diff --git a/Scripts/DCS-BIOS/BIOS.lua b/Scripts/DCS-BIOS/BIOS.lua
index 936ce01d8..5d1cc5bd9 100644
--- a/Scripts/DCS-BIOS/BIOS.lua
+++ b/Scripts/DCS-BIOS/BIOS.lua
@@ -87,7 +87,9 @@ dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\P-47D.lua]]) -- ID = 34, ProperNam
 local P_51D = require "P-51D"
 BIOS.protocol.writeNewModule(P_51D)
 dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\SA342.lua]]) -- ID = 36, ProperName = SA342 Gazelle
-dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\SpitfireLFMkIX.lua]]) -- ID = 37, ProperName = Spitfire LF Mk. IX
+-- dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\SpitfireLFMkIX.lua]]) -- ID = 37, ProperName = Spitfire LF Mk. IX
+local SpitfireLFMkIX = require "SpitfireLFMkIX"
+BIOS.protocol.writeNewModule(SpitfireLFMkIX)
 --dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\SuperCarrier.lua]])
 dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\UH-1H.lua]]) -- ID = 38, ProperName = UH-1H Huey
 dofile(lfs.writedir()..[[Scripts\DCS-BIOS\lib\VNAO_Room.lua]])
diff --git a/Scripts/DCS-BIOS/lib/modules/Module.lua b/Scripts/DCS-BIOS/lib/modules/Module.lua
index 51609d188..9d6dbc124 100644
--- a/Scripts/DCS-BIOS/lib/modules/Module.lua
+++ b/Scripts/DCS-BIOS/lib/modules/Module.lua
@@ -504,6 +504,55 @@ function Module:defineTumb(identifier, device_id, command, arg_number, step, lim
 	return control
 end
 
+--- Adds a 3-position switch with a spring-loaded return
+--- @param identifier string the unique identifier for the control
+--- @param device_id integer the dcs device id
+--- @param down_switch integer the dcs command to move the switch down
+--- @param up_switch integer the dcs command to move the switch up
+--- @param arg_number integer the dcs argument number
+--- @param category string the category in which the control should appear
+--- @param description string additional information about the control
+--- @return Control control the control which was added to the module
+function Module:defineSpringloaded_3PosTumb(identifier, device_id, down_switch, up_switch, arg_number, category, description)
+	local alloc = self:allocateInt(2)
+	self:addExportHook(function(dev0)
+		local val = dev0:get_argument_value(arg_number)
+		if val == -1 then
+			alloc:setValue(0)
+		elseif val == 0 then
+			alloc:setValue(1)
+		elseif val == 1 then
+			alloc:setValue(2)
+		end
+	end)
+
+	local control = Control:new(category, ControlType.three_pos_two_command_switch_open_close, identifier, description, {
+		SetStateInput:new(2, "set the switch position"),
+	}, {
+		IntegerOutput:new(alloc, Suffix.none, "switch position -- 0 = Down, 1 = Mid,  2 = Up"),
+	})
+
+	self:addControl(control)
+
+	self:addInputProcessor(identifier, function(toState)
+		local dev = GetDevice(device_id)
+		if toState == "0" then --downSwitch
+			dev:performClickableAction(down_switch, 0)
