Core

Selected operating mode of an automatic direction finder.

Aircraft-wide selectable afterburner power level.

Direction of the aircraft's motion relative to the surrounding air mass.

Display unit selected for a cockpit air-temperature indication.

Immutable simulator-neutral view of the clearances currently granted by the simulator's air-traffic-control service.

Immutable advisory for an upcoming simulator-managed controller handoff.

Direction of a simulator-managed airport traffic pattern.

Immutable simulator-neutral description of the runway currently assigned by simulator-managed air traffic control.

Signed main-gear position in the simulator-managed ATC runway coordinate system. The provider's native X/Y/Z names remain below the SDK.

Immutable next-waypoint assignment from simulator-managed air traffic control.

Stable structural regions of the loaded aircraft.

Published top-level metadata for one airport instrument approach.

The published final approach fix and authored procedure values.

The published navigation type of an instrument approach.

The authored approach-light system installed for a runway end.

Enabled approach and runway-end lighting for one runway end.

A published entry route from an initial fix into an approach.

A published communication frequency for an airport.

The operational service carried by an airport frequency.

Provider-neutral descriptive and topology metadata for an airport.

A provider-neutral airport reference from simulator scenery data.

Published object totals for an airport facility. A null value means the provider does not publish that category; zero means it explicitly publishes that no objects of the category exist.

Provider-neutral geometry and authored areas for one helipad.

A provider-neutral active jetway and optional parking association.

The provider-authored extension size of an active jetway.

The authored visual style of an active jetway.

A provider-neutral aircraft parking position at an airport.

The operational purpose and supported aircraft size of a parking position.

A provider-neutral published departure or arrival procedure.

An enroute-specific path into or out of an airport procedure.

The phase of flight served by a published airport procedure.

A runway-specific path into or out of an airport procedure.

Provider-neutral geometry and identity for one physical runway.

One operational end of a physical runway.

An enabled authored pavement area associated with a runway end.

A provider-neutral position from which an aircraft can start.

The authored operational purpose of an airport start position.

The painted marking authored along one side of a taxiway path.

The direction from which a hold-short marking applies.

A complete airport surface graph with authored taxiway names.

The routing role authored for a taxiway network node.

An edge in an airport's provider-neutral surface-routing graph.

The permitted traversal direction of a taxiway graph edge.

The operational purpose of an airport surface path.

A node in an airport's provider-neutral surface-routing graph.

The operational meaning of an airport taxiway graph point.

An installed visual approach-slope indicator beside a runway end.

The authored visual approach-slope indicator arrangement.

Visual state of the pilot altimeter's altitude-alert indication.

Physical sensor source supplying an attitude indication.

Crew position served by a named aircraft audio panel.

Kind of transmitter selected at a crew audio panel.

Simulator-neutral transmitter selection for one crew audio panel. The communication radio is the same named object found in the avionics graph.

Selected automatic-braking mode.

Reported automatic power-reserve state, not a pilot-selected power setting.

Source that requires the autopilot's upcoming altitude capture.

Source from which altitude-hold acquired its current reference.

Operational state of one autopilot/flight-director channel.

Installed real-world autopilot configuration family.

Configured pitch guidance selected when the autopilot needs a default mode.

Configured roll guidance selected when the autopilot needs a default mode.

Aircraft reference used to establish the autopilot's front course.

Autopilot guidance computer selected to fly the aircraft.

Common flight-guidance state and targets at one observation point. Detailed active-mode identities are null when a provider does not expose an authoritative summary.

Reference that supplies the autopilot's heading-mode target.

Current simulator-neutral lateral flight-guidance behavior.

Navigation receiver currently feeding the pilot-side autopilot guidance.

Direction of a manual pitch-trim correction requested by the autopilot.

Aircraft sensor source feeding an autopilot reference axis.

Reference slot selected by a multi-slot autopilot target.

Common targets shown in the aircraft's primary autopilot selector windows. Both speed representations are retained because aircraft may expose and transition between indicated-airspeed and Mach targets independently. Mach is null when the active provider/selector has no separate Mach target.

Observable outputs produced by the autopilot's internal self-test. These outputs remain distinct from the selected test state.

Unit selected for the autopilot's speed-reference control.

Target pair presented by the autopilot's lateral and vertical selectors.

