AU-1056

AU-1056 three-channel architecture

The AP-28L1 stabilizes and controls aircraft motion in roll, pitch and heading and also supports barometric-altitude stabilization. AU-1056 follows this three-channel architecture: its elements are arranged in separate roll, pitch and heading cassettes for service access and replacement. Common relays, blocking elements and the mating portions of the cassette connectors are installed on the assembly base.

AP-28L1 interfaces and aircraft application

In the AP-28L1 system, AU-1056 receives information from attitude, angular-rate, heading and altitude channels and supplies control commands toward the servo-amplifier and actuator chain. The system is documented on the Antonov An-24 and An-26 family; separate aviation inventories also associate AU-1056 with AP-28D1 and AP-34B variants. Exact effectivity must be checked because the same 1056 family designation does not prove compatibility with every autopilot execution.

Related AP-28L1 equipment

Documented companion equipment includes the PU-1248 control panel, BT-1426 trim block, KV-11 altitude corrector, BS-1408A course-system interface, DUS-970V angular-rate sensor, relay and servo-amplifier blocks, trim machine and three steering machines. These are separate units with their own part numbers; cross-sells identify system relationships, not interchangeability.

Inspection and ordering AU-1056

Before installation, inspect the enclosure, base, cassette retention, connectors, contacts, seals and complete data plate. Functional testing requires an approved AP-28L1 bench or equivalent simulation of the input and output circuits. Standalone supply values, pin assignments, dimensions and mass must be taken from the exact AU-1056 passport. An enquiry should state AU-1056, autopilot execution, aircraft type, quantity and documentation. More units are listed under Electronic Control Units.