isqx.aerospace

Quantity kinds in aerospace (TAS, CAS, geopotential altitude etc.)

aerospace

Units and quantities common in aerospace engineering.

See: isqx._citations.ICAO

HEADING

HEADING = QtyKind(RAD, ('heading',))

Wikidata: Q4384217

HEADING_TRUE

HEADING_TRUE = HEADING['true']

HEADING_MAG

HEADING_MAG = HEADING['magnetic']

HEADING_TRUE_WIND

HEADING_TRUE_WIND = HEADING_TRUE['wind']

HEADING_MAG_WIND

HEADING_MAG_WIND = HEADING_MAG['wind']

GROUND_TRACK

GROUND_TRACK = HEADING['ground_track']

Direction of the aircraft's velocity vector relative to the ground.

PRESSURE_ALTITUDE

PRESSURE_ALTITUDE = ALTITUDE['pressure']

Pressure altitude, as measured by the altimeter (standard pressure setting 1013.25 hPa).

Wikidata: Q3233965

DENSITY_ALTITUDE

DENSITY_ALTITUDE = ALTITUDE['density']

Density altitude, as measured by the altimeter.

Wikidata: Q1209487

GEOPOTENTIAL_ALTITUDE

GEOPOTENTIAL_ALTITUDE = ALTITUDE['geopotential']

Geopotential altitude, as measured from mean sea level.

Wikidata: Q12432978

GEOMETRIC_ALTITUDE

GEOMETRIC_ALTITUDE = ALTITUDE['geometric']

Altitude measured from mean sea level (e.g. via GNSS).

GEODETIC_HEIGHT

GEODETIC_HEIGHT = QtyKind(M, ('height', 'geodetic'))

Height above the reference ellipsoid.

HEIGHT_ABOVE_GROUND_LEVEL

HEIGHT_ABOVE_GROUND_LEVEL = QtyKind(
    M, ("height", "above_ground_level")
)

Height above ground level (radio altimeter).

L_OVER_D

L_OVER_D = ratio(LIFT(N), DRAG(N))

K_PERM

K_PERM = K * M ** -1

Kelvin per meter, a unit of temperature gradient. For use in ISA.

ENERGY_HEIGHT

ENERGY_HEIGHT = LENGTH['energy_height']

Specific energy expressed as a height.

Symbol: $H_e$

$$H_e = h + \frac{V^2}{2g}$$

$ H_e $

=

Energy height (meter)

$ h $

=

Geometric altitude (meter)

$ V $

=

True airspeed (meter · second⁻¹)

$ g $

=

Acceleration of free fall (meter · second⁻²)

SPECIFIC_EXCESS_POWER

SPECIFIC_EXCESS_POWER = QtyKind(
    M_PERS, ("specific_excess_power",)
)

Symbol: $P_s$

$$P_s = \frac{dH_e}{dt} = V \left(\frac{T-D}{W}\right)$$

$ P_s $

=

Specific excess power (meter · second⁻¹)

$ H_e $

=

Energy height (meter)

$ t $

=

Time (second)

$ V $

=

True airspeed (meter · second⁻¹)

$ T $

=

Thrust (newton)

$ D $

=

Drag (newton)

$ W $

=

Weight (newton)

WINGSPAN

WINGSPAN = LENGTH['wingspan']

Wikidata: Q245097

Symbol: $b$

CHORD

CHORD = LENGTH['chord']

Wikidata: Q1384332

Symbol: $c$

MEAN_AERODYNAMIC_CHORD

MEAN_AERODYNAMIC_CHORD = CHORD['mean_aerodynamic']

Mean aerodynamic chord (MAC).

Symbols: $\bar{c}$, $MAC$

$$\bar{c} = \frac{2}{S} \int_0^{b/2} c(y)^2 dy$$

$ \bar{c} $

=

Mean aerodynamic chord (meter)

$ S $

=

Wing area (meter²)

$ b $

=

Wingspan (meter)

$ c(y) $

=

Chord at spanwise position y (meter)

MEAN_GEOMETRIC_CHORD

MEAN_GEOMETRIC_CHORD = CHORD['mean_geometric']

Mean geometric chord (Standard Mean Chord).