Current simulator-neutral vertical flight-guidance behavior.

Normalized active autothrottle guidance behavior.

Selected operating mode of an auxiliary fuel-transfer pump.

Stable aircraft location of a bleed-air distribution duct.

Stable aircraft location of a pneumatic isolation valve.

Angular motion around the aircraft roll, pitch, and yaw axes.

Force in the aircraft-relative right/up/forward frame.

Moment around the aircraft roll, pitch, and yaw axes.

Velocity of the surrounding air relative to the aircraft, expressed in the aircraft-relative right/up/forward frame.

Three-axis motion in the aircraft-relative right/up/forward frame.

Physical role of a named aircraft cabin entry.

Selected operating mode of an electric cabin heater.

Stable aircraft location of a cabin-pressure pack.

Selected operating mode of the cabin ventilation fan.

Actual operating level of the cabin ventilation fan.

Atmospheric and surface context at the simulation camera. Camera-relative wind angles preserve the provider's signed relative-angle convention and are intentionally distinct from true meteorological wind direction.

Describes a simulator-neutral capability and the operations declared by the selected provider adapter. Supported mappings do not guarantee that the currently loaded aircraft supplies a usable value; the operation result remains authoritative at runtime.

Identifies a stable, simulator-neutral USI capability.

Provider-reported state of an aircraft-carrier catapult launch.

Simulator-rendered sun and moon orientation plus normalized lunar state. Elevation is positive above the horizon and azimuth is clockwise from true north.

The flight-deck position served by an instrument-light rheostat.

The fixed cockpit-panel lighting role controlled by a rheostat.

Semantic kind of cockpit timing instrument.

Channel spacing supported by a communication radio.

Air-traffic service associated with a tuned COM station.

A signed minimum and maximum control authority in stable units.

An owned provider-neutral lease over the simulator camera.

A geographic camera pose in simulator-neutral conventions.

A provider-neutral handle for one traffic aircraft created and owned by this USI connection.

Geographic position and orientation commanded for a client-created traffic aircraft.

Normalized visual configuration and pilot-control presentation for a client-created traffic aircraft.

Why a client-created traffic-aircraft handle stopped being usable.

Reports that a controlled traffic aircraft is no longer active.

Describes a registered simulator provider whose simulator process is currently running. Process names and operating-system details remain private to the provider.

Selected magnetic coupling of an electric directional gyro.

Information presented by a dedicated DME receiver.

NAV receiver supplying remote tuning to a dedicated DME.

WGS-84 Earth-centered, Earth-fixed position in selected length units.

WGS-84 Earth-centered, Earth-fixed aircraft coordinates in meters.

Three-axis motion in the earth-relative east/up/north frame.

Selected operating mode of an engine electric fuel pump.

Stable semantic role of an aircraft electrical load circuit.

A cockpit voltmeter source selected by aircraft-authored electrical-panel semantics.

Stable role of an electronic flight-instrument system.

One coherent navigation solution presented by an electronic flight display.

Aircraft engines currently targeted by shared flight-deck controls.

Preference-aware physical quantities for a named propulsion unit.

Broad simulator-neutral classification of a named engine's propulsion technology. Provider-specific engine subtypes are intentionally normalized into stable categories.

Aircraft-wide engine starting mode.

Aircraft-authored engine thermal references in selected temperature units.

Aircraft-authored engine thermal-model reference temperatures, all in Celsius. These are model configuration, not measured temperatures or failure limits. References for a propulsion technology need not apply to every installed engine.

A provider-neutral geographic point from facility data.

A navigation facility referenced by simulator scenery.

The kind of navigation facility referenced by procedure data.

The material modeled for a runway surface.

Power-lever gate currently requested from a full-authority digital engine controller. Gate labels are intentionally independent of aircraft-specific names such as CRZ, CLB, MCT, FLEX, and TOGA.

Primary quantity regulated by the aircraft's FADEC system.

Common flap deployment plus exact provider-authoritative topology.

Reason actual flap position does not match the selected position.

Describes a transition between running and stopped flight activity.

Current operating state of automated stall protection.

Category of nearby destination offered by the simulator flight assistant.

One readable nearby destination offered by the simulator flight assistant.

Flight-deck station whose primary-control inputs have priority.

