ASPM: Individual Flights: Definitions of Variables

The following definitions define the fields in the ASPM reports of Individual Flights:

• ACID. The airline and flight number as identified by TFMS. The airline code typically identifies the operating carrier.
• Actual Airborne Time. The difference between Actual Wheels On and Actual Wheels Off, in minutes.
• Actual Arrival Date. Local date of arrival. MM/DD/YYYY.
• Actual Block Time. The difference between Actual Gate In and Actual Gate Out, in minutes.
• Actual Departure Date. Local date of departure. MM/DD/YYYY.
• Actual Gate In. The time an aircraft arrived at the gate. This variable is provided by OOOI data from ASQP, ARINC, or TFMS (starting FY15) and is estimated for all other flights that do not have OOOI data. See ASPM: Estimation Techniques.
• Actual Gate Out. The time an aircraft departed from the gate. This variable is provided by OOOI data from ASQP, ARINC, or TFMS (starting FY15) and is estimated for all other flights that do not that do not have OOOI data. See ASPM: Estimation Techniques.
• Actual Wheels Off. The time an aircraft takes off. The Actual Wheels Off time is provided for many carriers by ASQP, ARINC, or TFMS (starting FY15), or by CountOps for most other flights; otherwise it is estimated from the DZ message. See ASPM: Estimation Techniques.
• Actual Wheels On. The actual time an aircraft lands on the runway. The Actual Wheels On Time is provided for many carriers by ASQP, ARINC, or TFMS (starting FY15), or by CountOps for most other flights; otherwise it is estimated from the AZ message. See ASPM: Estimation Techniques.
• Airborne Delay. Amount of delay caused by airborne holding, in minutes.
• Airborne Time Difference. The difference between Actual Airborne Time and Estimated Time Enroute, in minutes. Difference may be positive or negative.
• Airport Departure Delay (Flight Plan). Estimated delay derived from the Actual Wheels Off minus the Flight Plan Gate Out plus the Unimpeded Taxi Out time, in minutes. Negative values contribute to the value if the report has “Include Early Flights” checkbox selected on the Filters tab.
• Airport Departure Delay (Schedule). The Actual Wheels Off minus the Scheduled Gate Out plus the Unimpeded Taxi Out time, in minutes. Negative values contribute to the value if the report has “Include Early Flights” checkbox selected on the Filters tab.
• Airport Departure Difference (Flight Plan). The difference between Actual Wheels Off and Flight Plan Wheels Off, in minutes. Difference may be positive or negative.
• Airport Departure Difference (Schedule). The difference between Actual Wheels Off and Scheduled Wheels Off, in minutes. Difference may be positive or negative.
• ARINC Present. Indicates whether the flight record was constructed using an ARINC record containing Out, Off, On, In times for the particular flight.
• Arrival Airport. Three- or four-letter code identifying the arrival airport.
• ASQP Reported Carrier Delay. The number of minutes of delay specifically due to the carrier, for flights that arrived 15 minutes or more past the scheduled arrival time.
• ASQP Reported Late Arrival Delay. The number of minutes of delay specifically due to the late arrival of a previous flight with the same aircraft, for flights that arrived 15 minutes or more past the scheduled arrival time.
• ASQP Reported NAS Delay. The number of minutes of delay specifically due to the NAS, for flights that arrived 15 minutes or more past the scheduled arrival time.
• ASQP Reported Security Delay. The number of minutes of delay specifically due to security for flights that arrived 15 minutes or more past the scheduled arrival time.
• ASQP Reported Weather Delay. The number of minutes of delay specifically due to weather for flights that arrived 15 minutes or more past the scheduled arrival time.
• AZ. Arrival message time sent by ERAM to ETMS when a flight is completed.
• Block Delay. The difference between Actual Block Time and Scheduled Block Time, in minutes.
• Block Time Difference. The difference between Actual Gate-To-Gate time and Scheduled Gate-To-Gate time, in minutes. Difference may be negative or positive.
• Calculated Block Buffer. The difference between Scheduled Block Time and Optimal Block Time.
• Carrier (or Carrier Code) Three-letter code identifying the carrier. Historically the carrier code was determined by its primary data source (ASQP or other OOOI source where available, otherwise TFMS), and while most records listed the carrier that operated the flight, some flights operated by regional/sub-carriers were listed under the carrier that sold the ticket. Starting in 2017, ASPM transitioned to reporting the operating carrier in this field, and added a separate field to identify the selling carrier.
• CountOps Arrival ACID. The airline and flight number of the arrival flight.
• CountOps Arrival Present. A Yes/No field indicating whether a CountOps record was located for this arrival.
• CountOps Arrival Runway. The arrival runway number recorded on the CountOps record, if provided.
• CountOps Departure ACID. The airline and flight number of the departure flight.
• CountOps Departure Present. A Yes/No field indicating whether a CountOps record was located for this departure.
• CountOps Departure Runway. The departure runway number recorded on the CountOps record, if provided.
• Departure Airport. Three- or four-letter code identifying the departure airport.
• Departure Date. Date of departure of selected flight.