WING_AREA

WING_AREA = AREA['wing']

Reference wing area.

Symbols: $S$, $S_{ref}$

WETTED_AREA

WETTED_AREA = AREA['wetted']

Wikidata: Q3505294

Symbol: $S_{wet}$

PLANFORM_AREA

PLANFORM_AREA = AREA['planform']

FRONTAL_AREA

FRONTAL_AREA = AREA['frontal']

Cross-sectional area perpendicular to the flow.

DISK_AREA

DISK_AREA = AREA['disk']

Area swept by a propeller or rotor.

TAIL_AREA

TAIL_AREA = AREA['tail']

TAIL_MOMENT_ARM

TAIL_MOMENT_ARM = LENGTH['tail_moment_arm']

ASPECT_RATIO

ASPECT_RATIO = Dimensionless('aspect_ratio')

Wikidata: Q1545619

Symbol: $AR$

$$AR = \frac{b^2}{S}$$

$ AR $

=

Aspect ratio (dimensionless)

$ b $

=

Wingspan (meter)

$ S $

=

Wing area (meter²)

TAPER_RATIO

TAPER_RATIO = Dimensionless('taper_ratio')

Symbol: $\lambda$

$$\lambda = \frac{c_t}{c_r}$$

$ \lambda $

=

Taper ratio (dimensionless)

$ c_t $

=

Chord at tip (meter)

$ c_r $

=

Chord at root (meter)

SWEEP_ANGLE

SWEEP_ANGLE = QtyKind(RAD, ('angle', 'sweep'))

Symbols: $\Lambda$, $\Delta$

DIHEDRAL_ANGLE

DIHEDRAL_ANGLE = QtyKind(RAD, ('angle', 'dihedral'))

Wikidata: Q1972636

Symbol: $\Gamma$

TWIST_ANGLE

TWIST_ANGLE = QtyKind(RAD, ('angle', 'twist'))

Washout or washin angle.

FINENESS_RATIO

FINENESS_RATIO = Dimensionless('fineness_ratio')

Ratio of length to maximum diameter for a fuselage or body.

ANGLE_OF_ATTACK

ANGLE_OF_ATTACK = QtyKind(RAD, ("angle", "angle_of_attack"))

Angle between the chord line and the relative wind vector.

Wikidata: Q370906

Symbol: $\alpha$

SIDESLIP_ANGLE

SIDESLIP_ANGLE = QtyKind(RAD, ('angle', 'sideslip'))

Angle between the relative wind vector and the plane of symmetry.

Symbol: $\beta$

DOWNWASH_ANGLE

DOWNWASH_ANGLE = QtyKind(RAD, ('angle', 'downwash'))

Symbols: $\varepsilon$, $\epsilon$

CRITICAL_MACH_NUMBER

CRITICAL_MACH_NUMBER = MACH_NUMBER['critical']

Wikidata: Q1777346

Symbol: $M_{cr}$

DRAG_DIVERGENCE_MACH_NUMBER

DRAG_DIVERGENCE_MACH_NUMBER = MACH_NUMBER["drag_divergence"]

Wikidata: Q5304818

Symbol: $M_{dd}$

ZERO_LIFT_DRAG_COEFFICIENT

ZERO_LIFT_DRAG_COEFFICIENT = DRAG_COEFFICIENT['zero_lift']

Symbol: $C_{D,0}$

LIFT_INDUCED_DRAG_COEFFICIENT

LIFT_INDUCED_DRAG_COEFFICIENT = DRAG_COEFFICIENT[
    "lift_induced"
]

Wikidata: Q7108183

Symbol: $C_{D,i}$

$$C_{D,i} = \frac{C_L^2}{\pi e AR}$$

$ C_{D,i} $

=

Lift induced drag coefficient (dimensionless)

$ C_L $

=

Lift coefficient (dimensionless)

$ e $

=

Oswald efficiency (dimensionless)

$ AR $

=

Aspect ratio (dimensionless)

INDUCED_DRAG_COEFFICIENT

INDUCED_DRAG_COEFFICIENT = DRAG_COEFFICIENT['induced']

Symbol: $C_{D,i}$

OSWALD_EFFICIENCY

OSWALD_EFFICIENCY = Dimensionless(
    "oswald_efficiency_factor"
)

Span efficiency factor.