Pilot input plus exact optional station and effective demand.

Signed roll, pitch, and yaw demand in normalized control ratios.

Exact mechanical failure modes reported for one control-surface section. Multiple flags may be present when the simulator reports concurrent damage.

Failure state for one numbered, aircraft-relative control-surface section. Section numbers are one-based and stable within the loaded aircraft.

Aircraft-relative lateral location of a control-surface section.

Flight-director channel selected as the guidance master.

Normalized annunciation state for an armable flight-guidance mode.

Selected operating mode of the aircraft load-factor limiter.

Raised after a loaded flight has produced a ready replacement aircraft graph.

Immutable, simulator-neutral snapshot of the leg currently being flown.

Navigation reference supplying the active final-approach solution.

Provider-neutral reason that the active flight plan changed.

A normalized notification raised after USI has observed a flight-plan change and refreshed its common plan metadata.

Provider-neutral coordinates for a user-defined flight-plan waypoint.

Immutable, simulator-neutral location of the calculated top of descent.

Operational vertical-planning advisory from the active flight-management solution.

Provider-neutral identity and location of a flight-plan waypoint. Additional provider data remains an implementation detail of USI.

Provider-neutral kind of an entry in a flight plan.

Active flight-control law reported by an equipped fly-by-wire aircraft.

Flight-control computer selection, health, and protection state.

Forces currently authored for the primary yoke and pedal controls. Signed values preserve the modeled control direction.

Automatic crossfeed controller selection.

Direction and availability of aircraft fuel crossfeed.

Portable selected mode of a fuel pump.

Normalized role of a named fuel pump.

Tank or tank group selected to supply fuel.

Known target of a selector; Unspecified does not imply any engine association.

A normalized location used by an aircraft fuel-transfer route.

Aircraft-wide fuel-transfer operating mode.

Selected auxiliary fuel-transfer system test.

Normalized role of a named fuel valve; identity does not imply achieved flow.

Reason reported by the aircraft's landing-gear warning system.

Preference-aware physical quantities generated from canonical explicit-unit operations.

Provider-neutral formatting for geographic coordinates.

Provider-neutral geodetic position with mean-sea-level altitude.

Normalized phase of an instrument approach in the primary navigator.

Geometry used by the active instrument-approach segment.

Normalized navigation-aid type of a loaded instrument approach.

Operational role of the current instrument-approach waypoint.

Current lateral/vertical service level of satellite navigation guidance.

Radio-frequency field selected for entry on an integrated navigator.

Geodetic position calculated by a satellite-navigation receiver.

Source driving a navigator's vertical-guidance indication.

Provider-neutral automatic sequencing state of the primary navigator.

Reason reported by the ground-proximity warning system.

The published marking or operational purpose of a helipad.

Horizontal earth-relative motion in feet per second. Positive values point east and north respectively, independent of the simulator's native axes.

Flow direction through a reversible hydraulic power-transfer unit.

Operating state of a hydraulic power-transfer unit.

Installed hydraulic power-transfer-unit flow arrangement.

Simulator-neutral access to primary airframe structural health. Provider-native structural slots remain below this surface.

Simulator-neutral access to aircraft autopilot and flight-guidance state.

Simulator-neutral access to auxiliary-power-unit selections.

Simulator-neutral access to occupant-facing cabin state.

Simulator-neutral pilot flight-control inputs for the user aircraft.

Provides simulator-neutral aerodynamic and motion values for the user aircraft.

Simulator-neutral access to aircraft-generated visual effects and their installed equipment.

Developer-facing electrical system and named component collection.

Simulator-neutral indexed engine controls and state for the user aircraft. Engine indexes are zero-based.

Simulator-neutral access to aircraft fuel state.

Simulator-neutral access to aircraft hydraulic state.

Simulator-neutral, zero-based indexed access to aircraft ice-protection state.

Simulator-neutral identity and configuration of the currently loaded user aircraft.

Simulator-neutral access to aircraft lighting state and health.

Simulator-neutral access to aircraft oxygen-system state.

Simulator-neutral access to the loaded aircraft's configured performance limits.

Simulator-neutral access to aircraft pneumatic-source selections.

Simulator-neutral access to actual cabin pressurization state.

Simulator-neutral state of the currently loaded user aircraft.

