LUN 6223-8

Function of LUN 6223-8 in the Safir-5 APU system

The main function of LUN 6223-8 is to supply aviation fuel to the Safir-5 auxiliary power unit. In the L-39 system context, the Safir-5 unit is used during aircraft start procedures and ground power support operations. The pump delivers fuel from the aircraft fuel circuit toward the APU / turbo starter fuel system and supports the required pressure and flow for reliable starting operation. According to the supplied context, the pump works together with the LUN 6743 fuel distributor in the Safir-5 fuel control circuit.

Application on L-39 aircraft

LUN 6223-8 is referenced for aircraft of the L-39 family, including L-39C and L-39ZA variants, depending on aircraft configuration and maintenance documentation. The unit is installed in the system related to APU fuel supply, starting and turbo starter operation. Since L-39 aircraft may differ by version, overhaul status and operator configuration, exact applicability should be confirmed by the aircraft illustrated parts catalogue, electrical diagrams, fuel system documentation and Safir-5 maintenance section.

Construction of the LUN 6223-8 pump

The supplied context describes LUN 6223-8 as a single-stage gear-type pump with one pumping section and an integrated DC electric motor. Structurally, the unit is a compact cylindrical assembly with two coaxial parts: the electric drive section and the hydraulic gear pump section. The pump has fuel inlet and outlet ports for connection to aircraft fuel pipelines and an electrical connection for DC power supply. Depending on installation version, the unit may be mounted by flange or clamp arrangement on the APU / Safir-5 installation structure.

Fuel and operating environment

LUN 6223-8 is intended for aviation fuel service. The supplied data references T-1, TS-1, RT and foreign equivalents such as Jet A-1 as working media. In operation, fuel cleanliness, line sealing, correct inlet / outlet orientation and electrical supply stability are important for normal pump performance. During inspection or replacement, maintenance personnel should check the pump body, ports, connector or terminals, mounting condition, leakage signs, fuel pressure output and compliance with aircraft maintenance procedures.

Identification and supply of LUN 6223-8

When ordering LUN 6223-8, the complete designation should be specified together with the aircraft type and intended installation. The buyer should confirm whether the requirement is for a serviceable pump, overhauled pump, as-stored unit or item for repair / exchange. If exact dimensional data, connector pinout, port thread, mounting distance or overhaul life is required, those values should be checked against the L-39 technical operation manual, Safir-5 section and the individual product passport / form.