((full)): Ki 256 Installation Manual
: If integrated with a test set like the KTS 150 or KTS 151 , technicians should verify that all test points (Roll, Pitch, Fader, etc.) meet the voltage specifications defined by BendixKing.
Turn on the vacuum system and verify the instrument gauge reads between 4.5 and 5.2 in. Hg.
The electrical connector interfaces the unit with the autopilot (e.g., KC 295 computer). ki 256 installation manual
| Pin | Function | Wire AWG | Notes | |-----|----------|----------|-------| | A | +28 VDC (Gyro motor) | 22 | Switched by gyro circuit breaker | | B | DC Ground | 22 | Return for gyro motor & electronics | | C | +28 VDC (Flight Director logic) | 24 | Optional, from FD computer | | D | Pitch command (analog ±6V) | 24 | Shield to pin E at source | | E | Pitch command return | 24 | Shield drain ground at computer | | F | Roll command (analog ±6V) | 24 | Shield to pin H at source | | H | Roll command return | 24 | Shield drain ground at computer | | J | Backlight Hi | 22 | 5V AC/DC max | | K | Backlight Lo | 22 | Return | | L | Instrument ground | 22 | Connect to avionics ground bus |
The final test must be performed by a qualified test pilot or an experienced technician . : If integrated with a test set like
: Confirm the aircraft instrument gauge indicates between 4.5 and 5.2 in. Hg at normal engine idle speeds.
: Confirm that the dash number matches the panel tilt angle of the target aircraft. Installing an 8-degree unit in a 0-degree panel causes persistent pitch bias during autopilot engagement. The electrical connector interfaces the unit with the
| Pin | Signal Name | Description | | :--- | :--- | :--- | | 1 | +28V DC (or +14V DC) | Power for the flight director command bar (and possibly pick‑off excitation) | | 2 | Ground (DC return) | Return for the power supply | | 3 | Pitch command input (+) | Flight director pitch steering signal from autopilot computer | | 4 | Pitch command input (−) | Return for pitch command | | 5 | Roll command input (+) | Flight director roll steering signal from autopilot computer | | 6 | Roll command input (−) | Return for roll command | | 7 | Pitch pick‑off output (sine) | AC signal proportional to pitch attitude → to autopilot computer | | 8 | Pitch pick‑off output (cosine) | Complementary pitch signal | | 9 | Roll pick‑off output (sine) | AC signal proportional to roll attitude → to autopilot computer | | 10 | Roll pick‑off output (cosine) | Complementary roll signal | | 11 | Pick‑off excitation (AC reference) | Typically 10 VAC, 400 Hz, supplied by autopilot computer | | 12 | Panel lighting (HOT) | 5 V or 14 V dimmed lighting bus | | 13 | Panel lighting (GROUND) | Lighting return | | 14-15 | Shield / Chassis Ground | For EMI protection |
: It is an air-driven gyro that provides pitch and roll attitude signals to the flight computer, such as the Digital Access Downloads & Manuals - Bendix/King
: Post-installation alignment involves placing the unit on a tilt stand and adjusting zero-adjust and gain-adjust potentiometers while monitoring voltages on specialized test sets like the Replacement Limitations
Internally air-driven, requiring a regulated vacuum source of 4.5 in. Hg . Mechanical Installation