+			dev:performClickableAction(up_switch, 0)
+			dev:performClickableAction(down_switch, -1)
+		elseif toState == "1" then --Stop
+			dev:performClickableAction(down_switch, 0)
+			dev:performClickableAction(up_switch, 0)
+		elseif toState == "2" then --upSwitch
+			dev:performClickableAction(down_switch, 0)
+			dev:performClickableAction(up_switch, 0)
+			dev:performClickableAction(up_switch, 1)
+		end
+	end)
+
+	return control
+end
+
 --- Allocates space for a string to the memory map of the module
 --- @param max_length integer the maximum length of the string
 --- @return StringAllocation alloc the space allocated for the string
diff --git a/Scripts/DCS-BIOS/lib/modules/aircraft_modules/SpitfireLFMkIX.lua b/Scripts/DCS-BIOS/lib/modules/aircraft_modules/SpitfireLFMkIX.lua
new file mode 100644
index 000000000..e563e2245
--- /dev/null
+++ b/Scripts/DCS-BIOS/lib/modules/aircraft_modules/SpitfireLFMkIX.lua
@@ -0,0 +1,167 @@
+module("SpitfireLFMkIX", package.seeall)
+
+local Module = require("Module")
+
+--- @class SpitfireLFMkIX: Module
+local SpitfireLFMkIX = Module:new("SpitfireLFMkIX", 0x5400, { "SpitfireLFMkIX", "SpitfireLFMkIXCW" })
+-- remove Arg# Pilot 165
+
+--Oxygen Apparatus Controls
+SpitfireLFMkIX:defineToggleSwitch("OXY_VALVE", 3, 3003, 13, "Cockpit", "Oxygen Valve")
+SpitfireLFMkIX:defineToggleSwitch("SAFETY", 5, 3001, 3, "Weapons", "Safety Lever")
+SpitfireLFMkIX:definePushButton("BUTTON_MG", 5, 3003, 4, "Weapons", "MG Trigger")
+SpitfireLFMkIX:definePushButton("BUTTON_CAN", 5, 3004, 5, "Weapons", "Cannons Trigger")
+SpitfireLFMkIX:definePushButton("BUTTON_LINKED", 5, 3005, 6, "Weapons", "MG+Cannons Trigger")
+SpitfireLFMkIX:definePotentiometer("WHEEL_BRAKES", 1, 3002, 9, { 0, 1 }, "Undercarriage", "Wheel Brakes Lever")
+
+-- Main Panel
+SpitfireLFMkIX:defineRotary("ALT_MBAR", 1, 3037, 30, "Cockpit", "Altimeter Pressure Set")
+SpitfireLFMkIX:defineRotary("DI", 1, 3041, 32, "Cockpit", "Directional Gyro Adjust")
+SpitfireLFMkIX:definePushButton("FUEL_GAUGE", 1, 3005, 44, "Cockpit", "Show Fuel Contents")
+SpitfireLFMkIX:defineToggleSwitch("NAV_LIGHTS", 1, 3007, 46, "Lights", "Nav. Lights On/Off")
+SpitfireLFMkIX:defineToggleSwitch("FLAPS", 1, 3009, 47, "Cockpit", "Landing Flaps Up/Down")
+SpitfireLFMkIX:defineToggleSwitch("UC_BLIND", 1, 3011, 50, "Cockpit", "U/C Indicator Blind Up/Down")
+SpitfireLFMkIX:definePushButton("CLK_PINION_PULL", 17, 3006, 54, "Cockpit", "Winding/Adjustment Clock Pull out.")
+SpitfireLFMkIX:defineRotary("CLK_PINION", 17, 3004, 55, "Cockpit", "Winding/Adjustment Clock")
+SpitfireLFMkIX:defineToggleSwitch("MAGNETO0", 2, 3015, 56, "Engine", "No. 1 Magneto On/Off")
+SpitfireLFMkIX:defineToggleSwitch("MAGNETO1", 2, 3017, 57, "Engine", "No. 2 Magneto On/Off")
+SpitfireLFMkIX:defineToggleSwitch("BLOWER", 2, 3019, 58, "Engine", "Supercharger Mode Auto/M.S.")
