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NEXT avionics stack

NEXT avionics stack

A standing 2 x 3 rack of five units, as beside the NEXT navigator in a modern panel: audio panel, transponder, NAV/COM 1 and 2, and a GFC 500-style autopilot. Each unit is the full working module, sized to the rack's width so they line up as in a real stack.

Modeled on
Garmin GMA 350 / GTX 345 / GFC 500-style stack
Category
Avionics stacks
Size
2 × 3 cells
Version
1.0 · 2026-10-19
Plan
Pro
Simulators
MSFS 2020 · MSFS 2024 · X-Plane 11 · X-Plane 12

Variants

Unitsv1.0

Audio panel, transponder, NAV/COM 1, NAV/COM 2, autopilot (fixed order)

Fixed

Night lightingv1.0

Each unit lights its own parts: faceplates in the red flood light with their key and label printing backlit (Labels and keys dimmer) and the glareshield's warm light over them; displays keep their colors, dimmed (Displays dimmer), and go dark when the aircraft's avionics power is off

Panel lights: day / night / auto, and the lighting dimmers

Features

  • Five working units in one rack: GMA 350-style audio, GTX 345-style transponder, NAV/COM 1, NAV/COM 2, GFC 500-style autopilot
  • All units the same width, each at its faceplate's proportions, as in a real stack
  • Units fill the cell: each may be drawn up to 15% taller or shorter than its faceplate's proportions; any space left is spread evenly
  • Each unit lights itself at night: faceplate in the red flood with backlit keys and labels and the glareshield's light, displays dimmed (dark without avionics power)
  • Used by the 'Navigator + Avionics' view preset beside the NEXT navigator (glass-cockpit aircraft and jets)

On the iPad

  • Each unit works as it does on its own: its knobs, keys and displays (see audio panel, transponder, NAV/COM and autopilot entries)

Settings

  • None of its own: each unit keeps its own controls; panel lighting applies

Keys and controllers

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

  • Transmit on COM 1
  • Transmit on COM 2
  • Audio NAV 1
  • Audio NAV 2
  • Audio DME
  • Audio ADF
  • Audio MKR
  • COM 1 MHz +
  • COM 1 MHz -
  • COM 1 channel +
  • COM 1 channel -
  • COM 1 swap
  • NAV 1 MHz +
  • NAV 1 MHz -
  • NAV 1 channel +
  • NAV 1 channel -
  • NAV 1 swap
  • COM 2 MHz +
  • COM 2 MHz -
  • COM 2 channel +
  • COM 2 channel -
  • COM 2 swap
  • NAV 2 MHz +
  • NAV 2 MHz -
  • NAV 2 channel +
  • NAV 2 channel -
  • NAV 2 swap
  • Transponder IDENT
  • Transponder STBY
  • Transponder ALT
  • 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
  • CDI: next source

