition, leakage, contamination and metal particles should be checked together with gearbox service records.

System integration of the 246-1517-000 tail gearbox

The 246-1517-000 is installed as part of the full tail rotor drive and control system. It interfaces with the tail transmission shaft line, tail boom mounting structure, tail rotor hub area and control-related assemblies. The housing is designed for installation at the tail end of the helicopter and supports the internal bevel gear arrangement under vibration and changing flight loads. Since the gearbox is part of a rotating transmission system, correct mounting, alignment, oil filling, sealing and documentation compliance are all important during overhaul or replacement.

Identification and interchangeability of 246-1517-000

The gearbox may be referenced under several designations, including 246-1517-000, 2461517-000, 246-1517-00 and 2461517000. It may also be interchangeable with 8AT-1730-000 after modification according to bulletin M-466DM. This interchangeability should not be assumed by part number alone. The modification status, helicopter type, installed shaft system, documentation and service bulletin compliance must be verified before installation. For correct ordering, it is useful to specify the aircraft type, required condition, passport availability, overhaul status and whether service or storage documentation is included.