• DZ. Departure message time sent by ERAM to ETMS when a flight is activated.
• EDCT Arrival Delay. Actual Wheels On Time minus the EDCT specified Wheels On Time, in minutes, for flights with a departure delay caused by EDCT. The value may be negative.
• EDCT Departure Delay. The Estimated Departure Clearance Time (EDCT) Departure Delay is an estimate of the airport departure delay due to a traffic management initiative (TMI) requiring aircraft to be held on the ground at the departure airport. Through September 2011, the EDCT Departure Delay was calculated as the EDCT Wheels Off time minus the FAA Planned Wheels Off time, in minutes. Starting October 2011, the calculation was modified to: The lesser of 1) The difference between the EDCT Off Time and the earlier of the FAA Planned Wheels Off or the Scheduled Airport Departure Time (Scheduled Gate Out + Unimpeded Taxi Time); and 2) The difference between the EDCT Off Time and the Flight Plan Airport Departure Time (the carrier filed flight plan time + the Unimpeded Taxi Time). Calculation 1) provides an upper limit on EDCT Departure Delays, and reduces the reliance on the FAA Planned Wheels Off Time. Calculation 2) generally results in a smaller EDCT Departure Delay, and is applied to the flights with EDCTs in most cases. The calculation was changed due to an unexplained shift in the FAA Planned Wheels Off Time that resulted in lower than expected EDCT Departure Delays. EDCT Departure Delay is capped by the Airport Departure Delay.
• EDCT Wheels Off. The runway release time assigned based on Expect Departure Clearance Time (EDCT).
• EDCT Wheels On. The runway arrival time assigned based on Expect Departure Clearance Time (EDCT).
• Estimated Time Enroute. The flight plan filed ETE (Estimated Time Enroute) is the planned airborne time, in minutes.
• ETMS (All, Yes, No). Filter option indicating whether the ASPM record was constructed utilizing an ETMS record. A record marked Y (YES) indicates a flight plan exists; a DZ and an AZ time are likely to be present.
• Aircraft Type. ETMS Aircraft Type designator. This is usually a three- or four-character field extracted from an ETMS flight plan or from an available ASQP record.
• ETMS Planned Wheels Off. ETMS modeled Wheels Off time provided by ETMS (TFMS).
• ETMS Present. The ETMS Present field is marked Y (Yes) or N (No). A record marked Y (YES) indicates that the flight record was constructed utilizing an ETMS record, which is the source for some or all flight plan data (gate departure, ETE), and DZ and AZ data. If an ETMS record was not used, then flight plan times and DZ and AZ times are estimated.
• Flight Index. One component of the ETMS primary key provided by NAS Data Warehouse.
• Flight Number. The number identifying the flight as assigned by the air carrier. Permissible values: 1–9999.
• Flight Plan Gate In. Calculated initially as the Filed PTime (Gate Out Time specified in the flight plan if ETMS is present) plus Unimpeded Taxi Out plus Filed ETE plus Unimpeded Taxi In. When a flight's Filed PTime is greater than the Scheduled Departure Time, ASPM adjusts the Planned Gate Out by setting it to the Filed PTime. Then, ASPM adjusts the Planned Gate In by using the adjusted planned departure time. These adjustments used to calculate delays are based on the last filed flight plan before departure.
• Flight Plan Gate Out. Gate Out Time specified in the flight plan if ETMS is present (Filed PTime), or the Scheduled Departure time from schedule or ASQP. The last filed flight plan before departure is used in ASPM.
• Flight Plan Wheels Off. The estimated wheels off time, calculated as the Flight Plan Gate Out time (Filed PTime) from ETMS (TFMS), plus estimated unimpeded taxi out time.
• Flight Type (Domestic Flight, US to Foreign, Foreign to US, Foreign Flight). Filter option indicating 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).
• Gap AZ. The difference between Wheels On Time and AZ message time, generally ranging from 1 minute to 10 minutes. This value is measured when both ETMS Present = Y and OOOI Present = Y. Observed values from OOOI records are used to calculate the median times (by day, by airport, by hour) for substitution if AZ Time is missing or Wheels On Time is missing.
• Gap DZ. The difference between DZ message time and Wheels Off Time, generally about 1 minute. This time is measured when both ETMS Present = Y and OOOI Present = Y. Observed values are used to calculate the median times (by day, by location, by hour) for substitution of the Wheels Off Times in other records.
• Gate Arrival Delay (Flight Plan). The difference between the Actual Gate In time and the Flight Plan Gate In time for late arrivals of 1 minute or more.
• Gate Arrival Delay (Scheduled). The difference between the Actual Gate In time and the Scheduled Gate In time, for late arrivals of 1 minute or more.
• Gate Arrival Difference (Flight Plan). The difference between the Actual Gate In time and the Flight Plan Gate In time, in minutes. Difference may be negative or positive.
• Gate Arrival Difference (Schedule). The difference between the Actual Gate In time and the Scheduled Gate In time, in minutes. Difference may be negative or positive.
