Aircraft Flight Model Variables
The tables below indicate the properties for the Simulation Variables that can be used to get and set properties related to the physical properties and flight model of an aircraft. For information on the units listed for each variable, please see here: Simulation Variable Units
You can find a complete index of all available SimVars here: SimVar Index
General
| Simulation Variable | Index | Description | Units | Settable |
|---|---|---|---|---|
BETA DOT | N/A | Beta dot | Radians per second | |
DECISION ALTITUDE MSL | N/A | Design decision altitude above mean sea level | Feet (ft) | |
DECISION HEIGHT | N/A | Design decision height. This can be set for the aircraft in the FLT file using the DecisionHeight parameter. If not set it will default to 200. | Feet (ft) | |
DESIGN CRUISE ALT | N/A | This design constant represents the optimal altitude the aircraft should maintain when in cruise. It is derived from the cruise_alt setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default is 1500ft. | Feet (ft) | |
DESIGN SPAWN ALTITUDE CRUISE | N/A | This design constant represents the spawn altitude for the aircraft when spawning in cruise. It is derived from the spawn_cruise_altitude setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default is 1500ft. | Feet (ft) | |
DESIGN SPAWN ALTITUDE DESCENT | N/A | This design constant represents the spawn altitude for the aircraft when spawning in descent. It is derived from the spawn_descent_altitude setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default is 500ft. | Feet (ft) | |
DESIGN SPEED CLIMB | N/A | This design constant represents the optimal climb speed for the aircraft. It is derived from the climb_speed setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default value is -1. | Feet (ft) per second | |
DESIGN SPEED MIN ROTATION | N/A | This design constant represents the minimum speed required for aircraft rotation. It is derived from the rotation_speed_min setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default value is -1. | Feet (ft) per second | |
DESIGN SPEED VC | N/A | This design constant represents the aircraft ideal cruising speed. It is derived from the cruise_speed setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. The default value is computed an internal function that uses the estimated cruise altitude and estimated cruise percent power, according of the engine type, the number of engines, the density, the wing area and some drag parameters. Normally this value is set in the CFG file and the default value is never used. | Feet (ft) per second | |
DESIGN SPEED VS0 | N/A | This design constant represents the the stall speed when flaps are fully extended. It is derived from the full_flaps_stall_speed setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default value is 0.8 x VS. | kias | |
DESIGN SPEED VS1 | N/A | This design constant represents the stall speed when flaps are fully retracted. It is derived from the flaps_up_stall_speed setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. Default value is 0. | kias | |
DESIGN TAKEOFF SPEED | N/A | This design constant represents the aircraft ideal takoff speed. It is derived from the takeoff_speed setting in the [REFERENCE SPEEDS] section of the flight_model.cfg. | Knots | |
DYNAMIC PRESSURE | N/A | Dynamic pressure | Pounds per square foot (psf) | |
ESTIMATED CRUISE SPEED | N/A | Estimated cruise speed | Feet (ft) per second | |
G FORCE | N/A | Current G force | GForce | |
G LIMITER SETTING | N/A | This returns the setting of the G-limiter, as set using the GLimiterSetting parameter. | Enum:0 = Off1 = On2 = Override | |
INCIDENCE ALPHA | Group ID(0, 1 or 2) | The angle of attack based on the polling point selected using the group ID. For more information please see here: Note On Physics Groups | Radians | |
INCIDENCE BETA | N/A | Sideslip angle | Radians | |
IS TAIL DRAGGER | N/A | True if the aircraft is a taildragger | Bool | |
LINEAR CL ALPHA | N/A | Linear CL alpha | Per radian | |
MACH MAX OPERATE | N/A | Maximum design mach | Mach | |
MAX G FORCE | N/A | Maximum G force attained | Gforce | |
MIN DRAG VELOCITY | N/A | Minimum drag velocity, in clean, with no input and no gears, when at 10000ft. | Feet (ft) per second | |
MIN G FORCE | N/A | Minimum G force attained | Gforce | |
REFERENCE SPEED MAX IAS | N/A | The maximum IAS that the aircraft can fly at. | Knots | |
