The airport JSON file must be in "assets/airports"; the filename should be icao.json where icao is the lowercase four-letter ICAO airport identifier, such as ksfo or kmsp. If this is a new airport, an entry must also be added to airportLoadList.js in alphabetical order. See the comments at the top of that file for information on the correct structure to use.
Note: The code block shown below is an abbreviated version of ksea.json.
{
"airac": 1801,
"radio": {
"twr": "Seatle Tower",
"app": "Seattle Approach",
"dep": "Seattle Departure"
},
"icao": "KSEA",
"iata": "SEA",
"magnetic_north": 16,
"ctr_radius": 110,
"ctr_ceiling": 15000,
"initial_alt": 15000,
"position": ["N47d26.99m0", "W122d18.71m0", "432ft"],
"rangeRings": {
"enabled": true,
"center": ["N47d26.99m0", "W122d18.71m0"],
"radius_nm": 5.0,
},
"has_terrain": true,
"wind": {
"angle": 150,
"speed": 9
},
"arrivalRunway": "16R",
"departureRunway": "16L",
"defaultMaps": ["Base Map"],
"airspace": [
{
"floor": 0,
"ceiling": 150,
"airspace_class": "B",
"poly": [
["N47.83333330", "W121.69999940"],
["N47.95335007", "W121.97603665"],
["N48.30000000", "W121.96666670"],
["N48.30000000", "W122.30000000"],
["N48.20000000", "W122.45000000"]
]
}
],
"fixes": {
"_NEZUG070010": ["N47d34.80m0", "W122d03.84m0"],
"_NEZUG070PAE139": ["N47d34.77m0", "W122d05.11m0"],
"_NICHY250SEA230": ["N47d19.92m0", "W122d42.78m0"],
"_OLM161026" : ["N46d32.31m0", "W122d54.11m0"],
"_SEA161002": ["N47d24.12m0", "W122d18.58m0"],
"_SEA341004": ["N47d30.12m0", "W122d18.58m0"],
"_SUMMA326017": ["N46d53.20m0", "W122d07.08m0"],
"AAYRR": ["N46d38.81m0", "W123d43.34m0"],
"BOANE": ["N47d59.10m0", "W122d43.52m0"],
"EUG" : ["N44d07.25m0", "W123d13.37m0"],
"FEPOT": ["N47d04.85m0", "W123d13.13m0"],
"GEG" : ["N47d33.90m0", "W117d37.61m0"],
"KRUZR": ["N48d04.65m0", "W120d34.68m0"],
"ONSET": ["N48d57.48m0", "W118d00.00m0"],
"PAE" : ["N47d55.19m0", "W122d16.67m0"],
"WESET": ["N47d24.35m0", "W122d19.10m0"],
"YXC" : ["N49d33.30m0", "W116d05.26m0"],
"ZUVEN": ["N47d47.98m0", "W122d25.15m0"]
},
"restricted": [
{
"name": "P-51",
"height": "2500ft",
"coordinates": [
["N47.7737128", "W122.7710456"],
["N47.7189169", "W122.7706794"],
["N47.6924411", "W122.7388044"],
["N47.6932556", "W122.6940508"],
["N47.7723906", "W122.6948667"]
]
}
],
"runways":[
{
"name": ["16L", "34R"],
"end": [
[47.463767, -122.307749, "432.5ft"],
[47.431201, -122.308035, "346.8ft"]
],
"ils": [true, true],
},
{
"name": ["16R", "34L"],
"end": [
[47.463806, -122.317884, "415.0ft"],
[47.440562, -122.318092, "356.3ft"]
],
"ils": [true, true],
}
],
"sids": {
"SUMMA1": {
"icao": "SUMMA1",
"name": "Summa One",
"altitude": 7000,
"rwy": {
"KSEA16L": ["NEVJO"],
"KSEA16R": ["NEVJO"],
"KSEA34L": [["NEZUG", "A40+"], "^_NEZUG070PAE139", "_SUMMA326017"],
"KSEA34R": [["NEZUG", "A40+"], "^_NEZUG070PAE139", "_SUMMA326017"]
},
"exitPoints": {
"BKE": ["SUMMA", "BKE"],
"LKV": ["SUMMA", "LKV"],
"SUMMA": ["SUMMA"]
},
"draw": [
["NEVJO", "SUMMA"],
["NEZUG", "_NEZUG070PAE139", "_SUMMA326017", "SUMMA"],
["SUMMA", "LKV*"],
["SUMMA*", "BKE*"]
]
}
},
"stars": {
"CHINS2": {
"icao": "CHINS2",
"name": "Chins Two",
"entryPoints": {
"CHINS": [],
"IMB": ["IMB", "SUNED", "YKM"],
"PDT": ["PDT", "BRUKK", "SUNED", "YKM"],