Wikidata: Q7108183

Symbol: $e$

PITCHING_MOMENT_COEFFICIENT

PITCHING_MOMENT_COEFFICIENT = Dimensionless(
    "pitching_moment_coefficient"
)

Symbol: $C_m$

$$C_m = \frac{M}{q_\infty S \bar{c}}$$

$ C_m $

=

Pitching moment coefficient (dimensionless)

$ M $

=

Pitching moment (newton · meter)

$ q_\infty $

=

freestream dynamic pressure (pascal)

$ S $

=

Wing area (meter²)

$ \bar{c} $

=

Mean aerodynamic chord (meter)

ROLLING_MOMENT_COEFFICIENT

ROLLING_MOMENT_COEFFICIENT = Dimensionless(
    "rolling_moment_coefficient"
)

Symbol: $C_l$

$$C_l = \frac{L}{q_\infty S b}$$

$ C_l $

=

Rolling moment coefficient (dimensionless)

$ L $

=

Rolling moment (newton · meter)

$ q_\infty $

=

freestream dynamic pressure (pascal)

$ S $

=

Wing area (meter²)

$ b $

=

Wingspan (meter)

YAWING_MOMENT_COEFFICIENT

YAWING_MOMENT_COEFFICIENT = Dimensionless(
    "yawing_moment_coefficient"
)

Symbol: $C_n$

$$C_n = \frac{N}{q_\infty S b}$$

$ C_n $

=

Yawing moment coefficient (dimensionless)

$ N $

=

Yawing moment (newton · meter)

$ q_\infty $

=

freestream dynamic pressure (pascal)

$ S $

=

Wing area (meter²)

$ b $

=

Wingspan (meter)

PRESSURE_COEFFICIENT

PRESSURE_COEFFICIENT = Dimensionless("pressure_coefficient")

Wikidata: Q1260777

Symbol: $C_p$

$$C_p = \frac{p - p_\infty}{q_\infty}$$

$ C_p $

=

Pressure coefficient (dimensionless)

$ p $

=

Static pressure (pascal)

$ p_\infty $

=

freestream static pressure (pascal)

$ q_\infty $

=

freestream dynamic pressure (pascal)

SKIN_FRICTION_COEFFICIENT

SKIN_FRICTION_COEFFICIENT = Dimensionless(
    "skin_friction_coefficient"
)

Symbol: $C_f$

LIFT_SLOPE

LIFT_SLOPE = Dimensionless('lift_slope')

Change in lift coefficient per unit angle of attack (per radian).

Symbols: $C_{L_\alpha}$, $a$

$$C_{L_\alpha} = \frac{dC_L}{d\alpha}$$

$ C_{L_\alpha} $

=

Lift slope (dimensionless)

$ C_L $

=

Lift coefficient (dimensionless)

$ \alpha $

=

Angle of attack (dimensionless)

CIRCULATION

CIRCULATION = QtyKind(M ** 2 * S ** -1, ('circulation',))

Symbol: $\Gamma$

$$\Gamma = \oint_C \boldsymbol{v} \cdot d\boldsymbol{l}$$

$ \Gamma $

=

Circulation (meter² · second⁻¹)

$ \boldsymbol{v} $

=

Velocity (meter · second⁻¹)

$ d\boldsymbol{l} $

=

Line element (meter)

$ C $

=

Closed curve enclosing the body

AIRCRAFT_MASS

AIRCRAFT_MASS = MASS['aircraft']

GROSS

GROSS = AIRCRAFT_MASS['gross']

CARGO_CAPACITY

CARGO_CAPACITY = AIRCRAFT_MASS['cargo_capacity']