REFERENCE SPEED MAX IAS GEAR DOWN | N/A | The maximum IAS that the aircraft can fly at with the landing gear extended. | Knots | |
SEMIBODY LOADFACTOR X | N/A | Deprecated, do not use! | Number | |
SEMIBODY LOADFACTOR Y | N/A | Acceleration along the axis Y divided by the gravity constant G (usually around 9.81m.s²) | Number | |
SEMIBODY LOADFACTOR YDOT | N/A | Derivative of SEMIBODY LOADFACTOR Y in relation to time. | Per second | |
SEMIBODY LOADFACTOR Z | N/A | Deprecated, do not use! | Number | |
SIGMA SQRT | N/A | Sigma sqrt | Number | |
SIMULATED RADIUS | N/A | Simulated radius | Feet (ft) | |
STALL ALPHA | N/A | The angle of attack which produces the maximum lift coefficient before entering into stall conditions. | Radians | |
STATIC PITCH | N/A | The angle at which static pitch stability is achieved. | Radians | |
TYPICAL DESCENT RATE | N/A | the typical (normal) descent rate for the aircraft. | Feet (ft) per minute | |
WING AREA | N/A | Total wing area | Square feet (ft) | |
WING FLEX PCT | N/A | The current wing flex. Different values can be set for each wing (for example, during banking). Set an index of 1 for the left wing, and 2 for the right wing. | Percent Over 100 | |
WING SPAN | N/A | Total wing span | Feet (ft) | |
YAW STRING ANGLE | N/A | The yaw string angle. Yaw strings are attached to gliders as visible indicators of the yaw angle. Will only work when the yaw_string_available parameter is set to 1 (True). | Radians | |
YAW STRING PCT EXTENDED | N/A | Yaw string angle as a percentage. Will only work when the yaw_string_available parameter is set to 1 (True). | Percent Over 100 | |
ZERO LIFT ALPHA | N/A | The angle of attack at which the wing has zero lift. | Radians |
Center Of Gravity
| Simulation Variable | Index | Description | Units | Settable |
|---|---|---|---|---|
CG AFT LIMIT | N/A | Most backward authorized position of the CG according to the POH.NOTE: This is only valid for airplanes. | Percent Over 100 | |
CG FEET | N/A | The longitudinal CG position relative to the Datum Reference Point.NOTE: This is only valid for helicopters. | Feet (ft) | |
CG FEET AFT LIMIT | N/A | The aft CG limit position relative to the Datum Reference Point.NOTE: This is only valid for helicopters. | Feet (ft) | |
CG FEET LATERAL | N/A | The lateral CG position relative to the Datum Reference Point.NOTE: This is only valid for helicopters. | Feet (ft) | |
CG FEET LATERAL LEFT LIMIT | N/A | The left hand lateral CG position relative to the Datum Reference Point.NOTE: This is only valid for helicopters. | Feet (ft) | |
CG FEET LATERAL RIGHT LIMIT | N/A | The right hand lateral CG position relative to the Datum Reference Point.NOTE: This is only valid for helicopters. | Feet (ft) | |
CG FEET FWD LIMIT | N/A | The forward CG limit position relative to the Datum Reference Point.NOTE: This is only valid for helicopters. | Feet (ft) | |
CG FWD LIMIT | N/A | Most forward authorized position of the CG according to the POH.NOTE: This is only valid for airplanes. | Percent Over 100 | |
CG MAX MACH | N/A | Deprecated, do not use! | Mach | |
CG MIN MACH | N/A | Deprecated, do not use! | Mach | |
CG PERCENT | N/A | Longitudinal CG position as a percent of reference Chord.NOTE: This is only valid for airplanes. | Percent Over 100 | |
CG PERCENT LATERAL | N/A | Lateral CG position as a percent of reference Chord.NOTE: This is only valid for airplanes. | Percent Over 100 | |
STATIC CG TO GROUND | N/A | Static CG position with reference to the ground.NOTE: This is only valid for airplanes. | Feet (ft) |
Interactive Points
These SimVars are used in relation to the values of the Interactive Points that have been defined for the aircraft. Each of these SimVars requires a name (or an index value) to be supplied, and this is the name (or index) of the corresponding interactive_point.N defined in the appropriate CFG file. This name can be given using the following format:
[SimVar]:'[COMPONENT_NAME]'_nFor example:
(A:INTERACTIVE POINT BANK:'Door_1'_n, Volts)It should be noted that there are two versions of these SimVars, and for all aircraft developed specifically for MSFS 2024 you should be using the EX1 versions. The legacy versions do not work well with the '[COMPONENT_NAME]'_n format, and will fall back to index 0 when given an invalid index/name parameter. The EX1 versions will instead either return default values or simply do nothing.
