Ki 256 Installation Manual Jun 2026

| Pin / Signal Type | Purpose / Details | | :--- | :--- | | | Configurable for 14V DC or 28V DC systems. At either voltage, it draws a maximum of 0.7 amps. Also requires a 10V AC, 430Hz supply with a 0.2 amp maximum draw. | | Ground | A dedicated ground pin for the instrument’s internal electronics and DH (Decision Height) light. | | Flight Director Signal Input | Receives pitch and roll command signals from the flight computer (e.g., KC 295). This is a critical data link for command bar movement. | | Attitude Reference Signal Output | Provides a pitch/roll reference signal back to the flight computer. | | DH Annunciator | The optional Decision Height light receives its power (14V or 28V) through the aircraft’s radar altimeter wiring. |

💡 When aligning a radar altimeter or other system that uses the KI‑256 gyro as a reference (e.g., Honeywell/Bendix RDR 2000 radar), it is sometimes necessary to vibrate the gyro during alignment. This can be accomplished by simply rolling a screwdriver across the tilt table to break any stiction in the gyro gimbals.

Before removing the KI‑256, verify that the replacement is approved under an STC for your specific autopilot model, and that the backup flight director display requirements are satisfied. ki 256 installation manual

14 VDC or 28 VDC (Internal lighting configuration depends on the specific dash number)

The BendixKing KI 256 is an internally air-driven that serves as a central component in BendixKing flight control systems like the KFC-150, KFC-200, KFC 225, and KFC 250. It provides a pictorial display of aircraft pitch and roll while supplying attitude reference signals to the flight computer. Core Installation Specifications | Pin / Signal Type | Purpose /

system. Detailed pinouts and mounting instructions are generally found in the KFC 200 installation documentation KFC 150 System Installation Manual : For aircraft using the KFC 150 system , the KI 256 installation details are included in manual P/N 006-10552-XXXX KI 256 Maintenance/Overhaul Manual

Work must be performed in a clean environment to prevent contaminants from entering the vacuum ports, which can cause gyro precession. Electrical & Vacuum Connections | | Ground | A dedicated ground pin

Connect the vacuum supply to the intake port on the rear of the chassis. Use a 1/4-inch flexible hose certified for aviation use. Secure the hose with a approved clamp to prevent pressure leaks. Electrical Wiring and Pin Configuration

Turn on the vacuum system and verify the instrument gauge reads between 4.5 and 5.2 in. Hg.

19.43 cm (7.65 inches) including connectors Weight: 1.54 kg (3.40 lbs) Electrical Inputs