"SUNED": ["SUNED", "YKM"]
},
"body": ["CHINS"],
"rwy": {
"KSEA16L": [["RADDY", "A160+|S270"], ["HUMPP", "A150-"], ["AUBRN", "A120|S250"], "#343"],
"KSEA16R": [["RADDY", "A160+|S270"], ["HUMPP", "A150-"], ["AUBRN", "A120|S250"], "#343"],
"KSEA34L": [["RADDY", "A120|S250"], "HUMPP", "AUBRN", "#250"],
"KSEA34R": [["RADDY", "A120|S250"], "HUMPP", "AUBRN", "#250"]
},
"draw": [
["IMB*", "SUNED*", "YKM"],
["PDT*", "BRUKK", "SUNED", "YKM"],
["YKM", "CHINS*", "RADDY", "HUMPP", "AUBRN"]
]
}
},
"spawnPatterns": [
{
"origin": "KSEA",
"destination": "",
"category": "departure",
"route": "KSEA.SUMMA1.BKE",
"altitude": "",
"speed": "",
"method": "random",
"rate": 9,
"airlines": [
["aal", 4],
["aca", 1],
["asa", 3]
]
},
{
"origin": "",
"destination": "KSEA",
"category": "arrival",
"route": "PDT.CHINS2.KSEA",
"altitude": [18000, 36000],
"speed": 320,
"method": "random",
"rate": 15,
"airlines": [
["aal", 4],
["aca", 1],
["asa", 3]
]
},
{
"origin": "",
"destination": "",
"category": "overflight",
"route": "PDT..PSC..ELN..RADDY..AUBRN..GIGHR..ELMAA..HQM",
"altitude": [18000, 36000],
"speed": 320,
"method": "random",
"rate": 15,
"airlines": [
["aal", 4],
["aca", 1],
["asa", 3]
]
}
],
"maps": [
{
"name": "Base Map",
"lines": [
["N47.46706920", "W122.43465440", "N47.46816390", "W122.43651330"],
["N47.46635080", "W122.43369000", "N47.46706920", "W122.43465440"],
["N47.46975860", "W122.43977560", "N47.47109720", "W122.44296940"],
["N47.46816390", "W122.43651330", "N47.46975860", "W122.43977560"],
["N47.46549330", "W122.43386170", "N47.46635080", "W122.43369000"]
]
}
]
}All properties in this section are required
- airac ― AIRAC cycle from which data for the airport was taken. The airport must be fully compliant as of the specified cycle in order for this value to be changed.
- radio ― The radio callsigns for each controller:
"radio": {
"twr": "Seatle Tower",
"app": "Seattle Approach",
"dep": "Seattle Departure"
},- icao ― ICAO identifier of the airport. see ICAO identifiers for more information
- iata ― IATA identifier of the airport. see IATA identifiers for more information
- magnetic_north ― The magnetic declination (variation) of the airport. Declination is the angular difference between true north and magnetic north (in degrees EAST!) see this NOAA calculator if you can't find this value
- ctr_radius ― The radius (in kilometers) of the controlled airspace that aircraft are simulated within. Outside of this radius aircraft are removed, so ensure it is large enough for your airspace.
- ctr_ceiling ― The ceiling/top of the airspace (in feet). When an
airspaceproperty is present, that value will take priority over this one. - initial_alt ― The altitude (in feet) at which all departing aircraft are expected to stop their climb after takeoff unless otherwise instructed.
- position ― The geographical position of the airport. (in latitude, longitude, and elevation: see lat, lon, elev for formatting)
- rr_radius_nm ― (deprecated) Use rr.radius_nm instead.
- rr_center ― (deprecated) Use rr.center instead.
- rr.enabled ― Whether or not range rings will be shown for this airport
- rr.radius_nm ― The distance between each range ring (in nautical miles) within the airspace.