• Gate Departure Delay (Flight Plan). The difference between the Actual Gate Out time and the filed Flight Plan Gate Out (PTime) time, in minutes. Negative Gate Departure Delay values are not allowed, so early departure plus a Taxi Out Delay may result in an on-time Wheels Off Time.
• Gate Departure Delay (Scheduled). The difference between the Actual Gate Out time and the Scheduled Gate Out time, in minutes. Negative Gate Departure Delay values are not allowed, so early departure plus a Taxi Out Delay may result in an on-time Wheels Off Time.
• Gate Departure Difference (Flight Plan). The difference between Actual Gate Out time and Flight Plan Gate Out. Difference may be positive or negative.
• Gate Departure Difference (Scheduled). The difference between Actual Gate Out time and Scheduled Gate Out. Difference may be positive or negative.
• Gate Departure Difference Scheduled. The difference between Actual Gate Out time and Scheduled Gate Out. Difference may be positive or negative.
• Local Arrival Hour. One-hour interval in which selected flight landed (minutes are not included).
• OAG Present. The OAG Present field is marked Y (Yes) or N (No). A record marked Y (YES) indicates that the flight record was constructed utilizing an OAG record.
• Oceanic. A flight that crosses an ocean and generates "TO" messages. Oceanic flights must have values for all fields in the record to be used for metric computation. Incomplete flight records are not used for metric computation, but are included in Efficiency Counts at airports. As a filter option, it indicates enroute IFR or overflights that cross oceanic airspace. (All/Yes/No).
• OOOI (All, Yes, No, ARINC Only, ASQP Only). Filter option indicating whether actual OOOI data contained in an ASQP, ARINC, or TFMS record was used to construct the ASPM record.
• OOOI Present. This variable is marked Y (YES) or N (NO). It indicates whether actual OOOI data contained in an ASQP, ARINC, or TFMS record was used to construct the ASPM record. When N, Actual Gate Out, and Actual Gate In times are estimated, and Actual Wheels Off and Actual Wheels On times are estimated for flights without a CountOps record. See ASPM: Estimation Techniques.
• OPSNET Delay Cause. For flights that show an ASQP Reported NAS Delay, the most dominant OPSNET delay cause (Weather, Volume, Equipment, Runway, and Other) that matches that ASQP flight.
• Optimal Block Time. The sum of Unimpeded Taxi Out time, Filed Estimated Time Enroute, and Unimpeded Taxi In time.
• Physical Class (All, Turbine, Jet, Piston, Helicopter, Other). Categories of aircraft engines.
• Schedule Present. This field is marked Y (YES) or N (NO). When Y, it indicates that the flight was listed in a published schedule or the Customer Reservation System (CRS). When N, scheduled arrival and departure times are derived from the flight plan.
• Scheduled Block Time. The difference between Scheduled Gate In and Scheduled Gate Out, in minutes.
• Scheduled Departure Date. Scheduled Departure Date observed using local clock time at a particular location.
• Scheduled Flights (All, Yes, No). Filter option indicating flights listed in a published schedule.
• Scheduled Gate In. Observed from the schedule, otherwise calculated from the ETMS Flight Plan using the formula: Flight Plan Gate Out time plus Unimpeded Taxi Out plus Flight Plan Expected Time Enroute plus Unimpeded Taxi In.
• Scheduled Gate Out. Scheduled Gate Out from the schedule or ASQP, when available, otherwise is set to the ETMS Flight Plan Filed PTime.
• Scheduled Wheels Off. Estimated by adding the Scheduled Gate Out time to the Unimpeded Taxi Out times.
• Selling Carrier. Carrier selling tickets for a flight. The flight may have been operated by a different airline.
• Tail Number. Aircraft identification number located on the tail of the aircraft (for most GA traffic) or carrier code plus flight number.
• Taxi In Delay. Actual Taxi In Time minus Unimpeded Taxi In Time. Taxi In Delay may occur when a gate is not available for an arriving aircraft. Negative values are allowed if the report includes early flights.
• Taxi In Time. The Taxi In Time in minutes is either observed or estimated. See ASPM: Estimation Techniques.
• Taxi In Time Difference. The time between Actual Wheels On and Actual Gate In time, in minutes. May be negative or positive.
• Taxi Out Delay. Taxi Out delay greater than 1 hour.
• Taxi Out Time. The difference between Actual Gate Out time and Actual Wheels Off time, in minutes. The value is observed for flights for which OOOI data are available, otherwise it is estimated. See ASPM: Estimation Techniques.
• Taxi Out Time Difference. The difference between Taxi Out Time and Unimpeded Taxi Out time (by airport, carrier, season). Difference may be positive or negative.
• Unimpeded Taxi In Time. The estimated Taxi In Time for an aircraft by carrier under optimal operating conditions (when congestion, weather, or other delay factors are not significant). See ASPM: Estimation Techniques.
• Unimpeded Taxi Out Time. The estimated Taxi Out Time for an aircraft by carrier under optimal operating conditions (when congestion, weather, or other delay factors are not significant). See ASPM: Estimation Techniques.
• User Class. Air Carrier, Freight, Air Taxi, General Aviation, and Military. User classes are designations assigned by the Volpe Center based on the equipment reported.