PU-25

Manual input function of PU-25

The main function of the PU-25 is manual entry of service and identification information needed by the onboard recorder. This may include operational data required for correct flight data handling, depending on the system configuration. The panel allows the crew or maintenance personnel to interact with the recorder before or during operation. Correct input matters because service data may be linked with the recorded flight archive and later used during decoding or post-flight analysis.

PU-25 control and indication role

The PU-25 provides control of recording-related processes and visual indication of system status. Through the panel, the crew can monitor whether the recording equipment is ready and whether the system is operating as required. This makes the PU-25 an important operational interface, even though the actual collection and storage of data are performed by other units of the recorder system. If the indication is incorrect, the fault may be in the panel, wiring, power supply or connected BUR equipment.

PU-25 in the BUR-1-2Zh system

The PU-25 is included in the BUR-1-2Zh onboard flight data recorder system. In a typical system, it works together with units such as the BSPI-4-2 data acquisition unit, protected onboard recorder ZBN-1-1 and mounting frame RA-37K. The BSPI collects and processes signals, the protected recorder stores data, and the PU-25 provides control and indication for the system. This separation is important when ordering spare parts: the PU-25 is one unit of the system, not the complete recorder set.

Helicopter application of PU-25

The PU-25 is installed on helicopters equipped with BUR-1-2Zh flight data recording systems. It is used as the standard interface element between the crew and the onboard recorder. The exact installation point depends on the helicopter cockpit layout, recorder configuration and wiring diagram. Before replacement, the panel version, connector arrangement, voltage supply and compatibility with the installed BUR-1-2Zh system should be checked against the aircraft documentation.

Electrical supply and readiness of PU-25

The panel operates from the aircraft DC power system and may also use secondary ±15 V supply lines depending on the system arrangement. Time to readiness is short, which allows the panel to become available quickly after system power-up. For troubleshooting, it is not enough to check the panel only by external condition. Supply voltage, secondary sources, connector contacts, indication elements and command output to the recorder system should all be verified.

Supply and inspection of PU-25

For procurement or replacement, the full designation PU-25 / PU-25 should be specified. It is also useful to confirm the helicopter type, recorder system version, condition and documentation requirements before shipment. Before installation, the unit should be checked for housing condition, front-panel controls, indication elements, connector integrity, power consumption, readiness time and compatibility with the BUR-1-2Zh system. Product passport and manufacturer documentation should be confirmed where available.