+SpitfireLFMkIX:definePotentiometer("PITLITE_LH", 4, 3001, 60, { 0, 1 }, "Lights", "Port Flood Lamp Brightness")
+SpitfireLFMkIX:definePotentiometer("PITLITE_RH", 4, 3004, 61, { 0, 1 }, "Lights", "Stbd. Flood Lamp Brightness")
+SpitfireLFMkIX:defineToggleSwitch("STARTER_COVER", 2, 3021, 64, "Engine", "Starter Button Cover")
+SpitfireLFMkIX:definePushButton("STARTER", 2, 3023, 65, "Engine", "Starter")
+SpitfireLFMkIX:defineToggleSwitch("BOOSTER_COVER", 2, 3025, 66, "Engine", "Booster Coil Button Cover")
+SpitfireLFMkIX:definePushButton("BOOSTER", 2, 3027, 67, "Engine", "Booster Coil")
+SpitfireLFMkIX:definePotentiometer("PRIMER_TURN", 2, 3029, 68, { 0, 1 }, "Engine", "Primer Pump Turn")
+SpitfireLFMkIX:definePushButton("PRIMER_PULL", 2, 3030, 69, "Engine", "Primer Pump Pull")
+SpitfireLFMkIX:defineToggleSwitch("TANK_PRS", 2, 3033, 70, "Engine", "Fuel Tank Pressure On/Off")
+SpitfireLFMkIX:defineFixedStepTumb("COMPASS_RING", 1, 3017, 74, 0.00333, { 0, 1 }, { -0.00333, 0.00333 }, nil, "Cockpit", "Compass Course Setter Ring")
+
+-- Gun Sight and Tertiary Weapons Controls
+SpitfireLFMkIX:definePotentiometer("GUNSIGHT_RANGE", 5, 3007, 77, { 0, 1 }, "Weapons", "Gunsight Range")
+SpitfireLFMkIX:definePotentiometer("GUNSIGHT_BASE", 5, 3010, 78, { 0, 1 }, "Weapons", "Gunsight Base")
+SpitfireLFMkIX:defineToggleSwitch("GUNSIGHT_TINT", 5, 3016, 79, "Weapons", "Gunsight Tint Screen Up/Down")
+SpitfireLFMkIX:defineToggleSwitch("GUNSIGHT_SWITCH", 5, 3018, 80, "Weapons", "Gunsight Master On/Off")
+SpitfireLFMkIX:definePotentiometer("GUNSIGHT_DIMMER", 5, 3020, 81, { 0, 1 }, "Weapons", "Gun Sight Light")
+
+-- Port Wall
+SpitfireLFMkIX:definePotentiometer("TRIM_WHEEL", 1, 3029, 145, { -1, 1 }, "Controls", "Elevator Trim")
+SpitfireLFMkIX:definePotentiometer("RTRIM_WHEEL", 1, 3044, 146, { -1, 1 }, "Controls", "Rudder Trim")
+
+-- Radio Remote Channel Switcher
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_OFF", 15, 3001, 115, "Radio", "Radio Power OFF")
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_A", 15, 3002, 116, "Radio", "Radio Channel A")
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_B", 15, 3003, 117, "Radio", "Radio Channel B")
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_C", 15, 3004, 118, "Radio", "Radio Channel C")
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_D", 15, 3005, 119, "Radio", "Radio Channel D")
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_DIM", 15, 3006, 125, "Radio", "Radio Channel Dimmer")
+SpitfireLFMkIX:defineToggleSwitch("RCTRL_TLOCK", 15, 3017, 155, "Radio", "Switch Locking Lever")
+SpitfireLFMkIX:defineSpringloaded_3PosTumb("RCTRL_T_MODE", 15, 3008, 3007, 156, "Radio", "Radio Mode Switch")
+
+-- Throttle Quadrant
+SpitfireLFMkIX:definePushButton("BUTTON_BOMB", 5, 3015, 128, "Weapons", "Drop Bombs")
+SpitfireLFMkIX:definePotentiometer("PROP", 2, 3006, 129, { -1, 1 }, "Engine", "Propeller RPM")