| Simulation Variable | Index | Description | Units | Settable |
|---|---|---|---|---|
INTERACTIVE POINT BANK | Point Name (or index) | Interactive Point orientation: Bank. | Degrees | |
INTERACTIVE POINT BANK EX1 | Point Name (or index) | Interactive Point orientation: Bank. | Degrees | |
INTERACTIVE POINT HEADING | Point Name (or index) | Interactive Point orientation: Heading. | Degrees | |
INTERACTIVE POINT HEADING EX1 | Point Name (or index) | Interactive Point orientation: Heading. | Degrees | |
INTERACTIVE POINT JETWAY LEFT BEND | Point Name (or index) | Interactive Point Jetway constant, determining the desired left bend ratio of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY LEFT BEND EX1 | Point Name (or index) | Interactive Point Jetway constant, determining the desired left bend ratio of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY LEFT DEPLOYMENT | Point Name (or index) | Interactive Point Jetway constant, determining the desired left deployment angle of jetway hood. | Degrees | |
INTERACTIVE POINT JETWAY LEFT DEPLOYMENT EX1 | Point Name (or index) | Interactive Point Jetway constant, determining the desired left deployment angle of jetway hood. | Degrees | |
INTERACTIVE POINT JETWAY RIGHT BEND | Point Name (or index) | Interactive Point Jetway constant, determining the desired right bend ratio of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY RIGHT BEND EX1 | Point Name (or index) | Interactive Point Jetway constant, determining the desired right bend ratio of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY RIGHT DEPLOYMENT | Point Name (or index) | Interactive Point Jetway constant, determining the desired right deployment angle of jetway hood. | Degrees | |
INTERACTIVE POINT JETWAY RIGHT DEPLOYMENT EX1 | Point Name (or index) | Interactive Point Jetway constant, determining the desired right deployment angle of jetway hood. | Degrees | |
INTERACTIVE POINT JETWAY TOP HORIZONTAL | Point Name (or index) | Interactive Point Jetway constant, determining the desired top horizontal ratio of displacement of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY TOP HORIZONTAL EX1 | Point Name (or index) | Interactive Point Jetway constant, determining the desired top horizontal ratio of displacement of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY TOP VERTICAL | Point Name (or index) | Interactive Point Jetway constant, determining the desired top vertical ratio of displacement of jetway hood. | Percent | |
INTERACTIVE POINT JETWAY TOP VERTICAL EX1 | Point Name (or index) | Interactive Point Jetway constant, determining the desired top vertical ratio of displacement of jetway hood. | Percent | |
INTERACTIVE POINT GOAL | Point Name (or index) | The Interactive Point goal percentage of opening (if it’s for a door) or percentage of deployment (if it’s for a hose or cable). | Percent Over 100 | |
INTERACTIVE POINT GOAL EX1 | Point Name (or index) | The Interactive Point goal percentage of opening (if it’s for a door) or percentage of deployment (if it’s for a hose or cable). | Percent Over 100 | |
INTERACTIVE POINT OPEN | Point Name (or index) | Interactive Point current percentage of opening (if door) or deployment (if hose/cable). | Percent Over 100 | |
INTERACTIVE POINT OPEN EX1 | Point Name (or index) | Interactive Point current percentage of opening (if door) or deployment (if hose/cable). | Percent Over 100 | |