FUEL_CAPACITY

FUEL_CAPACITY = AIRCRAFT_MASS['fuel_capacity']

TAKEOFF_MASS

TAKEOFF_MASS = AIRCRAFT_MASS['takeoff']

LANDING_MASS

LANDING_MASS = AIRCRAFT_MASS['landing']

MAXIMUM_TAKEOFF_WEIGHT

MAXIMUM_TAKEOFF_WEIGHT = TAKEOFF_MASS['maximum']

ZERO_FUEL_WEIGHT

ZERO_FUEL_WEIGHT = AIRCRAFT_MASS['zero_fuel_weight']

OPERATING_EMPTY_WEIGHT

OPERATING_EMPTY_WEIGHT = AIRCRAFT_MASS['operating_empty']

PAYLOAD

PAYLOAD = AIRCRAFT_MASS['payload']

EMPTY_WEIGHT

EMPTY_WEIGHT = AIRCRAFT_MASS['empty']

TANK_CAPACITY

TANK_CAPACITY = QtyKind(L, ('aircraft', 'tank_capacity'))

ENDURANCE

ENDURANCE = QtyKind(HOUR, ('aircraft', 'endurance'))

WING_LOADING

WING_LOADING = QtyKind(N * M ** -2, ('wing_loading',))

Weight of the aircraft divided by the wing area.

Wikidata: Q887216

Symbol: $W/S$

$$W/S = \frac{W}{S}$$

$ W/S $

=

Wing loading (newton · meter⁻²)

$ W $

=

Gross (kilogram)

$ S $

=

Wing area (meter²)

POWER_LOADING

POWER_LOADING = QtyKind(N * W ** -1, ('power_loading',))

Weight of the aircraft divided by the engine power.

THRUST_LOADING

THRUST_LOADING = Dimensionless('thrust_loading')

Thrust to weight ratio.

Symbol: $T/W$

$$T/W = \frac{T}{W}$$

$ T/W $

=

Thrust loading (dimensionless)

$ T $

=

Thrust (newton)

$ W $

=

Gross (kilogram)

LOAD_FACTOR

LOAD_FACTOR = Dimensionless('load_factor')

Ratio of lift to weight (n).

Wikidata: Q1340282

Symbol: $n$

$$n = \frac{L}{W}$$

$ n $

=

Load factor (dimensionless)

$ L $

=

Lift (newton)

$ W $

=

Weight (newton)

ANGULAR_VELOCITY

ANGULAR_VELOCITY = QtyKind(RAD_PERS, ('angular_velocity',))

ROLL_RATE

ROLL_RATE = ANGULAR_VELOCITY['roll']

Angular velocity about the body X axis.

Symbol: $p$

PITCH_RATE

PITCH_RATE = ANGULAR_VELOCITY['pitch']

Angular velocity about the body Y axis.

Symbol: $q$

YAW_RATE

YAW_RATE = ANGULAR_VELOCITY['yaw']

Angular velocity about the body Z axis.

Symbol: $r$

TURN_RATE

TURN_RATE = ANGULAR_VELOCITY['turn']

Rate of change of heading.

ATTITUDE

ATTITUDE = QtyKind(RAD, ('attitude',))

BANK_ANGLE

BANK_ANGLE = ATTITUDE['bank']

Symbol: $\phi$

PITCH_ANGLE

PITCH_ANGLE = ATTITUDE['pitch']

Symbol: $\theta$

FLIGHT_PATH_ANGLE

FLIGHT_PATH_ANGLE = ATTITUDE['flight_path']

Angle between the velocity vector and the horizon.

Symbol: $\gamma$

AIRCRAFT_MOMENT

AIRCRAFT_MOMENT = MOMENT_OF_FORCE['aircraft']

PITCHING_MOMENT

PITCHING_MOMENT = AIRCRAFT_MOMENT['pitching']

Symbol: $M$

ROLLING_MOMENT

ROLLING_MOMENT = AIRCRAFT_MOMENT['rolling']

Symbol: $L$

YAWING_MOMENT

YAWING_MOMENT = AIRCRAFT_MOMENT['yawing']

Symbol: $N$

STATIC_MARGIN

STATIC_MARGIN = Dimensionless('static_margin')

Distance between the neutral point and the center of gravity, normalized by MAC.