+SpitfireLFMkIX:defineToggleSwitch("MIX", 2, 3009, 130, "Engine", "Mixture Control Select IDLE CUT OFF/RUN")
+SpitfireLFMkIX:defineToggleSwitch("UC_DOWN_C", 2, 3099, 131, "Undercarriage", "U/C Indicator Cut-Off On/Off")
+SpitfireLFMkIX:defineToggleSwitch("RADIATOR", 1, 3033, 133, "Engine", "Radiator Flap Open/Auto")
+SpitfireLFMkIX:defineToggleSwitch("PITOT", 1, 3035, 134, "Engine", "Pitot Heating On/Off")
+SpitfireLFMkIX:defineToggleSwitch("FUEL_PUMP", 2, 3043, 135, "Engine", "Fuel Pump On/Off")
+SpitfireLFMkIX:defineToggleSwitch("CARB_AIR", 2, 3045, 137, "Engine", "Carburettor Air Control")
+SpitfireLFMkIX:defineToggleSwitch("DILUTER_COVER", 2, 3051, 157, "Engine", "Oil Dilution Button Cover")
+SpitfireLFMkIX:definePushButton("DILUTER", 2, 3053, 158, "Engine", "Oil Dilution")
+SpitfireLFMkIX:defineToggleSwitch("MS_TEST_COVER", 2, 3055, 159, "Engine", "Supercharger Test Button Cover")
+SpitfireLFMkIX:definePushButton("MS_TEST", 2, 3057, 160, "Engine", "Supercharger Test")
+SpitfireLFMkIX:defineToggleSwitch("RAD_TEST_COVER", 2, 3059, 161, "Engine", "Radiator Test Button Cover")
+SpitfireLFMkIX:definePushButton("RAD_TEST", 2, 3061, 162, "Engine", "Radiator Test")
+
+-- Stbd. Wall
+SpitfireLFMkIX:defineToggleSwitch("DEICER", 1, 3021, 87, "Cockpit", "Windscreen De-Ice On/Off")
+SpitfireLFMkIX:defineToggleSwitch("UC_EMER", 1, 3023, 88, "Undercarriage", "Undercarriage Emergency Release")
+SpitfireLFMkIX:defineToggleSwitch("WOBBLE_PUMP", 2, 3035, 90, "Engine", "Wobble Type Fuel Pump")
+SpitfireLFMkIX:defineToggleSwitch("UC", 1, 3025, 148, "Undercarriage", "Undercarriage Raise/Lower")
+
+-- Morse Key & Apparatus
+SpitfireLFMkIX:defineTumb("MORSE_UP_MODE", 4, 3007, 92, 0.5, { 0, 1 }, nil, false, "Lights", "Upward Lamp Mode")
+SpitfireLFMkIX:defineTumb("MORSE_DN_MODE", 4, 3011, 93, 0.5, { 0, 1 }, nil, false, "Lights", "Downward Lamp Mode")
+SpitfireLFMkIX:definePushButton("MORSE_KEY", 4, 3015, 94, "Lights", "Morse Key")
+
+-- I.F.F. Control Box
+SpitfireLFMkIX:defineToggleSwitch("IFF_B", 4, 3017, 106, "Radio", "I.F.F. Circuit B")
+SpitfireLFMkIX:defineToggleSwitch("IFF_D", 4, 3019, 107, "Radio", "I.F.F. Circuit D")
+SpitfireLFMkIX:defineToggleSwitch("IFF_COVER", 4, 3021, 108, "Radio", "I.F.F. Cover Open/Close")
+SpitfireLFMkIX:definePushButton("IFF_0", 4, 3023, 109, "Radio", "I.F.F. Detonate Button 1")
+SpitfireLFMkIX:definePushButton("IFF_1", 4, 3025, 110, "Radio", "I.F.F. Detonate Button 2")
+
+-- Fuel Cocks & Tertiary
+SpitfireLFMkIX:defineToggleSwitch("FUEL_COCK", 2, 3037, 100, "Engine", "Main Tank On/Off")
+SpitfireLFMkIX:defineToggleSwitch("DROPTANK_COCK", 2, 3041, 98, "Engine", "Drop Tank On/Off")
+SpitfireLFMkIX:defineToggleSwitch("DROPTANK_JETT", 5, 3013, 99, "Engine", "Drop Tank Release Handle")
+
+-- Canopy Controls
+SpitfireLFMkIX:defineToggleSwitch("HATCH", 1, 3051, 149, "Cockpit", "Canopy Open/Close Control")
+SpitfireLFMkIX:defineToggleSwitch("HATCH_JETTISON", 1, 3057, 140, "Cockpit", "Jettison Canopy Pull Ball")
