Ki 256 Installation Manual

The is a self-contained vertical gyroscope used in high-performance BendixKing flight control systems like the KFC 150 and KFC 200. Because this is a critical flight instrument, physical installation and maintenance must be performed by authorized personnel using the official KI 256 Maintenance Manual or the relevant Flight Control System Installation Manual.

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Apply primary DC power to the aircraft bus and verify the Gyro Warning Flag remains in view.

The BendixKing KI 256 serves as a critical attitude and flight command indicator, requiring strict adherence to engineering standards for installation and integration with legacy autopilots. Key procedures include implementing Service Bulletin 11 for modified command bar boards and precise pneumatic calibration at 4.5 in. Hg. Detailed installation, modification, and maintenance, including Service Bulletin 11, can be found in the documentation provided by peter2000.co.uk KI 256 Flight Command Indicator ki 256 installation manual

The KI 256 uses a standard dual-row edge connector or a high-density circular plug depending on the modification status. Below is the standard pinout configuration for the autopilot interface signals. Pin Identifier Signal Name Function Description Gyro Common Ground reference for internal synchros Pin B Pitch Excitation 400 Hz AC input reference from autopilot Pin C Roll Excitation 400 Hz AC input reference from autopilot Pin D Pitch Pickoff Hi Pitch attitude error output signal Pin E Pitch Pickoff Lo Pitch attitude error return path Pin F Roll Pickoff Hi Roll attitude error output signal Pin G Roll Pickoff Lo Roll attitude error return path Pin H Flight Director Bar + Command bar upward deflection drive Pin J Flight Director Bar - Command bar downward deflection drive Pin K 28 VDC Lighting Panel backlight power supply Pin L Chassis Ground Airframe electrical ground connection Wiring Guidelines

4.5 to 5.2 inches of mercury (in. Hg)

Installing a KI 256 is not a simple "plug and play" task. To ensure the autopilot tracks correctly, a system alignment is typically required: Field Alignment : Alignment should ideally be done at the aircraft using a gyro tilt stand The is a self-contained vertical gyroscope used in

| Symptom | Likely Cause | Solution | |---------|--------------|----------| | No attitude display, but power on | Missing 400Hz AC reference from remote gyro | Check continuity on pins 4 & 6 | | Erratic flight director bars | Shield not grounded at source | Terminate shield at remote gyro case | | Slow gyro spin-up | Low voltage drop across circuit breaker | Measure voltage at pin 1 under load (min 11.5V for 14V system) | | Flag “GYRO” visible after warm-up | Remote gyro failure or disconnected | Verify KG 258 or KG 102 power & wiring | | Roll indicates opposite direction | Synchro stator leads swapped | Swap any two of pins 12/13/14 |

| Symptom | Likely Cause | Solution | |---------|--------------|----------| | OFF flag visible | No vacuum or gyro not spun up | Check vacuum line and electrical power | | Roll flag only | Missing roll command return (pin H) | Verify wiring continuity | | Bars stuck full scale | Command signal shield grounded at KI 256 | Remove ground loop — shield only at source | | Erratic attitude | Vacuum too high or low | Adjust regulator to 5.0 inHg | | No backlight | Voltage mismatch (28V to 5V lamp) | Install dropping resistor per manual Fig 6-3 |

: Accepts DC drive currents from the computer to steer the single-cue command bars dynamically over the attitude horizon. Hg. Detailed installation

Note: The KI 256 is a real attitude indicator (part of the King KCS 55/55A compass system). This is a technically plausible excerpt, not an official manual.

The BendixKing KI 256 is a legacy flight command indicator. It combines a flight director with an air-driven attitude gyroscope. This unit acts as the primary attitude source for many premium autopilot systems, including the KFC 200 and KFC 225.

: Level the precision tilt stand exactly using the integrated bubble levels. Ensure the non-tested axis remains locked precisely at zero.

Before beginning installation, ensure the unit matches your aircraft's electrical and physical configuration.

Because the KI 256 acts as the primary attitude sensor for legacy autopilot systems, a precise installation in strict compliance with the instructions is crucial. This article provides a comprehensive overview of the technical specifications, physical mounting, wiring design, calibration requirements, and troubleshooting procedures specified in the official installation literature. 1. System Overview and Autopilot Compatibility