Wikidata: Q7604177

Symbols: $K_n$, $SM$

$$K_n = \frac{x_{np} - x_{cg}}{\bar{c}}$$

$ K_n $

=

Static margin (dimensionless)

$ x_{np} $

=

Neutral point (meter)

$ x_{cg} $

=

Center of gravity (meter)

$ \bar{c} $

=

Mean aerodynamic chord (meter)

NEUTRAL_POINT

NEUTRAL_POINT = DISTANCE['neutral_point']

Longitudinal position of the aerodynamic center of the whole aircraft.

Symbol: $x_{np}$

CENTER_OF_GRAVITY

CENTER_OF_GRAVITY = DISTANCE['center_of_gravity']

Symbol: $x_{cg}$

TAIL_VOLUME_COEFFICIENT

TAIL_VOLUME_COEFFICIENT = Dimensionless(
    "tail_volume_coefficient"
)

HORIZONTAL_TAIL_VOLUME_COEFFICIENT

HORIZONTAL_TAIL_VOLUME_COEFFICIENT = (
    TAIL_VOLUME_COEFFICIENT["horizontal"]
)

Symbols: $C_{HT}$, $V_{HT}$

$$C_{HT} = \frac{L_{HT} S_{HT}}{\bar{c} S_w}$$

$ C_{HT} $

=

Horizontal tail volume coefficient (dimensionless)

$ L_{HT} $

=

horizontal tail moment arm (meter)

$ S_{HT} $

=

horizontal tail area (meter²)

$ \bar{c} $

=

Mean aerodynamic chord (meter)

$ S_w $

=

Wing area (meter²)

VERTICAL_TAIL_VOLUME_COEFFICIENT

VERTICAL_TAIL_VOLUME_COEFFICIENT = TAIL_VOLUME_COEFFICIENT[
    "vertical"
]

Symbols: $C_{VT}$, $V_{VT}$

$$C_{VT} = \frac{L_{VT} S_{VT}}{b S_w}$$

$ C_{VT} $

=

Vertical tail volume coefficient (dimensionless)

$ L_{VT} $

=

vertical tail moment arm (meter)

$ S_{VT} $

=

vertical tail area (meter²)

$ b $

=

Wingspan (meter)

$ S_w $

=

Wing area (meter²)

STATIC_TEMPERATURE

STATIC_TEMPERATURE = TEMPERATURE['static']

TOTAL_TEMPERATURE

TOTAL_TEMPERATURE = TEMPERATURE['total']

Also known as stagnation temperature.

CONST_TEMPERATURE_ISA

CONST_TEMPERATURE_ISA: Annotated[
    Decimal, STATIC_TEMPERATURE(K)
] = Decimal("288.15")

TEMPERATURE_DEVIATION_ISA

TEMPERATURE_DEVIATION_ISA = STATIC_TEMPERATURE[
    DELTA, OriginAt(Quantity(CONST_TEMPERATURE_ISA, K))
]

Deviation from the ISA temperature at sea level.

TOTAL_PRESSURE

TOTAL_PRESSURE = PRESSURE['total']

IMPACT_PRESSURE

IMPACT_PRESSURE = DYNAMIC_PRESSURE['impact']

PRESSURE_RATIO

PRESSURE_RATIO = Dimensionless('pressure_ratio')

Ratio of static pressure to standard sea level pressure.

TEMPERATURE_RATIO

TEMPERATURE_RATIO = Dimensionless('temperature_ratio')

Ratio of static temperature to standard sea level temperature.

DENSITY_RATIO

DENSITY_RATIO = Dimensionless('density_ratio')

Ratio of air density to standard sea level density.

AIRSPEED

AIRSPEED = QtyKind(M_PERS, ('airspeed',))

INDICATED_AIRSPEED

INDICATED_AIRSPEED = AIRSPEED['indicated']

Indicated airspeed (IAS), as measured directly from the pitot-static system.