+SpitfireLFMkIX:defineToggleSwitch("SIDE_DOOR", 1, 3059, 147, "Cockpit", "Side Door Open/Close Control")
+
+-- Indicators
+SpitfireLFMkIX:defineFloat("CANOPY_TRUCKS", 162, { 0, 1 }, "Indicator", "Canopy Trucks") --not Working
+SpitfireLFMkIX:defineFloat("CANOPY_VISIBILITY", 163, { 0, 1 }, "Indicator", "Canopy Visibility") --not Working
+SpitfireLFMkIX:defineFloat("CANOPY_CRANK", 147, { 0, 1 }, "Indicator", "Canopy Crank") --not Working
+SpitfireLFMkIX:defineFloat("OXYGENDELIVERYGAUGE", 11, { 0, 0.4 }, "Indicator", "Oxygen Delivery Gauge")
+SpitfireLFMkIX:defineFloat("OXYGENSUPPLYGAUGE", 12, { 0, 1 }, "Indicator", "Oxygen Supply Gauge")
+SpitfireLFMkIX:defineFloat("TRIMGAUGE", 17, { -1, 1 }, "Indicator", "Trim Gauge")
+SpitfireLFMkIX:defineFloat("PNEUMATICPRESSUREGAUGE", 18, { 0, 1 }, "Indicator", "PneumaticPressureGauge")
+SpitfireLFMkIX:defineFloat("LEFTWHEELBRAKEGAUGE", 19, { 0, 1 }, "Indicator", "Left Wheel Brake Gauge")
+SpitfireLFMkIX:defineFloat("RIGHTWHEELBRAKEGAUGE", 20, { 0, 1 }, "Indicator", "Right Wheel Brake Gauge")
+SpitfireLFMkIX:defineFloat("AIRSPEEDGAUGE", 21, { 0.0, 0.5 }, "Indicator", "Airspeed Gauge")
+SpitfireLFMkIX:defineFloat("AHORIZONBANK", 23, { -1, 1 }, "Indicator", "AHorizon Bank")
+SpitfireLFMkIX:defineFloat("AHORIZONPITCH", 24, { -1, 1 }, "Indicator", "AHorizon Pitch")
+SpitfireLFMkIX:defineFloat("VARIOMETERGAUGE", 25, { -1, 1 }, "Indicator", "Variometer Gauge")
+SpitfireLFMkIX:defineFloat("ALTIMETERHUNDREDS", 26, { 0, 1 }, "Indicator", "Altimeter 100")
+SpitfireLFMkIX:defineFloat("ALTIMETERTHOUSANDS", 27, { 0, 1 }, "Indicator", "Altimeter 1000")
+SpitfireLFMkIX:defineFloat("ALTIMETERTENSTHOUSANDS", 28, { 0, 1 }, "Indicator", "Altimeter 10000")
+SpitfireLFMkIX:defineFloat("ALTIMETERSETPRESSURE", 29, { 0, 1 }, "Indicator", "Altimeter Set Pressure")
+SpitfireLFMkIX:defineFloat("DIGAUGE", 31, { 0, 1 }, "Indicator", "DI Gauge")
+SpitfireLFMkIX:defineFloat("SIDESLIPGAUGE", 33, { -1, 1 }, "Indicator", "Sideslip Gauge")
+SpitfireLFMkIX:defineFloat("TURNGAUGE", 34, { -1, 1 }, "Indicator", "Turn Gauge")
+SpitfireLFMkIX:defineFloat("VOLTMETERGAUGE", 35, { 0, 1 }, "Indicator", "Voltmeter Gauge")
+SpitfireLFMkIX:defineFloat("TACHOMETERGAUGE", 37, { 0.0, 0.5 }, "Indicator", "Tachometer Gauge")
+SpitfireLFMkIX:defineFloat("BOOSTGAUGE", 39, { 0, 1 }, "Indicator", "Boost Gauge")
+SpitfireLFMkIX:defineFloat("OILPRESSUREGAUGE", 40, { 0, 1 }, "Indicator", "Oil Pressure Gauge")
+SpitfireLFMkIX:defineFloat("OILTEMPERATUREGAUGE", 41, { 0, 1 }, "Indicator", "Oil Temperature Gauge")
+SpitfireLFMkIX:defineFloat("RADIATORTEMPERATUREGAUGE", 42, { 0, 0.7 }, "Indicator", "Radiator Temperature Gauge")
+SpitfireLFMkIX:defineFloat("FUELRESERVEGAUGE", 43, { 0, 1 }, "Indicator", "Fuel Reserve Gauge")
+
+-- Warning, Caution and IndicatorLights
+SpitfireLFMkIX:defineIndicatorLight("FUEL_PRESS_LIGHT", 45, "Warning, Caution and IndicatorLights", "Fuel Pressure Warning Light (red)")