- rr.center ― The position at which the range rings are centered. (in latitude, longitude: see lat, lon, elev for formatting)
- has_terrain ― Flag used to determine if the airport has a corresponding
.geoJSONfile in assets/airports/terrain. - wind ― The true heading (angle) in degrees and speed in knots of the current wind at the airport:
"wind": {
"angle": 150,
"speed": 9
},- arrivalRunway ― The default runway to use for arrivals.
- departureRunway ― The default runway to use for departures.
- defaultMaps ― The names of the maps that should be rendered by default.
All properties in this section are required for each airspace section At least one airspace definition is required for an airport
"airspace": [
{
"floor": 0,
"ceiling": 150,
"airspace_class": "B",
"poly": [
["N47.83333330", "W121.69999940"],
["N47.95335007", "W121.97603665"],
["N48.30000000", "W121.96666670"],
["N48.30000000", "W122.30000000"],
["N48.20000000", "W122.45000000"]
]
}
],Position definition of the airport airspace. Multiple airspace areas may be defined and will all be included in the airspace. This allows for advanced airspace stratification.
- floor ― The lowest altitude (in flight levels) included in the airspace.
- ceiling ― The highest altitude (in flight levels) included in the airspace.
- airspace_class ― The FAA class of the airspace. For non-US airports, please review this FAA airspace classification document and find the closest match based on the way the local airspace is treated.
- poly ― The coordinates of the airspace. in latitude, longitude: see lat, lon, elev for formatting
All fixes listed within the Standard Routes need to be defined within this section
"fixes": {
"_NEZUG070010": ["N47d34.80m0", "W122d03.84m0"],
"_NEZUG070PAE139": ["N47d34.77m0", "W122d05.11m0"],
"_NICHY250SEA230": ["N47d19.92m0", "W122d42.78m0"],
"_OLM161026" : ["N46d32.31m0", "W122d54.11m0"],
"_SEA161002": ["N47d24.12m0", "W122d18.58m0"],
"_SEA341004": ["N47d30.12m0", "W122d18.58m0"],
"_SUMMA326017": ["N46d53.20m0", "W122d07.08m0"],
"AAYRR": ["N46d38.81m0", "W123d43.34m0"],
"BOANE": ["N47d59.10m0", "W122d43.52m0"],
"EUG" : ["N44d07.25m0", "W123d13.37m0"],
"FEPOT": ["N47d04.85m0", "W123d13.13m0"],
"GEG" : ["N47d33.90m0", "W117d37.61m0"],
"KRUZR": ["N48d04.65m0", "W120d34.68m0"],
"ONSET": ["N48d57.48m0", "W118d00.00m0"],
"PAE" : ["N47d55.19m0", "W122d16.67m0"],
"WESET": ["N47d24.35m0", "W122d19.10m0"],
"YXC" : ["N49d33.30m0", "W116d05.26m0"],
"ZUVEN": ["N47d47.98m0", "W122d25.15m0"]
},Each navaid located within or around the airport airspace in latitude, longitude: see lat, lon, elev for formatting. Real life fixes are defined thusly:
"AAYRR": ["N46d38.81m0", "W123d43.34m0"]You will notice in the list above there is a fix definition preprended with an _. This is called an invisible fix. A few examples of uses for these fixes include:
- To simulate DME arcs (can be seen in SAEZ)
- To simulate initial climbs (e.g. Climb runway heading until LON 2DME)
- To simulate radial intercepts (e.g. Intercept radial 180 to OLM)
They're used when we need aircraft to fly over a location that doesn't have an actual fix or waypoint. A fix should be created and should be named using the following conventions:
- Any fixes located at runway thresholds should be named after the runway at which they are located.
"_RWY33L": [42.354662, -70.991598]- Any fixes desired a given distance out from a given runway will be described via the distance from the threshold. This would be the runway whose approach path crosses the fix at the specified distance from the threshold (denoted in the fix name as a two digit distance in nautical miles, then "DME"). So a fix named
_RWY1805DMEwould be 5.0nm north of the landing threshold of Runway 18. All of these should be marked as invisible fixes (via the underscore prefix).
"_RWY33L01DME": [42.342838, -70.975751]- Any fixes that represent the intersection of a runway's inbound course and another course to a fix will be descried using the format below. Note that the runway whose approach course intersects is the one to be used, not the runway whose departure course intersects.