INTERACTIVE POINT PITCH | Point Name (or index) | Interactive Point orientation: Pitch. | Degrees | |
INTERACTIVE POINT PITCH EX1 | Point Name (or index) | Interactive Point orientation: Pitch. | Degrees | |
INTERACTIVE POINT POSX | Point Name (or index) | Interactive Point X position relative to the Datum Reference Point. | Feet (ft) | |
INTERACTIVE POINT POSX EX1 | Point Name (or index) | Interactive Point X position relative to the Datum Reference Point. | Feet (ft) | |
INTERACTIVE POINT POSY | Point Name (or index) | Interactive Point Y position relative to the Datum Reference Point. | Feet (ft) | |
INTERACTIVE POINT POSY EX1 | Point Name (or index) | Interactive Point Y position relative to the Datum Reference Point. | Feet (ft) | |
INTERACTIVE POINT POSZ | Point Name (or index) | Interactive Point Z position relative to the Datum Reference Point. | Feet (ft) | |
INTERACTIVE POINT POSZ EX1 | Point Name (or index) | Interactive Point Z position relative to the Datum Reference Point. | Feet (ft) | |
INTERACTIVE POINT TYPE | Point Name (or index) | The type of interactive point. | Enum:0: Main exit1: Cargo exit/door2: Emergency exit3: Fuel hose4: Ground Power cable5: Air Start Unit6: Tailhook7 Drop Exit (for skydiving)8 Window99: Unknown (for error handling) | |
INTERACTIVE POINT TYPE EX1 | Point Name (or index) | The type of interactive point. | Enum:0: Main exit1: Cargo exit/door2: Emergency exit3: Fuel hose4: Ground Power cable5: Air Start Unit6: Tailhook7 Drop Exit (for skydiving)8 Window99: Unknown (for error handling) |
Weight
| Simulation Variable | Index | Description | Units | Settable |
|---|---|---|---|---|
EMPTY WEIGHT | N/A | Empty weight of the aircraft | Pounds (lbs) | |
EMPTY WEIGHT CROSS COUPLED MOI | N/A | Empty weight cross coupled moment of inertia | Slugs per feet squared (slug sqft) | |
EMPTY WEIGHT PITCH MOI | N/A | Empty weight pitch moment of inertia | Slugs per feet squared (slug sqft) | |
EMPTY WEIGHT ROLL MOI | N/A | Empty weight roll moment of inertia | Slugs per feet squared (slug sqft) | |
EMPTY WEIGHT YAW MOI | N/A | Empty weight yaw moment of inertia | Slugs per feet squared (slug sqft) | |
MAX GROSS WEIGHT | N/A | Maximum gross weight of the aircraft as defined by the max_gross_weight parameter. | Pounds (lbs) | |
MAX LANDING WEIGHT | N/A | The maximum weight at which the aircraft is certified to land safely.Default value will be equal to the MAX TAKEOFF WEIGHT if available, otherwise it will be the MAX GROSS WEIGHT. | Pounds (lbs) | |
MAX TAKEOFF WEIGHT | N/A | The maximum weight at which the aircraft is certified to comply with all airworthiness requirements.Default value is the MAX GROSS WEIGHT. | Pounds (lbs) | |
MAX ZERO FUEL WEIGHT | N/A | The maximum weight of the aircraft when fully loaded but with empty fuel tanks as defined by the max_zero_fuel_weight parameter. | Pounds (lbs) | |
TOTAL WEIGHT | N/A | Total weight of the aircraft | Pounds (lbs) | |
TOTAL WEIGHT CROSS COUPLED MOI | N/A | Total weight cross coupled moment of inertia | Slugs per feet squared | |
TOTAL WEIGHT PITCH MOI | N/A | Total weight pitch moment of inertia | Slugs per feet squared | |
TOTAL WEIGHT ROLL MOI | N/A | Total weight roll moment of inertia | Slugs per feet squared | |
TOTAL WEIGHT YAW MOI | N/A | Total weight yaw moment of inertia | Slugs per feet squared |