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

ValueMSFSX-Plane
Audio panel keys lit, one bit each (AudioBit: nav1, nav2, dme, adf, mkr, spkr) (bitfield)NAV SOUND:1 (bool)NAV SOUND:2 (bool)DME SOUND (bool)ADF SOUND:1 (bool)MARKER SOUND (bool)SPEAKER ACTIVE (bool)sim/cockpit2/radios/actuators/audio_selection_nav1sim/cockpit2/radios/actuators/audio_selection_nav2sim/cockpit2/radios/actuators/audio_dme_enabledsim/cockpit2/radios/actuators/audio_selection_adf1sim/cockpit2/radios/actuators/audio_marker_enabled
COM transmitting: 1, 2, 0 none (enum)COM TRANSMIT:1 (bool)COM TRANSMIT:2 (bool)sim/cockpit2/radios/actuators/audio_com_selection
COM1 heard (1/0) (bool)COM RECEIVE:1 (bool)sim/cockpit2/radios/actuators/audio_selection_com1
COM2 heard (1/0) (bool)COM RECEIVE:2 (bool)sim/cockpit2/radios/actuators/audio_selection_com2
Marker beacon: 0 none, 1 outer, 2 middle, 3 inner (enum)MARKER BEACON STATE (number)sim/cockpit2/radios/indicators/outer_marker_litsim/cockpit2/radios/indicators/middle_marker_litsim/cockpit2/radios/indicators/inner_marker_lit
Transponder code as its four digits (e.g. 1200) (code)TRANSPONDER CODE:1 (number)sim/cockpit2/radios/actuators/transponder_code
Transponder mode: 0 off, 1 standby, 2 test, 3 on, 4 altitude (enum)TRANSPONDER STATE:1 (number)sim/cockpit2/radios/actuators/transponder_mode
Outside air temperature (degC)AMBIENT TEMPERATURE (celsius)sim/cockpit2/temperature/outside_air_temp_degc
COM1 active frequency (kHz)COM ACTIVE FREQUENCY:1 (MHz)sim/cockpit2/radios/actuators/com1_frequency_hz_833
COM1 standby frequency (kHz)COM STANDBY FREQUENCY:1 (MHz)sim/cockpit2/radios/actuators/com1_standby_frequency_hz_833
COM2 active frequency (kHz)COM ACTIVE FREQUENCY:2 (MHz)sim/cockpit2/radios/actuators/com2_frequency_hz_833
COM2 standby frequency (kHz)COM STANDBY FREQUENCY:2 (MHz)sim/cockpit2/radios/actuators/com2_standby_frequency_hz_833
NAV1 active frequency (kHz)NAV ACTIVE FREQUENCY:1 (MHz)sim/cockpit2/radios/actuators/nav1_frequency_hz
NAV1 standby frequency (kHz)NAV STANDBY FREQUENCY:1 (MHz)sim/cockpit2/radios/actuators/nav1_standby_frequency_hz
NAV2 active frequency (kHz)NAV ACTIVE FREQUENCY:2 (MHz)sim/cockpit2/radios/actuators/nav2_frequency_hz
NAV2 standby frequency (kHz)NAV STANDBY FREQUENCY:2 (MHz)sim/cockpit2/radios/actuators/nav2_standby_frequency_hz
Text: station on COM1's active frequency (e.g. KSEA TWR) (text)COM ACTIVE FREQ IDENT:1COM ACTIVE FREQ TYPE:1Not available
Text: station on COM2's active frequency (text)COM ACTIVE FREQ IDENT:2COM ACTIVE FREQ TYPE:2Not available
Text: NAV1 station ident (e.g. SEA) (text)NAV IDENT:1Not available
Text: NAV2 station ident (text)NAV IDENT:2Not available
NAV1 receiver course deviation, + = course right (dots (-2.5..2.5))NAV CDI:1 (number)sim/cockpit2/radios/indicators/nav1_hdef_dots_pilot
NAV1 TO/FROM: 0 off, 1 TO, 2 FROM (enum)NAV TOFROM:1 (enum)sim/cockpit2/radios/indicators/nav1_flag_from_to_pilot
NAV1 receiving a station (1/0) (bool)NAV HAS NAV:1 (bool)sim/cockpit2/radios/indicators/nav1_flag_from_to_pilot
NAV1 OBS course (deg)NAV OBS:1 (degrees)sim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilot
NAV2 receiver course deviation, + = course right (dots (-2.5..2.5))NAV CDI:2 (number)sim/cockpit2/radios/indicators/nav2_hdef_dots_pilot
NAV2 TO/FROM: 0 off, 1 TO, 2 FROM (enum)NAV TOFROM:2 (enum)sim/cockpit2/radios/indicators/nav2_flag_from_to_pilot
NAV2 receiving a station (1/0) (bool)NAV HAS NAV:2 (bool)sim/cockpit2/radios/indicators/nav2_flag_from_to_pilot
NAV2 OBS course (deg)NAV OBS:2 (degrees)sim/cockpit2/radios/actuators/nav2_obs_deg_mag_pilot
NAV1 station has DME (1/0) (bool)NAV HAS DME:1 (bool)sim/cockpit2/radios/indicators/nav1_has_dme
NAV1 DME distance (nm)NAV DME:1 (nautical miles)NAV HAS DME:1 (bool)sim/cockpit2/radios/indicators/nav1_dme_distance_nmsim/cockpit2/radios/indicators/nav1_has_dme
NAV2 station has DME (1/0) (bool)NAV HAS DME:2 (bool)sim/cockpit2/radios/indicators/nav2_has_dme
NAV2 DME distance (nm)NAV DME:2 (nautical miles)NAV HAS DME:2 (bool)sim/cockpit2/radios/indicators/nav2_dme_distance_nmsim/cockpit2/radios/indicators/nav2_has_dme
The NAV source is a localizer (1/0) (bool)NAV HAS LOCALIZER:1 (bool)GPS DRIVES NAV1 (bool)sim/cockpit2/radios/actuators/nav1_frequency_hzsim/cockpit2/radios/actuators/HSI_source_select_pilot
CDI/HSI navigation source: 0 GPS, 1 NAV (enum)GPS DRIVES NAV1 (bool)sim/cockpit2/radios/actuators/HSI_source_select_pilot
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
Indicated altitude (ft)INDICATED ALTITUDE (feet)sim/cockpit2/gauges/indicators/altitude_ft_pilot
Selected altitude (ft)AUTOPILOT ALTITUDE LOCK VAR (feet)sim/cockpit2/autopilot/altitude_dial_ft
Selected airspeed (kt)AUTOPILOT AIRSPEED HOLD VAR (knots)sim/cockpit2/autopilot/airspeed_dial_kts_mach