"_RWY12BSTER081": [25.810667, -80.322667]- Fixes may be defined based on the intersection of a runway's inbound course and an outbound radial of any fix. For a point aligned with Runway 33's approach path and the XYZ VOR's outbound radial 180, we get
_RWY33XYZ180. Note that if the intersection were to be on the departure side of a given runway, the opposite runway should be used to keep with the convention of using the approach course.
"_RWY1LPIE116": [27.848198, -82.546200]- Any fixes desired a given distance away from another fix will be described in fix-radial-distance form. This would be the fix name, three digit bearing, and three digit distance in nautical miles. All of these should be marked as invisible fixes (via the underscore prefix).
"_AUTUM220015": [42.324333, -71.736833]- Any fixes that represent the intersection of radials off of two fixes will be described by including each fix's outbound radial.
"_FIXXA030FIXXB180"- Fixes may be defined based on the intersection between outbound radials from two defined fixes. For a point northeast of
FIXXA, and northwest ofFIXXB, we could create_FIXXA050FIXXB320, where the three digit numbers after the fix names are the direction from that fix to the described location.
"_SIPLY233STINS324": [37.47860, -122.60090]- Fixes may be defined based on the intersection of a fix's outbound radial and the DME arc of the specified distance from a separate fix. This is formatted like
_FIXXA050FIXXB05DME, where the first fix has a three digit outbound radial, and the second fix has a two-digit distance in nm, followed by DME. Similarly, this can be done with runways using the same patterns as before, yielding_RWY22LFIXXB05DME; just use the name of the runway whose approach course intersects the DME arc, and not the departure path.
"_SEA104TCM40DME": [47.074500, -121.516167],
"_RWY16LPAE10DME": [47.754500, -122.308000]Areas of restricted airspace may be added to the restricted property of the airport file. This is an array containing restricted areas such as the example below:
"restricted": [
{
"name": "P-51",
"height": "2500ft",
"coordinates": [
["N47.7737128", "W122.7710456"],
["N47.7189169", "W122.7706794"],
["N47.6924411", "W122.7388044"],
["N47.6932556", "W122.6940508"],
["N47.7723906", "W122.6948667"]
]
}
],Note that height represents the top of the restricted area. Currently all restricted areas are assumed to begin at sea level.
"runways": [
{
"name": ["16L", "34R"],
"end": [
[47.463767, -122.307749, "432.5ft"],
[47.431201, -122.308035, "346.8ft"]
],
"ils": [false, true],
"ils_distance":[30, 25],
"loc_maxDist": [28, 20],
"glideslope": [3.00, 2.50]
}
],- name - Name of each runway in the pair. Names should reflect a 180 degree difference. so if one end if
"Runway 9"(or"Runway 09", depending on the country) the other runway should be"Runway 27". - end - Latitude, Longitude, and Elevation of the runway threshold (the spot where the numbers would be painted). see lat, lon, elev for formatting
- ils - Boolean property used to indicate if a runway has an ILS approach
- ils_distance - Distance the ILS extends away from the runway
- glideslope - Descent angle of the ILS glideslope
- loc_maxDist - Maximum distance from the runway threshold where the localizer is still usable by aircraft, in nm
- ils_gs_maxHeight - Maximum height where the glideslope is still usable by aircraft, in ft MSL
- sepFromAdjacent - A way to manually specify the separation required between this runway and an adjacent runway, in nm
Runways are defined in pairs because a runway can be used from either direction. This makes defining runways a little tricky, so special attention should be paid to how the data is set up. For each property, the first value will be considered part of the first runway and the second property for the second runway. If you were to take the above example and extract each runway's properties, you would end up with the following two objects:
// Runway 16L
{
"name": "16L",
"end": [
[47.463767, -122.307749, "432.5ft"]
],
"ils": false
}
// Runway 34R
{
"name": "34R",
"end": [
[47.431201, -122.308035, "346.8ft"]
],
"ils": true
}"airways": {
"J100": ["HEC", "CLARR", "LAS", "NORRA", "BCE"],
"J146": ["LAS", "NOOTN"],
"J9": ["HEC", "CLARR", "LAS", "NORRA", "AVERS", "URIAH", "BERYL", "MLF"],
"J92:" ["BTY", "BLD", "KADDY", "PRFUM", "CADDU", "DRK"],
"Q15": ["CHILY", "DOVEE", "BIKKR"],
"V8": ["PHYLI", "MMM", "MEADS", "ACLAM", "WINDS", "LYNSY", "SHUSS", "GFS", "HEC"]
},Each fix along each airway in successive order (direction does not matter). And of course, all fixes entered here must be defined in the fixes section.
