GFC 500-style autopilot

The mode controller of a GFC 500-style autopilot: HDG knob, mode keys, the UP/DN wheel and the ALT SEL knob, driving the simulator's autopilot. A green bar on each key lights when its mode is active.

Modeled on: Garmin GFC 500-style autopilot (GMC 507 mode controller)
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

Keys: HDG, NAV, APR, AP, LVL (blue ring), FD, YD, IAS, VS, ALT; green bar lit when the mode is on (APR also while on the glideslope)
HDG knob sets the heading bug; push to sync to the current heading
ALT SEL knob sets the selected altitude; push to sync
Pitch wheel (DN / UP): vertical speed in VS, speed in IAS, else pitch
Fast knob turns take bigger steps (x10)
TRK and VNAV keys drawn, no simulator mode
At night the faceplate, keys and knobs take the red flood light while the display keeps its own colors, dimmed; the glareshield's warm light falls on the faceplate too when its dimmer is up (Settings > Dimmers > Glareshield, off by default)

On the iPad

Tap a mode key to toggle it
Drag around the HDG / TRK knob to move the heading bug; tap it to sync
Drag around the ALT SEL knob for the altitude; tap it to sync
Drag the wheel up or down (down = nose up / UP)

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 FD
Autopilot YD
Autopilot HDG
Autopilot NAV
Autopilot APR
Autopilot BC
Autopilot ALT
Autopilot VS
Autopilot FLC
Autopilot LVL
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`

Sends

When you…	MSFS	X-Plane
Any mode key (ApBit index)	`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`
Turning the HDG knob	`HEADING_BUG_SET`	`sim/cockpit2/autopilot/heading_dial_deg_mag_pilot`
Tapping the HDG knob; the Hub also sets the simulator's own directional gyro to the compass first (X-Plane DG_sync_mag, MSFS HEADING_GYRO_SET)	`HEADING_GYRO_SETHEADING_BUG_SET`	`sim/instruments/DG_sync_magsim/cockpit2/autopilot/heading_dial_deg_mag_pilot`
Turning the ALT SEL knob	`AP_ALT_VAR_SET_ENGLISH`	`sim/cockpit2/autopilot/altitude_dial_ft`
Tapping the ALT SEL knob	`AP_ALT_VAR_SET_ENGLISH`	`sim/cockpit2/autopilot/altitude_dial_ft`
Rolling the pitch wheel (+ nose up)	`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`