PU-1248 Series 2

Autopilot control function of PU-1248 Series 2

The PU-1248 Series 2 panel allows the crew to control aircraft motion relative to the longitudinal, lateral and vertical axes through the autopilot system. It supports engagement and management of pitch, roll and heading-related control channels, depending on the aircraft configuration. The panel does not operate as an independent autopilot computer; it is a cockpit command interface connected with the AP-28 automatic flight control equipment. Crew commands from the panel are transmitted to the autopilot system, where they are processed and converted into control actions.

Flight stabilization through PU-1248

The PU-1248 panel is used for maintaining selected flight parameters through the AP-28 system. These functions may include stabilization of barometric altitude, roll angle, pitch attitude and heading. The panel also allows the crew to enter manual corrections to the flight path and to monitor selected autopilot states. In operation, it helps the crew maintain a stable flight path during cruise, route following and other phases where autopilot use is permitted by aircraft procedures. Correct function depends on the autopilot channels, sensors, wiring and indication system.

PU-1248 interaction with AP-28 navigation modes

In AP-28 family installations, the PU-1248 panel can support automatic flight modes connected with route guidance and navigation. These may include automatic flight along orthodromic and loxodromic tracks and automatic turns up to specified angles, depending on the aircraft system configuration. The panel provides the crew with manual control elements for changing flight parameters and selecting channels or modes. Since navigation and autopilot equipment can differ between An-24, An-26 and related aircraft, mode availability should always be confirmed through the aircraft documentation.

Panel design and cockpit installation

PU-1248 Series 2 is designed as an aircraft cockpit panel for installation in the central console or instrument panel area. The unit is built as a compact monoblock and includes electromechanical controls for manual correction and autopilot channel operation. Typical panel elements include the “Turn” rotary control, the “Descent-Climb” rotary control, channel engagement buttons or switches and light annunciators for mode and fault indication. The panel housing is intended for operation in aircraft cockpit conditions, including vibration, temperature variation and long-term service use.

Identification and ordering of PU-1248 Series 2

PU-1248 Series 2 may be supplied in different versions depending on the associated AP-28 autopilot modification. PU-1248D Series 2 is associated with the AP-28L1 system, while PU-1248E Series 2 is associated with the AP-28L1I system. Before ordering, the aircraft type, autopilot version, exact panel index, required condition, connector configuration and documentation set should be confirmed. The unit may be required for operational replacement, overhaul support, cockpit restoration or spare parts stock for An-24 / An-26 aircraft maintenance.