Supported Instrument Procedures currently include only SIDs and STARs, and each contain three components:
- Entry - the starting point of the procedure (can include many different entry points)
- Body - shared segment that all aircraft on the route will follow
- Exit - the ending point of the procedure (can include many different exit points)
This structure is used to work with both SIDs and STARs within the app. Though it's not important to know for an airport file, it is a good thing to keep in mind.
Fixes within a segment might include an instruction and/or restrictions. Fixes can be defined in several different ways:
// fix name only
"16L": ["IMB", "SUNED", "YKM"]
// fix name with fly-over instruction
"16L": ["IMB", "^SUNED", "YKM"]
// fix name with holding instruction
"16L": ["IMB", "@SUNED", "YKM"]
// fix name with altitude restriction
"16L": ["IMB", ["SUNED", "A70"], "YKM"]
// fix name with speed restriction
"16L": ["IMB", ["SUNED", "S200"], "YKM"]
// fix name with at/below and at/above altitude and speed restrictions
"16L": ["IMB", ["SUNED", "A70+|S250-"], "YKM"]
// fix name with ranged altitude and speed restrictions
"16L": ["IMB", ["SUNED", "A70+|A100-|S210+|S250-"], "YKM"]These definitions can be used within any entryPoints, body or exitPoints segment of a procedure.
All properties in this section are required for each route definition
"sids": {
"SUMMA1": {
"icao": "SUMMA1",
"name": "Summa One",
"altitude": 7000,
"rwy": {
"KSEA16L": ["NEVJO"],
"KSEA16R": ["NEVJO"],
"KSEA34L": [["NEZUG", "A40+"], "^_NEZUG070PAE139", "_SUMMA326017"],
"KSEA34R": [["NEZUG", "A40+"], "^_NEZUG070PAE139", "_SUMMA326017"]
},
"body": [],
"exitPoints": {
"BKE": ["SUMMA", "BKE"],
"LKV": ["SUMMA", "LKV"],
"SUMMA": ["SUMMA"]
},
"draw": [
["NEVJO", "SUMMA"],
["NEZUG", "_NEZUG070PAE139", "_SUMMA326017", "SUMMA"],
["SUMMA", "LKV*"],
["SUMMA*", "BKE*"]
]
}
},SID is an acronym for Standard Instrument Departure.
- icao - icao identifier of the route, should match the object key in spelling and casing
"SUMMA1": {
"icao": "SUMMA1"
}- name - spoken name of the route used for read backs.
- altitude - (number) initial climb clearance (optional).
- rwy - (2d array of strings) considered the
Entry. Each key corresponds to a runway that can be used to enter the route. - body - (2d array of strings) fix names for the
Bodysegment. May be empty, but must be present. - exitPoints - (2d array of strings) considered the
Exit. Each key corresponds to and exit transition for a route. - draw - (2d array of strings) array of lines (arrays) to draw in blue between the listed fixes. The name of the SID will be displayed on top of the fix with a
*after it (e.g.["SUMMA", "LKV*"]). Please note that the 'draw' array must contain at least one array, even if it is empty:"draw": [[]]
Every possible rwy/body/exitPoint combination must result at least one fix. There must be at least one exitPoint, and it cannot be empty.
All properties in this section are required for each route definition
"stars": {
"CHINS2": {
"icao": "CHINS2",
"name": "Chins Two",
"entryPoints": {
"CHINS": [],
"IMB": ["IMB", "SUNED", "YKM"],
"PDT": ["PDT", "BRUKK", "SUNED", "YKM"],
"SUNED": ["SUNED", "YKM"]
},
"body": ["CHINS"],
"rwy": {
"KSEA16L": [["RADDY", "A160+|S270"], ["HUMPP", "A150-"], ["AUBRN", "A120|S250"], "#343"],
"KSEA16R": [["RADDY", "A160+|S270"], ["HUMPP", "A150-"], ["AUBRN", "A120|S250"], "#343"],
"KSEA34L": [["RADDY", "A120|S250"], "HUMPP", "AUBRN", "#250"],
"KSEA34R": [["RADDY", "A120|S250"], "HUMPP", "AUBRN", "#250"]
},
"draw": [
["IMB*", "SUNED*", "YKM"],
["PDT*", "BRUKK", "SUNED", "YKM"],
["YKM", "CHINS*", "RADDY", "HUMPP", "AUBRN"]
]
}
},STAR is an acronym for Standard Terminal Arrival Route.