+SpitfireLFMkIX:defineIndicatorLight("GEAR_UP", 48, "Warning, Caution and IndicatorLights", "Gear UP Lamp (red)")
+SpitfireLFMkIX:defineIndicatorLight("GEAR_DOWN", 49, "Warning, Caution and IndicatorLights", "Gear DOWN Lamp (green)")
+SpitfireLFMkIX:defineIndicatorLight("CHARGER_SEC_GEAR_LIGHT", 59, "Warning, Caution and IndicatorLights", "Supercharger Second Gear Warning Light (yellow)")
+SpitfireLFMkIX:defineIndicatorLight("CONSOLE_R_LIGHT", 62, "Warning, Caution and IndicatorLights", "Right Console Light (red)")
+SpitfireLFMkIX:defineIndicatorLight("CONSOLE_L_LIGHT", 63, "Warning, Caution and IndicatorLights", "Left Console Light (red)")
+SpitfireLFMkIX:defineIndicatorLight("PANEL_BACKLIGHT", 163, "Warning, Caution and IndicatorLights", "Main Panel Backlight (white)")
+
+--Externals
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_POSITION_LIGHT_LEFT", 190, "External Aircraft Model", "Left Position Light (red)")
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_POSITION_LIGHT_RIGHT", 191, "External Aircraft Model", "Right Position Light (green)")
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_POSITION_LIGHT_TAIL", 192, "External Aircraft Model", "Tail Position Light (White)")
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_POSITION_LIGHT_TOP", 193, "External Aircraft Model", "Top Position Light (White)")
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_POSITION_LIGHT_BOTTOM", 194, "External Aircraft Model", "Bottom Position Light (White)")
+
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_WOW_TAIL", 1, "External Aircraft Model", "Weight ON Wheels Tail Gear")
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_WOW_RIGHT", 4, "External Aircraft Model", "Weight ON Wheels Right Gear")
+SpitfireLFMkIX:defineBitFromDrawArgument("EXT_WOW_LEFT", 6, "External Aircraft Model", "Weight ON Wheels Left Gear")
+
+SpitfireLFMkIX:defineFloat("CANOPY_POS", 138, { 0, 1 }, "Indicator", "Canopy Position")
+SpitfireLFMkIX:defineFloat("PANEL_SHAKE_Z", 142, { -0.8, 0.8 }, "Indicator", "Common Panel Shaker (Z Axis)")
+SpitfireLFMkIX:defineFloat("PANEL_SHAKE_Y", 143, { -0.8, 0.8 }, "Indicator", "Common Panel Shaker (Y Axis)")
+SpitfireLFMkIX:defineFloat("PANEL_SHAKE_X", 144, { -0.8, 0.8 }, "Indicator", "Common Panel Shaker (X Axis)")
+SpitfireLFMkIX:defineFloat("COMPASS_PITCH", 71, { -1, 1 }, "Indicator", "Compass Pitch")
+SpitfireLFMkIX:defineFloat("COMPASS_BANK", 72, { -1, 1 }, "Indicator", "Compass Bank")
+SpitfireLFMkIX:defineFloat("COMPASS_HDG", 73, { -1, 1 }, "Indicator", "Compass Heading")
+SpitfireLFMkIX:defineIndicatorLight("RADIO_A_LIGHT", 120, "Radio Lights", "Radio A Light (white)")
+SpitfireLFMkIX:defineIndicatorLight("RADIO_B_LIGHT", 121, "Radio Lights", "Radio B Light (white)")
+SpitfireLFMkIX:defineIndicatorLight("RADIO_C_LIGHT", 122, "Radio Lights", "Radio C Light (white)")
+SpitfireLFMkIX:defineIndicatorLight("RADIO_D_LIGHT", 123, "Radio Lights", "Radio D Light (white)")
