BUKI-400

Control functions of the BUKI-400 unit

The BUKI-400 forms and distributes control signals for spoiler actuation. These signals are used by electrohydraulic valves, actuators or steering units that control the movement of spoiler panels. Depending on aircraft configuration and operating mode, the unit may support separate or synchronized control of left and right spoiler groups, including brake spoilers and aileron-spoilers. This makes the unit part of the logic chain between cockpit commands, aircraft sensors, hydraulic actuators and actual spoiler panel movement.

BUKI-400 operating modes

The spoiler system may work in manual and automatic modes, depending on aircraft logic. In manual mode, spoiler deployment is commanded from the cockpit control handle or lever on the pilots’ central panel. In automatic mode, spoiler deployment may be linked to landing conditions, including signals from landing gear shock strut compression switches after touchdown. The BUKI-400 processes these inputs and supports the required control response. This is especially important during landing rollout, when spoiler deployment helps reduce lift and improve braking effectiveness.

Monitoring and failure control by BUKI-400

Besides command formation, the BUKI-400 performs monitoring functions. It checks the condition of control channels and participates in failure indication to the crew. The unit receives signals from position sensors and control circuits, compares input values and monitors the operation of connected channels. If the system detects abnormal behavior, loss of signal or channel mismatch, warning information may be sent to cockpit indicators or central annunciation panels. This monitoring role is important because spoilers affect aircraft controllability and landing performance.

BUKI-400 interaction with aircraft systems

The BUKI-400 is integrated with several aircraft systems. It receives commands from spoiler controls in the cockpit, interacts with roll-control channels or related control-wheel position sensors where applicable, receives landing gear compression signals, and sends commands to hydraulic control elements. It is powered from the aircraft 27 V DC network. In typical system architecture, the unit may also work together with other wing mechanization control units, including the BUKZ-400 flap control and monitoring unit, depending on aircraft configuration.

Electrical signals and sensor interfaces of BUKI-400

The BUKI-400 works with the aircraft DC power network and with potentiometric sensor circuits. It supplies reference voltage to potentiometric sensors and receives variable input signals from them. These values are used for control logic and position monitoring. Correct operation depends on stable supply voltage, clean connector contacts, proper sensor adjustment and correct wiring in the aircraft harness. During troubleshooting, technicians usually check supply voltage, sensor voltage ranges, channel balance, output signals and actuation thresholds.

Installation and maintenance of BUKI-400

The BUKI-400 is built as a removable aircraft block for installation in onboard equipment racks, radio compartments or dedicated mounting frames, depending on the aircraft layout. The unit has a rear connector and is normally checked using specialized ground test equipment. Maintenance and repair are performed on test benches with DC power distribution and measuring instruments such as voltmeters and signal simulators. For aircraft installation, visual inspection alone is not enough; the unit must be checked by control signals, output response, monitoring channels and documentation.

Supply and documentation for BUKI-400

For supply, the unit should be requested by its full designation: BUKI-400 spoiler control and monitoring unit. The aircraft type, required condition, documentation and modification status should be confirmed before shipment. Since this is a control and monitoring unit for aircraft wing systems, interchangeability and serviceability must be verified through aircraft maintenance documentation, wiring diagrams and bench-test records. When supplied from storage or after repair, the passport, acceptance records and test results are important for confirming suitability for installation.