This refers either to the departure airport or a world region. For an airport, data are displayed as a three-letter code (IATA-International Air Transport Association- code). For world regions, codes used in Back Aviation are described in Table 5.
Table 5: World regions code system used in Back Aviation database.
World Regions  Code System 
Africa  .AFR 
Australasia & Oceania  .AUS 
Canada  .CAN 
Caribbean  .CARIB 
Central America  .CAMER 
Europe  .EUR 
Far East  .FEAST 
Greenland  .GREEN 
Middle East  .MEAST 
South America  .SAMER 
USA  .USA 

EQUIPMENT

This refers to the aircraft type used for a flight; it is represented by a three-character code. As only aircraft equipments are wanted, the constraint was set up to “not equal to .R .A” (Erreur ! Source du renvoi introuvable.).
Table 6: Equipment type code system used in Back Aviation database.
Code  Classification 
.A  Amphibious vehicles (includes hovercrafts, launches) 
.H  Helicopters 
.J  Jets 
.P  Props 
.R  Road vehicles (includes buses, limousines, trains) 
.T  Turboprops 

SERVICE-FARE CLASS

This refers to the type of flight, such as Jet-First Class or Jet-Coach. A flight can be either passenger or cargo, or both. This distinction depends on whether the flight is listed in the passenger edition or cargo edition of the OAG publications. If a plane carries both passengers and cargo, it will be listed twice in the BACK OAG database, once as a passenger flight with a passenger service class and once as a cargo flight with a fare/service class of 2, 3, or 4. Codes A to Z designate passenger flights. Code 1 designates cargo. Codes 2 to 4 represent cargo flights, which carry passengers. To avoid double accounting of flights which are both passenger and cargo, the default constraint for this code specifies codes not equal to “2, 3, 4” which represent both passenger and cargo flights.
4.3. Display information
Once the constraints were set up, fields to extract were selected (Table 7) and a complete set of schedules was extracted for the time period selected. Additional fields not mentioned in the constraint paragraph are explained below Table 7.
Table 7: Fields extracted from Back Aviation database and displayed.
FIELDS  EXAMPLE 
Origin  AAL 
Destination  BLL 
Published carrier  DM 
Equipment type  735 
Great Circle distance (nm)  98 
Flight number  41 
Departure time  6:40 
Arrival time  7:10 
Days of operation  1 56 
Elapsed time  10 
20011004  0 
20011005  1 
20011006  1 

DESTINATION
Destination is the airport of arrival shown as a three-letter airport code (IATA code).
PUBLISHED CARRIER
Published carrier refers to the airline represented by a two-character code. Codes containing decimals and numbers after the two characters (e.g., AB.1) designate airlines, which are no longer filing schedules with the OAG. However, some codes will have four characters (e.g., A100). The published carrier associated to the flight number forms the callsign.
GREAT CIRCLE DISTANCE (NM)
This field represents the distance in nautical miles (nm) between any two airports, using the latitude and longitude of each airport, and the Great Circle line The Great Circle (GC) is the shortest line that passes through two points on a sphere’s surface.
FLIGHT NUMBER
This field is an identification number assigned to a flight. 
　
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