Simulator-neutral access to aircraft vacuum-system state.

Simulator-neutral access to active aircraft warning state.

Simulator-neutral access to aircraft weight and balance state.

Provides simulator-neutral capability discovery without exposing native SimVar, DataRef, command, or event identifiers.

A typed named channel shared through the selected simulator.

Stable aircraft location of an instrument-air source.

Aircraft-authored warning, caution, and normal operating bands for one instrument. The owning API method defines the engineering unit.

Guidance signals supplied by integrated approach navigation.

Passenger/crew isolation selected on an aircraft intercom.

Selects which jet-engine spool, if any, the aircraft-wide synchronization system attempts to match across engines.

Authored construction of one landing-gear assembly.

Pilot-selected landing-gear handle detent. The neutral/off detent is optional; unsupported providers still expose the common up/down states.

An ILS or localizer facility from simulator navigation data.

Describes whether a usable loaded-aircraft graph is available.

Identifies why USI replaced the currently loaded aircraft component graph.

Raised only after the replacement component graph is ready to resolve.

Precipitation currently affecting the user aircraft.

Wind currently affecting the user aircraft, expressed both as the familiar meteorological direction/speed and signed earth-axis components.

A provider-neutral vector in local east, up, and north axes.

A velocity in local east, up, and north axes.

Airport and runway served by a received localizer.

Current simulator-managed marine traffic. The total can exceed the individually described contacts when the provider exposes only aggregate information for some vessels.

Geographic position and motion for one simulator-managed marine vessel.

Known simulator-managed marine-vessel classifications.

Behavior requested when muting marker-beacon audio.

A marker beacon from simulator navigation data.

Marker-beacon lights currently indicated by the simulator. Multiple flags may be present because some simulators expose the lights independently.

The operational position of a marker beacon on an approach.

Selected reception sensitivity of a marker-beacon receiver.

Warning, caution, and normal bands expressed as typed quantities.

A minimum and maximum expressed as typed physical quantities.

A radio navigation aid from simulator scenery data.

The provider-neutral kind of a radio navigation aid.

Receiver-side state reported for backcourse navigation guidance. This is distinct from the autopilot's backcourse mode.

Navigation source shown by one electronic-flight-display bearing pointer.

Navigation presentation selected on an electronic flight display.

Primary navigation receiver displayed by an electronic flight display.

A named navigation fix from simulator navigation data.

One currently audible element of a navigation-station identifier.

Map presentation selected on an electronic flight display.

Optional information layer presented on an electronic flight display's navigation map.

One coherent set of navigation-map overlay selections.

Lowest and highest terrain elevations currently represented by one navigation display.

North reference used by an electronic flight display's navigation map.

Navigation receiver previewed on an electronic flight display.

Selected electrical and interrogation mode of a navigation receiver.

Provider-neutral kind of navigation signal currently received by a navigation radio.

How a navigation receiver's frequency is being controlled.

Normalized TO/FROM indication reported by a navigation receiver.

The kind of nearby-aircraft change notification.

Describes a nearby-aircraft change or a provider request to refresh the complete snapshot.

A simulator-neutral snapshot of another aircraft reported near the user aircraft.

Provider-neutral exterior-light state for a nearby aircraft.

Selected delivery mode for the crew oxygen regulator.

Hydraulic valve arrangement used to hold parking-brake pressure.

Provides the normalized pause state after a simulator state change.

Selected piston-engine magneto combination.

Selected operating mode for a pitot-probe heater.

Selected operating mode of pneumatic deicing boots.

Selected airflow schedule of a cabin-pressure pack.

Operating mode selected for a pneumatic valve.

Power-lever travel within a selected range, from zero at the range entrance to one at its far end. The reading method identifies whether this is hardware input or aircraft lever intent; neither represents measured thrust. Beta's far end and reverse's entrance share a detent; reads report that shared detent as Reverse with zero travel.

The operating interval selected by an engine power lever.

Active predictive-windshear phase reported by onboard weather radar.

Selected source supplying air to the pressurization system.

A normalized altitude constraint for a procedure leg.

The semantic form of a published altitude constraint.

The north reference used by a procedure leg's bearing and course.

A referenced procedure facility with its authored location.

One normalized path-termination leg in a published procedure.

