FSDS: Definitions of Variables

The following definitions define the fields in FSDS reports:

• All Passenger. Any non-freight aircraft.
• Air Carrier. (AC) Aircraft with seating capacity of more than 60 seats, carrying passengers for hire or compensation. This includes US and foreign-flagged carriers.
• Arrival. Code of arrival airport and city of departure.
• Arrival Airport. Three- or four-character code identifying the arrival airport.
• Arrival Airport Type. Type of airport of arrival: Full Radar Tower, Limited Radar Tower.
• Arrival Count. Number of arrivals per airport, state, region, or country.
• Arrival Country. Four-position numeric field identifying the destination country of this flight. Position 4 is a constant zero and refers to world area code.
• Arrival Hour. Number from 0-24 representing the hour of scheduled arrival.
• Arrival Hub Size. Hub size of arrival airport.
• Arrival Quarter Hour. Number from 1-4 representing the quarter hour of scheduled arrival.
• Arrival Region. FAA Region based on the Arrival field.
• Arrival Time. Local time of gate arrival at the destination airport expressed by the 24-hour clock. Hours expressed as 0000 and 2400 are invalid in this field and are entered as 0001. FLAG and FUEL are also valid and indicate flag or fuel stops.
• ATC Commuter. A passenger aircraft whose configuration is between 1 and 60 seats.
• Block. Elapsed time from departure gate to arrival gate, in minutes.
• Block Hours. Elapsed time from departure gate to arrival gate, in hours and minutes.
• Block Hours Per Flight. Elapsed time from departure gate to arrival gate in minutes for a specific flight.
• Business Jet. A jet aircraft owned by a single or a group of individuals/corporations, and which is usually not operated in a schedule.
• Carrier Type. Indicator that the operating carrier is domestic or foreign as determined by APO-100.
• Departure. Code of departure airport and/or city of departure.
• Departure Airport. Three-character location identifier and city name.
• Departure Airport Type. Type of airport of departure: Full Radar Tower, Limited Radar Tower.
• Departure Count. Number of departures per airport, state, region, or country.
• Departure Country. Country name based on the Departure field.
• Departure Hub Size. Hub size of departure airport.
• Departure Hour. Number from 0-24 representing the hour of scheduled departure.
• Departure Quarter Hour. Number from 1-4 representing the quarter hour of scheduled departure.
• Departure Region. FAA Region based on the Departure field.
• Departure Time. Local time of gate departure expressed by the 24-hour clock. Hours expressed as 0000 and 2400 are invalid and are entered as 0001. FLAG and FUEL are also valid and indicate flag or fuel stops.
• Equipment. IATA equipment code and APO-100 provided name.
• Equipment Class. Aircraft are divided into categories related to impact on wake turbulence: (1) heavy (any aircraft weighing more than 255,000 lb such as the Boeing 747 or the Airbus A340); (2) B757 for Boeing 757 all series; (3) large jet (large jet aircraft weighing more than 41,000 and up to 255,000 lbs such as the Boeing 737 or the Airbus A320); (4) large commuter (large commuter aircraft including small regional jets weighing more than 41,000 and up to 255,000 lbs such as the Aerospatiale/Alenia ATR-42 , the Bombardier Canadair Regional Jet, or the Saab SF 340); (5) medium (small commuter aircraft including business jets weighing more than 12,500 up to 41,000 lbs such as the Embraer 120 or the Learjet 35); and (6) small equipment (small, single, or twin engine aircraft weighing 12,500 lbs or less such as the Beech 90 or the Cessna Caravan). Unknown refers to unspecified equipment.
• Facility. Three-letter code identifying the facility.
• Flight. The number identifying the flight as assigned by the air carrier. Permissible values: 1–9999.
• Flight Type. Derived from city pair country codes to indicate flight direction. Permitted variables are: Domestic (both arrival and departure are in the US), US to Foreign, Foreign to US, and Foreign (both arrival and departure are in a foreign country).
• Flights. Number of flights between a City Pair.
• Freight. Any air carrier operating equipment with no revenue seats.
• Hours. One-hour intervals used to sort flight counts.
• Hub Size. Classification of Hub Size is based on the percentage of total US enplaned revenue passengers per year.

Large Hub	1% of US Enplanements or more
Medium Hub	less than 1% but more than 1/4%
Small Hub	less than 1/4% but greater than .05%
Non Hub	less than .05% of US Enplanements

• Majors. YES/NO indicator to denote major air carriers. Majors is a U.S. designation for an air carrier with annual operating revenue of more than one billion dollars, such as American, Delta, and United Airlines. Also called major carrier.
• Operator Carrier. Three-letter code and name of carrier providing the service.
• Regional Jet. A commercial jet aircraft carrying fewer than 100 passengers (i.e., Embraer 190 or Bombardier CRJ-200).
• Operator Carrier Type. Type of operating carrier determined by APO-100 as domestic or foreign.
• Seat Miles (000). The number of Seats times the Statute Miles Per Flight, divided by 1,000.
• Seats. The number of seats for a specific type of aircraft may vary depending on the region of operation. For example, a Continental 757-200 flying between Newark (EWR) and Birmingham, England (BHX) will have 172 seats, whereas a Continental 752-200 flying between Newark (EWR) and Houston (IAH) will have 183 seats. This local flight concept includes the US and nearby destinations (Canada, Mexico, and the Caribbean).
• Seats Per Flight. Number of seats for a specific flight.
• Seller Carrier. Three-letter code and name of carrier selling the ticket.
• Service Type. Indicates rotary (helicopter) or fixed-wing aircraft (jet, piston, turbine) through the following: Jet, Propeller, Turbo Prop, and Helicopter.
• Statute Miles (Airport view). Miles calculated from lat/long of airports.
• Statute Miles (City Pair view). Distance between city pairs in statute miles. This is the calculated great circle route between the latitude and longitude of the city pairs, converted from nautical to statute miles.
• Statute Miles Per Flight. Distance between city pairs for a specific flight, expressed in statute miles.
• Total Base. Number of operations occurred in the set of dates selected in the 'Dates' section.
• Total Comparison. Number of operations occurred in the set of dates selected in the 'Output/Comparison Report' section.
• Total Difference. Difference between comparison and base operations.
• User Class. User classes are groups of aircraft based on the equipment reported: Air Carrier, ATC Commuter, Freight, and All-Passenger. All-Passenger is a combination field including Air Carrier and ATC Commuter (all flights by non-freigh aircraft).