Sends

When you…MSFSX-Plane
Audio panel: a COM MIC keyCOM1_TRANSMIT_SELECTCOM2_TRANSMIT_SELECTsim/cockpit2/radios/actuators/audio_com_selection (6 = COM1, 7 = COM2)
Audio panel: a COM receive keyCOM1_RECEIVE_SELECTCOM2_RECEIVE_SELECTsim/cockpit2/radios/actuators/audio_selection_com1sim/cockpit2/radios/actuators/audio_selection_com2
Audio panel: NAV / DME / ADF / MKR / SPKR keysRADIO_VOR1_IDENT_TOGGLERADIO_VOR2_IDENT_TOGGLERADIO_DME1_IDENT_TOGGLERADIO_ADF_IDENT_TOGGLEMARKER_SOUND_TOGGLETOGGLE_SPEAKERsim/cockpit2/radios/actuators/audio_selection_nav1sim/cockpit2/radios/actuators/audio_selection_nav2sim/cockpit2/radios/actuators/audio_dme_enabledsim/cockpit2/radios/actuators/audio_selection_adf1sim/cockpit2/radios/actuators/audio_marker_enabled
Transponder: a new code enteredXPNDR_SETsim/cockpit2/radios/actuators/transponder_code
Transponder: mode keysSimVar write: TRANSPONDER STATE:1sim/cockpit2/radios/actuators/transponder_mode
Transponder: IDENTXPNDR_IDENT_ONsim/transponder/transponder_ident
NAV/COM 1: COM knobs and swapCOM_STBY_RADIO_SET_HZCOM_STBY_RADIO_SWAPsim/cockpit2/radios/actuators/com1_standby_frequency_hz_833sim/radios/com1_standy_flip
NAV/COM 1: NAV knobs and swapNAV1_STBY_SET_HZNAV1_RADIO_SWAPsim/cockpit2/radios/actuators/nav1_standby_frequency_hzsim/radios/nav1_standy_flip
NAV/COM 2: COM knobs and swapCOM2_STBY_RADIO_SET_HZCOM2_RADIO_SWAPsim/cockpit2/radios/actuators/com2_standby_frequency_hz_833sim/radios/com2_standy_flip
NAV/COM 2: NAV knobs and swapNAV2_STBY_SET_HZNAV2_RADIO_SWAPsim/cockpit2/radios/actuators/nav2_standby_frequency_hzsim/radios/nav2_standy_flip
NAV/COM 1: the OBSVOR1_SETsim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (also, when HSI_source_select_pilot == 0)
NAV/COM 2: the OBSVOR2_SETsim/cockpit2/radios/actuators/nav2_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (also, when HSI_source_select_pilot == 1)
Autopilot: mode keysAP_MASTERTOGGLE_FLIGHT_DIRECTORYAW_DAMPER_TOGGLEAP_PANEL_HEADING_HOLDAP_NAV1_HOLDAP_APR_HOLDAP_BC_HOLDAP_ALT_HOLDAP_PANEL_VS_HOLDFLIGHT_LEVEL_CHANGEAP_WING_LEVELERsim/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
Autopilot: UP / DN wheelAP_VS_VAR_SET_ENGLISHAP_SPD_VAR_SETAP_PITCH_REF_INC_UPAP_PITCH_REF_INC_DNsim/cockpit2/autopilot/vvi_dial_fpmsim/cockpit2/autopilot/airspeed_dial_kts_machsim/autopilot/nose_upsim/autopilot/nose_down
Autopilot: heading knobHEADING_BUG_SETsim/cockpit2/autopilot/heading_dial_deg_mag_pilot
Autopilot: heading knob pushHEADING_GYRO_SETHEADING_BUG_SETsim/instruments/DG_sync_magsim/cockpit2/autopilot/heading_dial_deg_mag_pilot
Autopilot: altitude knobAP_ALT_VAR_SET_ENGLISHsim/cockpit2/autopilot/altitude_dial_ft
Autopilot: altitude knob pushAP_ALT_VAR_SET_ENGLISHsim/cockpit2/autopilot/altitude_dial_ft

Add-on aircraft with their own systems may use other variables; the Hub reads the standard ones.

Changes

The instrument's version counts what its faces share (the case, the mechanism, the data, the sounds); a face's own version counts that face alone.

  • 1.0 2026-10-19
    • First numbered version.
NEXT navigatorNEXT flight displayGMA 350-style audio panelGTX 345-style transponderNAV/COMGFC 500-style autopilotNAV/COM 1 + 2Classic avionics stack (KMA, KX, KT, KAP style)Free avionics rack