+SpitfireLFMkIX:defineIndicatorLight("RADIO_TX_LIGHT", 124, "Radio Lights", "Radio TX Light (white)")
+
+return SpitfireLFMkIX
diff --git a/Scripts/DCS-BIOS/test/AircraftTest.lua b/Scripts/DCS-BIOS/test/AircraftTest.lua
index 408ce1402..ea922c67c 100644
--- a/Scripts/DCS-BIOS/test/AircraftTest.lua
+++ b/Scripts/DCS-BIOS/test/AircraftTest.lua
@@ -15,6 +15,10 @@ function TestAircraft:testP51D()
 	self:validateModule(require("P-51D"), "P-51D", 0x5000)
 end
 
+function TestAircraft:testSpitfireLFMkIX()
+	self:validateModule(require("SpitfireLFMkIX"), "SpitfireLFMkIX", 0x5400)
+end
+
 --- Validates a module is as expected and that control names are valid
 --- @param module Module
 --- @param expected_name string
diff --git a/Scripts/DCS-BIOS/test/ModuleTest.lua b/Scripts/DCS-BIOS/test/ModuleTest.lua
index 0972907d5..6f0a1577b 100644
--- a/Scripts/DCS-BIOS/test/ModuleTest.lua
+++ b/Scripts/DCS-BIOS/test/ModuleTest.lua
@@ -48,3 +48,4 @@ require("BitFromDrawArgumentTest")
 require("FloatFromDrawArgumentTest")
 require("IntegerFromGetterTest")
 require("TumbTest")
+require("SpringLoadedThreePosTumbTest")
diff --git a/Scripts/DCS-BIOS/test/controls/SpringLoadedThreePosTumbTest.lua b/Scripts/DCS-BIOS/test/controls/SpringLoadedThreePosTumbTest.lua
new file mode 100644
index 000000000..605fcdfa7
--- /dev/null
+++ b/Scripts/DCS-BIOS/test/controls/SpringLoadedThreePosTumbTest.lua
@@ -0,0 +1,112 @@
+local ControlType = require("ControlType")
+local InputType = require("InputType")
+local MockDevice = require("MockDevice")
+local Module = require("Module")
+local OutputType = require("OutputType")
+local PhysicalVariant = require("PhysicalVariant")
+local Suffix = require("Suffix")
+
+local lu = require("luaunit")
+
+--- @class TestSpringLoadedThreePosTumb
+--- @field module Module
+TestSpringLoadedThreePosTumb = {}
+local moduleName = "MyModule"
+local moduleAddress = 0x4200
+
+function TestSpringLoadedThreePosTumb:setUp()
+	self.module = Module:new(moduleName, moduleAddress, {})
+	Input_Processor_Device = MockDevice:new(0)
+end
+
+local id = "MY_SPRING_LOADED3_POS_TUMB"
+local device_id = 1
+local down_switch = 2
+local up_switch = 3
+local arg_number = 4
+local category = "Spring-loaded 3 Position Tumbs"
+local description = "This is a spring-loaded 3-position tumb"
+
+function TestSpringLoadedThreePosTumb:testAdd3PosTumb()
+	local control = self.module:defineSpringloaded_3PosTumb(id, device_id, down_switch, up_switch, arg_number, category, description)
+
+	lu.assertEquals(control, self.module.documentation[category][id])
+	lu.assertEquals(control.control_type, ControlType.three_pos_two_command_switch_open_close)
+	lu.assertEquals(control.category, category)
+	lu.assertEquals(control.description, description)
+	lu.assertEquals(control.identifier, id)
+	lu.assertIsNil(control.physical_variant)
+	lu.assertIsNil(control.api_variant)
+