The path-termination rule used by a published procedure leg.

A normalized indicated-airspeed constraint for a procedure leg.

The semantic form of a published indicated-airspeed constraint.

The permitted turn direction for a procedure leg.

Configured propeller response when governor oil pressure is lost.

Aircraft-authored propeller pitch limits as typed angles.

Aircraft-authored propeller pitch limits in degrees.

Direction a propeller rotates when viewed from behind the aircraft.

Selected operating mode for an engine's propulsive device.

Aircraft-wide throttle-control failures that may be reported together.

Direction requested from simulator-managed pushback service.

Navigation source shown by a radio-magnetic indicator or pointer.

Named maneuvering-rocket control direction, not measured acceleration.

Editable base conditions for the simulator's regional weather model. These values describe the regional model, not necessarily the conditions currently affecting the user aircraft or simulation camera.

Selected position of a retractable-float control.

Direction currently requesting roll-spoiler assistance.

Reason actual slat position does not match the selected position.

Combined slat/flap configuration shown by equipped aircraft.

Slung-load dimensions using the developer's selected length unit.

Axis-aligned dimensions of a slung load in feet.

Slung-load orientation using the developer's selected angle unit.

Current orientation of a slung load in degrees.

Electrical configuration used to power the engine starters.

Preference-aware projections for structured physical values.

A provider-neutral TACAN channel selection.

Band suffix of a TACAN channel.

Determines whether tailplane protection follows the wing system or is selected independently.

Physical terrain or moving surface resolved at a geographic location.

Current operational availability of an engine thrust reverser.

Selected delivery rate of a TKS fluid ice-protection system.

Reason the simulator reports for the most recent tow-cable release.

Altitude range shown by traffic-advisory equipment.

Current voice/display message from collision-avoidance equipment.

Normalized operating mode of traffic-advisory equipment.

Flight-deck pressure source used by traffic-advisory equipment.

Sensitivity level currently used by collision-avoidance threat logic.

A vertical-speed interval displayed by collision-avoidance equipment.

Current collision-avoidance vertical-speed guidance. A null band means the equipment is not displaying that interval.

A simulator-neutral aircraft model and livery that the provider can create as controlled traffic.

Collision-avoidance classification assigned to a nearby aircraft contact.

Discrete operating detent of a turbine-engine condition lever.

Selected operating mode of a turbine-engine ignition system.

Identifies a normalized SDK diagnostic without exposing provider-native error codes or callback details.

Describes the provider-neutral outcome of an SDK operation.

Construction-time options for a USI session.

Per-USI-instance measurement preferences. Replacing is atomic, so an operation observes either the old or new complete profile.

The non-value result returned by USI writes, actions, and service requests. Expected simulator and aircraft limitations are represented by rather than provider-native exceptions.

The value-bearing result returned by USI reads and queries.

Built-in developer-facing unit profiles.

Immutable unit choices used to project USI's canonical physical values at the developer boundary. Simulator adapters never observe these choices.

Observed presentation state of vacuum-driven instruments.

Configured vacuum-instrument pressure bands.

Selected combined nose-and-visor configuration.

Mixed-reality passthrough presentation selected by the simulator.

Allowed speed band around the VNAV economy descent target.

ICAO wake-turbulence category of an aircraft.

Weapon firing sequence selected by the flight crew.

Current computed gun-sight aim and target range.

Atmospheric conditions sampled by the simulator at one location.

A modeled cloud layer. Providers that blend cloud forms expose the adjacent classifications and a zero-through-one blend ratio.

A provider-neutral cloud classification.

Structured regional atmospheric layers.

Multi-elevation scan strategy selected for weather radar on one display.

Operating presentation selected for weather radar on one flight display.

Coherent role-aware weather-radar presentation state.

Shared weather-radar antenna scan geometry and rate.

Typed angular-tilt or selected-altitude vertical targeting.

How a weather-radar presentation selects its vertical scan target.

A geodetic point at which simulator weather is sampled.

A modeled regional temperature and dew-point level.

A modeled regional wind layer.

Windshear warning reported by the aircraft warning system.

Selected speed of a flight-deck windshield wiper.

Fixed total wing area and span in the selected working units.

Physical constants and average sea-level reference conditions used by the simulator's world model. These are model inputs, not local weather.