CALIBRATED_AIRSPEED

CALIBRATED_AIRSPEED = AIRSPEED['calibrated']

Calibrated airspeed (CAS), IAS corrected for instrument and position errors.

EQUIVALENT_AIRSPEED

EQUIVALENT_AIRSPEED = AIRSPEED['equivalent']

Equivalent airspeed (EAS), CAS corrected for compressibility.

TRUE_AIRSPEED

TRUE_AIRSPEED = AIRSPEED['true']

True airspeed (TAS), speed relative to the airmass.

Symbol: $V$

GROUND_SPEED

GROUND_SPEED = AIRSPEED['ground']

Speed relative to the ground.

Symbol: $V_g$

STALL_SPEED

STALL_SPEED = AIRSPEED['stall']

APPROACH_SPEED

APPROACH_SPEED = AIRSPEED['approach']

TAKEOFF_SPEED

TAKEOFF_SPEED = AIRSPEED['takeoff']

ROTATE_SPEED

ROTATE_SPEED = AIRSPEED['rotate']

V1_SPEED

V1_SPEED = AIRSPEED['v1']

V2_SPEED

V2_SPEED = AIRSPEED['v2']

VREF_SPEED

VREF_SPEED = AIRSPEED['vref']

CORNER_SPEED

CORNER_SPEED = AIRSPEED['corner']

The speed at which the maximum lift coefficient and the maximum load factor are reached simultaneously.

Symbol: $V^*$

$$V^* = \sqrt{\frac{2 n_{\max} W}{\rho C_{L,\max} S}}$$

$ V^* $

=

Corner speed (meter · second⁻¹)

$ n_{\max} $

=

maximum load factor (dimensionless)

$ W $

=

Weight (newton)

$ \rho $

=

Density (kilogram · meter⁻³)

$ C_{L,\max} $

=

maximum lift coefficient (dimensionless)

$ S $

=

Wing area (meter²)

WIND_SPEED

WIND_SPEED = QtyKind(M_PERS, ('wind',))

Wind speed.

SPEED_OF_SOUND

SPEED_OF_SOUND = QtyKind(M_PERS, ('sound',))

Speed of sound.

FT_PER_MIN

FT_PER_MIN = FT * MIN ** -1

VERTICAL_RATE

VERTICAL_RATE = QtyKind(M_PERS, ('vertical_rate',))

Rate of climb or descent.

Commonly expressed in feet per minute.

Symbol: $VS$

VERTICAL_RATE_INERTIAL

VERTICAL_RATE_INERTIAL = VERTICAL_RATE['inertial']

Vertical rate derived from inertial sensors/GNSS.

VERTICAL_RATE_BAROMETRIC

VERTICAL_RATE_BAROMETRIC = VERTICAL_RATE['barometric']

Vertical rate derived from barometric pressure changes.

SPECIFIC_IMPULSE

SPECIFIC_IMPULSE = QtyKind(S, ('specific_impulse',))

RANGE

RANGE = DISTANCE['range']

TAKEOFF_DISTANCE

TAKEOFF_DISTANCE = DISTANCE['takeoff']

LANDING_DISTANCE

LANDING_DISTANCE = DISTANCE['landing']

TURN_RADIUS

TURN_RADIUS = DISTANCE['turn_radius']

Symbol: $R$

Assumptions: level coordinated turn$$R = \frac{V^2}{g\sqrt{n^2-1}}$$

$ R $

=

Turn radius (meter)

$ V $

=

True airspeed (meter · second⁻¹)

$ g $

=

Acceleration of free fall (meter · second⁻²)

$ n $

=

Load factor (dimensionless)

SHAFT_POWER

SHAFT_POWER = POWER['shaft']

Power delivered to a shaft (e.g. turboprop).

