Overhauls must be performed in a clean room environment to prevent gyro contamination. 6. Common Issues and Troubleshooting
: Units are manufactured specifically for either 0-degree or 8-degree instrument panel slopes; ensure the part number matches your panel configuration. 2. Mechanical Installation
Bendix/King KI 256 Horizon Gyro: Comprehensive Installation and Maintenance Manual Guide
BendixKing KI 256 Installation Manual: The Definitive Guide for Avionics Technicians ki 256 installation manual
Allow the gyroscope to spool up undisturbed for at least 3 to 5 minutes.
: The unit measures 3.55" W x 3.37" H x 7.31" L and weighs roughly 3.3 lbs .
Requires 4.5 to 5.2 inches of mercury (in. Hg) from the aircraft vacuum pump. Operating Temperature: -30°C to +55°C. Safety Precautions Overhauls must be performed in a clean room
Connect the vacuum inlet port on the rear of the KI 256 to the aircraft vacuum regulator output. Use flexible, FAA-approved rubber vacuum hoses.
💡 The KI 256 is an overhaul-intensive unit. Modern upgrades like the KI 300 electronic indicator or Garmin GI 275 are often used to replace the KI 256 to eliminate vacuum reliability issues.
Measure the AC voltage outputs on Pins E/F (Roll) and Pins G/H (Pitch). They must read 0.0 VAC ( ±plus or minus 50mV) when the aircraft is perfectly level. Requires 4
Use a standard 3-inch ATI instrument hole. Secure the unit using four 6-32 brass non-magnetic screws.
: Position the KI 256 squarely in the pilot's primary field of view (the top-center position of the standard "Basic T" instrument cluster).
The is one of the most enduring and widely used electromechanical flight director indicators in general aviation. Operating as a self-contained vertical gyroscope, the BendixKing KI 256 displays critical aircraft pitch and roll attitudes while simultaneously feeding analog attitude data to an automatic flight control system.
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