- icao - icao identifier of the route, should match the object key in spelling and casing
"CHINS2": {
"icao": "CHINS2"
}- name - spoken name of the route used for read backs.
- entryPoints - (2d array of strings) considered the
Entry. Each key corresponds to a route transition that can be used to enter the route. - body - (2d array of strings) fix names for the
Bodysegment. May be empty, but must be present. - rwy - (2d array of strings) considered the
Exit. Each key corresponds to a runway that is usable from this route - draw - (2d array of strings) array of lines (arrays) to draw in red between the listed fixes. The name of the STAR will be displayed on top of the fix with a
*after it (e.g.["PDT*", "BRUKK"])
At least one spawnPattern is required to get aircraft populating into the app
"spawnPatterns": [
{
"origin": "KSEA",
"destination": "",
"category": "departure",
"route": "KSEA.SUMMA1.BKE",
"altitude": "",
"speed": "",
"method": "random",
"rate": 9,
"airlines": [
["aal", 4],
["aca", 1],
["asa", 3]
]
},
{
"origin": "",
"destination": "KSEA",
"category": "arrival",
"route": "PDT.CHINS2.KSEA",
"altitude": [18000, 36000],
"speed": 320,
"method": "random",
"rate": 15,
"airlines": [
["aal", 4],
["aca", 1],
["asa", 3]
]
},
{
"origin": "",
"destination": "",
"category": "overflight",
"route": "PDT..PSC..ELN..RADDY..AUBRN..GIGHR..ELMAA..HQM",
"altitude": [18000, 36000],
"speed": 320,
"method": "random",
"rate": 15,
"airlines": [
["aal", 4],
["aca", 1],
["asa", 3]
]
}
],Contains the parameters used to determine how and where aircraft are spawned into the simulation. At least one spawnPattern is required so that aircraft can be added to the simulation.
see spawnPatternReadme.md for more detailed descriptions on data shape and format of a spawnPattern
At least one map is required for the airport to be loaded into the simulation. In addition to the maps, a defaultMaps property is required to have at least one name referenced. An maps not listed in defaultMaps will not be rendered by default.
"maps": [
{
"name": "Base Map",
"lines": [
["N47.46706920", "W122.43465440", "N47.46816390", "W122.43651330"],
["N47.46635080", "W122.43369000", "N47.46706920", "W122.43465440"],
["N47.46975860", "W122.43977560", "N47.47109720", "W122.44296940"],
["N47.46816390", "W122.43651330", "N47.46975860", "W122.43977560"],
["N47.46549330", "W122.43386170", "N47.46635080", "W122.43369000"]
]
}
]Markings on the scope that depict various characteristics of the airspace. When available, this will be an actual Radar Video Map used by the real-world facility.
For lat, lon, elev values, these formats are acceptable:
- [40.94684722, -76.61727778, "866ft"]
- ["N40.94684722", "W76.61727778", "866ft"]
- ["N40d56.811", "W076d37.037", "866ft"]
- ["N40d56m48.65", "W076d37m02.20", "866ft"]
Note: For lat, lon values, just omit the elevation.
Identifiers are unique codes used to differentiate airports, fixes, aircraft, etc. (ex: "KSFO" for the San Francisco Airport). ICAO (the International Civil Aviation Organization) is an international aviation authority that sets safety and consistency standards that make worldwide travel more standardized. ICAO maintains many lists of things they assign their own identifiers (such as aircraft type designators, airport identifiers, etc). Wherever we have those identifiers stored, they will have the label "icao".
IATA is another international aviation organization (like ICAO) which maintains their own set of identifiers. We include the IATA identifiers for airports in all airport .json files, though they are not currently used for anything.
Flight levels are described by a number, which is this nominal altitude (or, pressure altitude) in hecto-feet, while being a multiple of 500 ft, therefore always ending on 0 or 5. Therefore, a pressure altitude of, for example, 32,000 feet is referred to as "flight level 320".
Flight levels are usually designated in writing as FLxxx, where xxx is a two or three-digit number indicating the pressure altitude in units of 100 feet. In radio communications, FL290 would be pronounced as "flight level two nine(r) zero." The phrase "flight level" makes it clear that this refers to the standardized pressure altitude.