NP-27TM

Reserve hydraulic power from the NP-27TM station

Within the hydraulic system, the NP-27TM works as a reserve hydraulic power source. It delivers working fluid under pressure to actuating mechanisms, valves, locks and auxiliary hydraulic consumers, depending on the aircraft layout. This is especially important for systems where loss of hydraulic pressure may affect cargo handling, control of mechanisms, emergency actuation or auxiliary functions. The station does not replace the full main hydraulic system in all modes, but it gives the aircraft an independent pressure source for defined tasks.

NP-27TM with D-880T electric motor

The NP-27TM is driven by a D-880T DC electric motor operating from the aircraft 27 V electrical system. This allows the pumping station to be switched electrically when hydraulic pressure is required. Since the motor consumes significant current, the condition of wiring, contactors, circuit protection and power supply is important for reliable operation. Low voltage, weak contacts or poor electrical connections can reduce motor speed and prevent the station from reaching normal hydraulic pressure.

Rotary non-regulated pump in the NP-27TM

The hydraulic pump section of the NP-27TM is a rotary, non-regulated pump. It supplies a fixed flow range and develops the required hydraulic pressure according to system demand and resistance. The station works with AMG-10 hydraulic fluid, so fluid cleanliness and correct maintenance of the hydraulic circuit are important. Contaminated fluid, blocked filters, air in the system or excessive leakage in downstream consumers can make the station appear faulty even when the pump and motor are serviceable.

Installation and orientation of the NP-27TM station

The NP-27TM may be installed in a horizontal or vertical position, with the electric motor facing upward where the installation requires it. Correct mounting orientation, hydraulic line connection and electrical wiring must follow the aircraft maintenance documentation. Since the unit combines an electric motor and hydraulic pump, both vibration resistance and hydraulic tightness matter. Before installation, technicians should check mounting points, connectors, fittings, seals, motor condition, pump condition and signs of leakage or corrosion.

Aircraft application of the NP-27TM

The NP-27TM is used on fixed-wing aircraft and helicopters, including MiG-21, Tu-154S, Mi-8TV5-1 and Mi-17, depending on the hydraulic system configuration. It may support reserve hydraulic circuits, cargo-related mechanisms and other auxiliary consumers. Exact applicability should always be confirmed by the aircraft parts catalog, hydraulic system diagram and equipment list. Similar hydraulic stations may differ by pressure setting, motor type, mounting layout, flow rate and installation fittings.

Supply and inspection of NP-27TM

For procurement or replacement, the full designation NP-27TM should be used. The unit may be supplied new, from storage, repaired, overhauled or tested serviceable, depending on availability. Before installation, it should be checked for electric motor condition, pump performance, leakage, hydraulic fitting condition, cleanliness, connector condition and documentation. For aircraft use, passport, bench-test record, repair documents or technical documentation from PJSC “Volchansky Aggregate Plant” should be confirmed where available.