KAP 140-style autopilot

A classic Bendix/King-style autopilot with an orange gas-discharge display: AP, HDG, NAV, APR, REV, ALT, UP / DN for the vertical speed, and the altitude knob. The display shows the lateral and vertical modes and the VS or the selected altitude.

Modeled on: Bendix/King KAP 140-style autopilot
Category: Autopilots
Size: 2 × 1 cells
Version: 1.0 · 2026-10-19
Plan: Pro
Simulators: MSFS 2020 · MSFS 2024 · X-Plane 11 · X-Plane 12

Features

Display: AP when engaged, lateral mode (ROL, HDG, NAV, APR, REV), vertical mode (VS, ALT, GS)
In VS: the target vertical speed in FPM; otherwise the selected altitude in FT
With the autopilot off: only the selected altitude
UP / DN keys step the vertical speed
Dual altitude knob: outer 10 steps, inner 1; tap to sync
ARM and BARO keys drawn, no simulator effect
Gas-discharge digits dimmed at night; dark without avionics power; the faceplate takes the red flood light and, when its dimmer is up, the glareshield's warm light (Settings > Dimmers > Glareshield, off by default)

On the iPad

Tap AP, HDG, NAV, APR, REV, ALT
Tap UP / DN to change the vertical speed
Drag the altitude knob (outside ring for big steps, middle for small); tap it to sync

Keys and controllers

Map any of these to a key, a game controller's button or axis, or a MIDI knob (how):

Autopilot AP
Autopilot HDG
Autopilot NAV
Autopilot APR
Autopilot BC
Autopilot ALT
Autopilot VS
Autopilot UP / DN +
Autopilot UP / DN -
Altitude +
Altitude -
Altitude sync

Simulator data

What the Hub reads from the simulator for this instrument, and what the instrument sends back. Names are the simulators' own: MSFS SimVars and events, X-Plane datarefs and commands.

Reads

Value	MSFS	X-Plane
Autopilot modes, one bit each (ApBit: ap, fd, yd, hdg, nav, apr, bc, alt, vs, flc, lvl, gs, vnv) (bitfield)	`AUTOPILOT MASTER (bool)AUTOPILOT FLIGHT DIRECTOR ACTIVE (bool)AUTOPILOT YAW DAMPER (bool)AUTOPILOT HEADING LOCK (bool)AUTOPILOT NAV1 LOCK (bool)AUTOPILOT APPROACH HOLD (bool)AUTOPILOT BACKCOURSE HOLD (bool)AUTOPILOT ALTITUDE LOCK (bool)AUTOPILOT VERTICAL HOLD (bool)AUTOPILOT FLIGHT LEVEL CHANGE (bool)AUTOPILOT WING LEVELER (bool)AUTOPILOT GLIDESLOPE HOLD (bool)`	`sim/cockpit2/autopilot/servos_onsim/cockpit2/autopilot/flight_director_modesim/cockpit2/switches/yaw_damper_onsim/cockpit2/autopilot/heading_statussim/cockpit2/autopilot/nav_statussim/cockpit2/autopilot/approach_statussim/cockpit2/autopilot/backcourse_statussim/cockpit2/autopilot/altitude_hold_statussim/cockpit2/autopilot/vvi_statussim/cockpit2/autopilot/speed_statussim/cockpit2/autopilot/roll_statussim/cockpit2/autopilot/glideslope_status`
Autopilot vertical speed target (fpm)	`AUTOPILOT VERTICAL HOLD VAR (feet per minute)`	`sim/cockpit2/autopilot/vvi_dial_fpm`
Selected altitude (ft)	`AUTOPILOT ALTITUDE LOCK VAR (feet)`	`sim/cockpit2/autopilot/altitude_dial_ft`

Sends

When you…	MSFS	X-Plane
AP, HDG, NAV, APR, REV (BC), ALT keys	`AP_MASTERTOGGLE_FLIGHT_DIRECTORYAW_DAMPER_TOGGLEAP_PANEL_HEADING_HOLDAP_NAV1_HOLDAP_APR_HOLDAP_BC_HOLDAP_ALT_HOLDAP_PANEL_VS_HOLDFLIGHT_LEVEL_CHANGEAP_WING_LEVELER`	`sim/autopilot/servos_togglesim/autopilot/fdir_togglesim/systems/yaw_damper_togglesim/autopilot/headingsim/autopilot/NAVsim/autopilot/approachsim/autopilot/back_coursesim/autopilot/altitude_holdsim/autopilot/vertical_speedsim/autopilot/level_changesim/autopilot/wing_leveler`
UP (+1) / DN (-1) keys	`AP_VS_VAR_SET_ENGLISHAP_SPD_VAR_SETAP_PITCH_REF_INC_UPAP_PITCH_REF_INC_DN`	`sim/cockpit2/autopilot/vvi_dial_fpmsim/cockpit2/autopilot/airspeed_dial_kts_machsim/autopilot/nose_upsim/autopilot/nose_down`
Turning the altitude knob (outer x10 + inner)	`AP_ALT_VAR_SET_ENGLISH`	`sim/cockpit2/autopilot/altitude_dial_ft`
Tapping the altitude knob	`AP_ALT_VAR_SET_ENGLISH`	`sim/cockpit2/autopilot/altitude_dial_ft`