+	lu.assertEquals(#control.inputs, 1)
+	local set_state_input = control.inputs[1] --[[@as SetStateInput]]
+	lu.assertEquals(set_state_input.interface, InputType.set_state)
+	lu.assertEquals(set_state_input.max_value, 2)
+
+	lu.assertEquals(#control.outputs, 1)
+	local output = control.outputs[1] --[[@as IntegerOutput]]
+	lu.assertEquals(output.type, OutputType.integer)
+	lu.assertEquals(output.max_value, 2)
+	lu.assertEquals(output.suffix, Suffix.none)
+	lu.assertEquals(output.address, moduleAddress) -- first control, should be plenty of room, no need to move the address
+end
+
+function TestSpringLoadedThreePosTumb:testValue()
+	self.module:defineSpringloaded_3PosTumb(id, device_id, down_switch, up_switch, arg_number, category, description)
+
+	local export_hook = self.module.exportHooks[1]
+
+	local alloc = self.module.memoryMap.entries[moduleAddress].allocations[1]
+
+	export_hook(MockDevice:new(-1))
+	lu.assertEquals(alloc.value, 0)
+
+	export_hook(MockDevice:new(0))
+	lu.assertEquals(alloc.value, 1)
+
+	export_hook(MockDevice:new(1))
+	lu.assertEquals(alloc.value, 2)
+end
+
+function TestSpringLoadedThreePosTumb:testInput0()
+	self.module:defineSpringloaded_3PosTumb(id, device_id, down_switch, up_switch, arg_number, category, description)
+	local input_processor = self.module.inputProcessors[id]
+
+	input_processor("0")
+
+	lu.assertEquals(#Input_Processor_Device.clickable_actions, 3)
+	local action1 = Input_Processor_Device.clickable_actions[1]
+	lu.assertAlmostEquals(action1[down_switch], 0)
+	local action2 = Input_Processor_Device.clickable_actions[2]
+	lu.assertAlmostEquals(action2[up_switch], 0)
+	local action3 = Input_Processor_Device.clickable_actions[3]
+	lu.assertAlmostEquals(action3[down_switch], -1)
+end
+
+function TestSpringLoadedThreePosTumb:testInput1()
+	self.module:defineSpringloaded_3PosTumb(id, device_id, down_switch, up_switch, arg_number, category, description)
+	local input_processor = self.module.inputProcessors[id]
+
+	input_processor("1")
+
+	lu.assertEquals(#Input_Processor_Device.clickable_actions, 2)
+	local action1 = Input_Processor_Device.clickable_actions[1]
+	lu.assertAlmostEquals(action1[down_switch], 0)
+	local action2 = Input_Processor_Device.clickable_actions[2]
+	lu.assertAlmostEquals(action2[up_switch], 0)
+end
+
+function TestSpringLoadedThreePosTumb:testInput2()
+	self.module:defineSpringloaded_3PosTumb(id, device_id, down_switch, up_switch, arg_number, category, description)
+	local input_processor = self.module.inputProcessors[id]
+
+	input_processor("2")
+
+	lu.assertEquals(#Input_Processor_Device.clickable_actions, 3)
+	local action1 = Input_Processor_Device.clickable_actions[1]
+	lu.assertAlmostEquals(action1[down_switch], 0)
+	local action2 = Input_Processor_Device.clickable_actions[2]
+	lu.assertAlmostEquals(action2[up_switch], 0)
+	local action3 = Input_Processor_Device.clickable_actions[3]
+	lu.assertAlmostEquals(action3[up_switch], 1)
+end