ECNG-5-2

In-tank installation of the ECNG-5-2 pump

The ECNG-5-2 is designed for installation inside aircraft wing or fuselage fuel tanks. This in-tank layout reduces the number of external fuel lines and helps lower the risk of fuel leakage outside the tank. On Yak-42 aircraft, pumps of this type are installed inside the wing side caisson tanks, typically two pumps in each side caisson. They are mounted in special installation devices with removable shutters, allowing pump removal without draining the tank. This is a practical feature for maintenance and reduces aircraft downtime during replacement.

Fuel supply and transfer function of ECNG-5-2

The pump provides high fuel flow and creates the required outlet pressure for fuel supply, transfer between tank sections and booster feed before the main engine fuel pumps. On Yak-42 aircraft, the ECNG-5-2 supplies fuel to the D-36 side engines and supports the operation of jet pumps such as SN8-1, depending on the aircraft fuel system configuration. On aircraft such as An-124 and MiG-29, the pump is used in a similar role for in-tank boosting, transfer and creation of inlet pressure for downstream fuel equipment.

Sealed construction of the ECNG-5-2

The ECNG-5-2 is built as a sealed electric centrifugal pump. The design separates the fuel hydraulic part from the electric motor cavity and prevents fuel vapor from entering the motor section. This is important for aircraft fuel tank operation, where the pump works directly in a fuel environment. The unit is intended for long service under vibration, fuel exposure and changing operating conditions. During inspection, attention should be paid to sealing condition, housing integrity, connector condition, mounting flange, inlet screen or flow path, and any signs of corrosion or contamination.

Electric drive of the ECNG-5-2

The ECNG-5-2 is equipped with a DC electric motor of the ETM-101 series. The motor drives the centrifugal pumping section at high rotational speed, allowing the pump to deliver fuel at the required flow rate and pressure. The nominal operating current is relatively low for the pump’s output, which makes it suitable for onboard aircraft DC electrical systems. Correct electrical operation depends on stable supply voltage, motor insulation, connector condition and proper current consumption during load testing.

ECNG-5-2 on Yak-42, An-124 and MiG-29 aircraft

The ECNG-5-2 is used on several Soviet-designed aircraft types, including Yak-42, An-124 Ruslan and MiG-29, depending on the fuel system version. On Yak-42, it is associated with the wing caisson tank system and fuel supply to D-36 engines. On An-124 and MiG-29, it can be used for in-tank transfer and booster fuel supply. Since fuel system architecture differs between aircraft, applicability must always be checked by aircraft type, modification, tank layout and parts catalog before installation or supply.

Maintenance and replacement of ECNG-5-2

For maintenance, the ECNG-5-2 should be checked not only visually, but also by performance. Important checks include pump delivery, outlet pressure, current consumption, rotational operation, sealing, connector condition and mounting interface. If the aircraft uses a removable tank installation device, the pump may be replaced without fuel draining, provided the aircraft maintenance procedure allows it. Before installation, the pump should be matched with the correct aircraft fuel system documentation and accepted with passport or test records when available.