TV3-117VM Series 2

OEI safety function of TV3-117VM Series 02

The TV3-117VM Series 02 supports one-engine-inoperative operation. In the event of one engine failure on a twin-engine helicopter, the remaining engine must provide increased power for a limited time so the crew can continue flight, perform an approach or land safely. The engine supports short-term and extended OEI power modes, giving the helicopter an additional safety margin under abnormal operating conditions. These modes must be used strictly according to the aircraft and engine operating documentation, because duration, temperature limits and power setting are controlled parameters.

Power modes of the TV3-117VM Series 02 engine

The TV3-117VM Series 02 provides high output in emergency and takeoff-related regimes and maintains efficient operation in cruise. Power data are normally referenced to sea level, zero Mach number and ISA conditions. The engine can deliver emergency power, extended OEI power and cruise power depending on operating mode and permitted duration. These characteristics allow Mi-8 / Mi-17 family helicopters to perform civil transport, utility and support missions while retaining the power margin required for safety-critical situations. Actual available power depends on ambient temperature, altitude, installation and aircraft configuration.

Free-turbine layout and installed accessories

The TV3-117VM Series 02 uses a free-turbine configuration, allowing the gas generator and power turbine to operate as part of the helicopter engine and transmission system. The engine is fitted with accessory equipment for starting, fuel supply, control, lubrication and electrical support. Main installed units may include the accessory gearbox, NR-3VM fuel control / pump-regulator, SV-78BA air starter or equivalent starter configuration, ERD-3VM electronic engine regulator, high-pressure fuel pump, oil system units, centrifugal breather, generator and sensors for pressure, gas temperature and vibration control.

Application of TV3-117VM Series 02 on Mi-8 / Mi-17 helicopters

The TV3-117VM Series 02 is used on helicopters of the Mi-8 / Mi-17 family, depending on aircraft modification and approved powerplant configuration. It is suitable for civil helicopter service where the aircraft documentation permits installation of this engine type. The engine may be interchangeable with other TV3-117 family engines within approved limits, but this must be checked by configuration, aircraft records, service bulletins and installation documentation. Interchangeability should not be assumed only from the engine family name, because installed accessories, control system configuration and operating limits may differ.

Identification and documentation for TV3-117VM Series 02

Before ordering or installing TV3-117VM Series 02, the exact engine designation, series, accessory configuration, condition and documentation set should be confirmed. Dry weight, power limits and installed equipment depend on the specified configuration and should be checked against the passport or technical records. For operational acceptance, the engine logbook, passport, maintenance history, storage records and remaining life are as important as the physical condition of the unit. For supply, it is useful to specify helicopter type, required condition, remaining resource, included accessories and documentation availability.