TV3-117VM

High-altitude function of the TV3-117VM

The TV3-117VM modification is intended to maintain stable engine performance in high-altitude conditions. Reduced air density normally affects engine output, especially during takeoff, hover and maneuvering at elevated sites. The VM version is optimized to support helicopter operation at operating altitudes of approximately 3000–4000 m above sea level, depending on aircraft configuration and environmental conditions. This capability is important for helicopters working in mountainous regions, hot climates and remote landing zones where available power margin can directly affect operational flexibility and safety.

Power output of the TV3-117VM engine

The TV3-117VM provides takeoff power for normal high-load operating modes and can support short-term emergency power when required. Emergency power gives the helicopter additional performance margin in abnormal or demanding situations, such as engine-out procedures, difficult takeoff conditions or urgent maneuvering. The engine’s power characteristics allow Mi-family helicopters to perform transport, utility and special missions while retaining stable operation under variable load. Power setting, duration and permitted use of emergency modes must always follow the aircraft and engine operating documentation.

Free-turbine design of TV3-117VM

The TV3-117VM uses a free-turbine configuration. This design separates the gas generator from the power turbine that drives the helicopter transmission, allowing efficient torque delivery under changing rotor load. The engine operates through the helicopter transmission system rather than driving the rotor directly. This arrangement supports stable operation during takeoff, hover, cruise, descent and maneuvering. Since the engine works with the main gearbox and rotor system, technical condition of the engine, fuel system, control system, exhaust path and transmission interfaces must be considered together during maintenance.

Aircraft application of the TV3-117VM

The TV3-117VM engine is used on Mi-8MT, Mi-8MTV, Mi-24 and Mi-28 helicopters, depending on aircraft modification and installed powerplant configuration. It is suitable for civil and military helicopter applications where the approved engine installation and documentation correspond to this engine type. Since Mi-series helicopters may differ by production year, modernization, gearbox configuration, control system and service bulletin status, applicability should be confirmed through the aircraft parts catalog, engine records and operational documentation before supply or installation.

Identification and supply of TV3-117VM

Before ordering a TV3-117VM engine, the exact designation, modification, condition, documentation set and remaining life should be confirmed. The engine may be supplied in different conditions depending on availability and customer requirements. For operational use, documentation is essential because serviceability depends not only on physical condition, but also on recorded operating time, overhaul status, storage conditions and life limits. For correct supply, it is useful to specify aircraft type, required configuration, engine condition, passport availability, logbook records and whether accessories are included.