BRAKE_POWER

BRAKE_POWER = POWER['brake']

EQUIVALENT_SHAFT_POWER

EQUIVALENT_SHAFT_POWER = SHAFT_POWER['equivalent']

ENGINE_MASS_FLOW_RATE

ENGINE_MASS_FLOW_RATE = MASS_FLOW_RATE['engine']

KG_PERS

KG_PERS = KG * S ** -1

THRUST_SPECIFIC_FUEL_CONSUMPTION

THRUST_SPECIFIC_FUEL_CONSUMPTION = QtyKind(
    KG_PERS * N**-1, ("engine",)
)

Fuel mass flow rate per unit thrust.

Symbol: $TSFC$

POWER_SPECIFIC_FUEL_CONSUMPTION

POWER_SPECIFIC_FUEL_CONSUMPTION = QtyKind(
    KG_PERS * W**-1, ("engine", "power_specific")
)

Fuel mass flow rate per unit power.

FUEL_SPECIFIC_ENERGY

FUEL_SPECIFIC_ENERGY = SPECIFIC_ENERGY['fuel']

EXHAUST_VELOCITY

EXHAUST_VELOCITY = VELOCITY['exhaust']

BYPASS_RATIO

BYPASS_RATIO = Dimensionless('bypass_ratio')

PROPULSIVE_EFFICIENCY

PROPULSIVE_EFFICIENCY = Dimensionless(
    "efficiency_propulsive"
)

PROPELLER_EFFICIENCY

PROPELLER_EFFICIENCY = Dimensionless("efficiency_propeller")

ADVANCE_RATIO

ADVANCE_RATIO = Dimensionless('advance_ratio')

Ratio of freestream speed to tip speed for propellers.

Wikidata: Q4686098

Symbol: $J$

$$J = \frac{v}{n D}$$

$ J $

=

Advance ratio (dimensionless)

$ v $

=

Speed (meter · second⁻¹)

$ n $

=

Rotational frequency (n_revolutions · second⁻¹)

$ D $

=

Diameter (meter)

Aerodrome

Aerodrome(
    ident: str, ident_kind: Literal["icao", "iata"] | str
)

ident

ident: str

ident_kind

ident_kind: Literal['icao', 'iata'] | str

PRESSURE_ALTIMETER

PRESSURE_ALTIMETER = QtyKind(PA, ('altimeter',))

Altimeter setting (QNH/QFE).

RUNWAY_LENGTH

RUNWAY_LENGTH = QtyKind(M, ('runway', 'length'))

RUNWAY_VISUAL_RANGE

RUNWAY_VISUAL_RANGE = QtyKind(
    M, ("runway", "visual_range")
)

VISIBILITY

VISIBILITY = QtyKind(M, ('meteo', 'visibility'))

ICAO_ADDRESS

ICAO_ADDRESS = Dimensionless('icao_address_24_bit')

Unique 24-bit aircraft address assigned by ICAO.

SQUAWK_CODE

SQUAWK_CODE = Dimensionless('squawk_code_12_bit')

Mode A code (4 octal digits).

NAVIGATION_UNCERTAINTY_CATEGORY_POSITION

NAVIGATION_UNCERTAINTY_CATEGORY_POSITION = Dimensionless(
    "adsb_nucp"
)

NAVIGATION_UNCERTAINTY_CATEGORY_VELOCITY

NAVIGATION_UNCERTAINTY_CATEGORY_VELOCITY = Dimensionless(
    "adsb_nucv"
)

NAVIGATION_ACCURACY_CATEGORY_POSITION

NAVIGATION_ACCURACY_CATEGORY_POSITION = Dimensionless(
    "adsb_nacp"
)

NAVIGATION_ACCURACY_CATEGORY_VELOCITY

NAVIGATION_ACCURACY_CATEGORY_VELOCITY = Dimensionless(
    "adsb_nacv"
)

NAVIGATION_INTEGRITY_CATEGORY

NAVIGATION_INTEGRITY_CATEGORY = Dimensionless('adsb_nic')

SURVEILLANCE_INTEGRITY_LEVEL

SURVEILLANCE_INTEGRITY_LEVEL = Dimensionless('adsb_sil')