The KI 256 uses a standard 3-inch ATI cutout, but depth is critical. The manual specifies:
The KI 256 must be aligned within ±0.5 degrees of the aircraft’s longitudinal and lateral axes. Shims (P/N 070-0012-0500 series) are available for correction.
Use approved flexible instrument hoses to connect the aircraft vacuum line to the rear pressure port. Use a calibrated vacuum gauge to ensure air pressure reads between 4.5 and 5.2 in. Hg at engine idle and cruise RPMs. 4. Electrical Wiring & Interface Architecture ki 256 installation manual
Warning: Using an outdated or incorrect manual may lead to improper torque settings on the gyro gimbals, causing precession errors.
The following sections outline the step-by-step installation process for the KI 256 device. The KI 256 uses a standard 3-inch ATI
Before starting the installation process, ensure you have:
This modification is required when mating the indicator with a KC 192 autopilot computer (specifically Part Number 065-0042-15 ). Without this modification, electrical loading can distort pitch and roll outputs, causing sluggish or erratic autopilot response. Standard Wiring Considerations KI 256 Flight Command Indicator Mod | PDF - Scribd Use approved flexible instrument hoses to connect the
The BendixKing KI 256 Flight Command Indicator serves as a primary attitude source requiring precise installation within 4.50 to 5.00 in. Hg vacuum parameters. Installation, governed by Honeywell manuals like SB 11, demands careful handling, specifically adhering to the 5-minute rule to prevent damage to the command bar mechanism. For full product details, visit BendixKing peter2000.co.uk KI 256 Flight Command Indicator
| Pin | Function | Wire Color (Typical) | Notes | |-----|----------------|----------------------|-----------------------| | 1 | +14V DC Power | Red | 1A circuit breaker | | 2 | Power Ground | Black | | | 3 | Pitch Synchro Stator A | White/Blue | To autopilot computer | | 4 | Pitch Synchro Stator B | White/Green | | | 5 | Pitch Synchro Stator C | White/Orange | | | 6 | Roll Synchro Stator A | Yellow/Blue | | | 7 | Roll Synchro Stator B | Yellow/Green | | | 8 | Roll Synchro Stator C | Yellow/Orange | | | 9 | Rotor Excitation (26V 400Hz) | Brown | From autopilot | | 10 | Rotor Common | Brown/White | | | 11 | Internal Lighting HI | Gray | See dimmer circuit | | 12 | Internal Lighting LO | Gray/Black | Ground for lighting | | 13-24 | Not used / Test points | – | Factory use only |