VOR / OBS

A VOR/ILS head with an OBS-turned azimuth card, a hinged CDI needle and glideslope needle, TO/FROM, and striped NAV and GS flags. Set it to NAV 1, NAV 2 or the GPS; the OBS knob sets that receiver's course in the simulator.

Modeled on: KI 209-style VOR/ILS indicator (square case)
Category: Flight instruments
Size: 1 cell
Version: 1.0 · 2026-10-19
Plan: Pro
Simulators: MSFS 2020 · MSFS 2024 · X-Plane 11 · X-Plane 12

Variants

NAV 1v1.0

NAV 1 course, needle, TO/FROM and glideslope; follows the GPS (labeled GPS in magenta) when the GPS drives the CDI.

Instrument picker > RECEIVER > NAV 1

NAV 2v1.0

NAV 2 OBS, needle and TO/FROM, labeled NAV 2; no glideslope.

RECEIVER > NAV 2

GPSv1.0

The GPS desired track and its deviation, labeled GPS; the GPS sets its own course (OBS knob inactive).

RECEIVER > GPS

Features

Azimuth card turned by the OBS under a lime course index
CDI needle hinged at the top and glideslope needle hinged at the left, swinging as on the real one (5 dots each side)
TO / FROM triangle window
Red-and-white striped NAV flag without a station and GS flag without a glideslope
Receiver label (GPS / NAV 2) on the face when not plain NAV 1
Red X when the selected receiver's course is missing
Power-on self-test when the aircraft's avionics come on (about 3.6 s): the CDI swings full left and right, then the glideslope needle full up and down, the flags pull out (TO, then FROM) and drop back, then it reads its receiver
Night lighting: the face takes the panel's red flood light, the glareshield's warm light from above (stronger for instruments higher on the page) and its own light, a lamp hidden at the top of the case lighting the dial downward (Settings > Dimmers: Red flood light, Glareshield, Instruments (analog))

On the iPad

Drag the OBS knob (lower left) up or down to turn the course; double tap it to center the needle (course to the station)
On the GPS receiver the knob does nothing
Tap elsewhere on the face to change the instrument

Settings

Receiver: NAV 1 / NAV 2 / GPS (instrument picker)

Keys and controllers

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

Course +
Course -
Course sync
NAV 2 course +
NAV 2 course -
NAV 2 course 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
Course shown on the HSI (deg)	`GPS WP DESIRED TRACK (degrees)NAV OBS:1 (degrees)GPS DRIVES NAV1 (bool)`	`sim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot`
Course deviation, + = course to the right (dots (-2.5..2.5))	`HSI CDI NEEDLE (number)`	`sim/cockpit2/radios/indicators/hsi_hdef_dots_pilot`
TO/FROM flag: 0 off, 1 TO, 2 FROM (enum)	`HSI TF FLAGS (enum)`	`sim/cockpit2/radios/indicators/hsi_flag_from_to_pilot`
CDI needle valid (1/0) (bool)	`HSI CDI NEEDLE VALID (bool)`	`sim/cockpit2/radios/indicators/hsi_flag_from_to_pilot`
Glideslope valid (1/0) (bool)	`HSI GSI NEEDLE VALID (bool)`	`sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot`
Glideslope deviation (dots)	`HSI GSI NEEDLE (number)`	`sim/cockpit2/radios/indicators/hsi_vdef_dots_pilot`
Distance to the station / waypoint (HSI) (nm)	`HSI DISTANCE (nautical miles)`	`sim/cockpit2/radios/indicators/hsi_dme_distance_nm_pilot`
CDI/HSI navigation source: 0 GPS, 1 NAV (enum)	`GPS DRIVES NAV1 (bool)`	`sim/cockpit2/radios/actuators/HSI_source_select_pilot`
NAV2 OBS course (deg)	`NAV OBS:2 (degrees)`	`sim/cockpit2/radios/actuators/nav2_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 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`
GPS desired track (deg)	`GPS WP DESIRED TRACK (degrees)GPS IS ACTIVE FLIGHT PLAN (bool)`	Not available
GPS's own course deviation (dots)	`GPS CDI NEEDLE (number)`	`sim/cockpit2/radios/indicators/gps_hdef_dots_pilot`
GPS flight plan active (1/0) (bool)	`GPS IS ACTIVE FLIGHT PLAN (bool)`	Not available
Distance to the active waypoint (nm)	`GPS WP DISTANCE (nautical miles)GPS IS ACTIVE FLIGHT PLAN (bool)`	Not available

Sends

When you…	MSFS	X-Plane
Dragging the OBS knob on NAV 1, or mapped 'Course +' / '-'	`VOR1_SET`	`sim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (also, when HSI_source_select_pilot == 0)`
Double tap on the OBS knob on NAV 1, or mapped 'Course sync'	`VOR1_SET`	`sim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (when HSI shows NAV1)`
Dragging the OBS knob on NAV 2, or mapped 'NAV 2 course +' / '-'	`VOR2_SET`	`sim/cockpit2/radios/actuators/nav2_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (also, when HSI_source_select_pilot == 1)`
Double tap on the OBS knob on NAV 2, or mapped 'NAV 2 course sync'	`VOR2_SET`	`sim/cockpit2/radios/actuators/nav2_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (when HSI shows NAV2)`