ASPM Efficiency: Definitions of Variables

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The following definitions define the fields in the ASPM reports of Airport Efficiency:

  • % Arrival Demand Mod+Sev Weather. The percent of arrival demand units during periods in which the weather was classified as moderate or severe based on the ASPM weather factors methodology. If there was no moderate or severe weather during the timeframe specified, or if there was no arrival demand during the periods of moderate or severe weather, the reported value is zero. The % Hours Mod+Sev Weather field can be used to distinguish between those two situations. The Weather Factors methodology categorizes and reports on the severity of a combination of weather factors (wind speed, ceiling, visibility, nearby thunderstorms, en route thunderstorms, and airport weather such as rain and snow) in terms of their impact on flight delays. For more information on Weather Factors, see the ASPM Weather Factors Manual.
  • % Arrivals Mod+Sev Weather. The percent of arrivals during periods in which the weather was classified as Moderate or Severe based on the ASPM weather factors methodology. If there was no moderate or severe weather during the timeframe specified, or if there were no arrivals during the periods of moderate or severe weather, the reported value is zero. The % Hours Mod+Sev Weather field can be used to distinguish between those two situations. The Weather Factors methodology categorizes and reports on the severity of a combination of weather factors (wind speed, ceiling, visibility, nearby thunderstorms, en route thunderstorms, and airport weather such as rain and snow) in terms of their impact on flight delays. For more information on Weather Factors, see the ASPM Weather Factors Manual.
  • % Arrivals with OOOI. The percent of arrivals with Out, Off, On, and In times from ARINC, TFMS, or ASQP.
  • % Arrivals with CountOps. The percent of ASPM arrivals for which a CountOps record was matched to the original ASPM record. Arrivals with CountOps have actual On and Off times from the CountOps Runway Threshold Crossing Time, or other OOOI sources.
  • % Capacity Utilized (System Perspective). The sum of Arrivals and Departures for Efficiency Computation divided by the sum of the ADR and the Capacity AAR, multiplied by 100. Displayed on the System Efficiency Standard Report, System Perspective.
  • % ETA Calculation (% ETA Calc). The ETA Calculation divided by the Arrivals for Efficiency Computation, multiplied by 100. A value lower than 100% indicates that some flights had incomplete circle crossing times and could not be used for calculating the TAER. A value greater than 100% indicates that some flights had sufficient circle data for calculating the TAER, but were not included in Arrivals for Efficiency Calculations due to problems with other key data fields.
  • % Hours Mod+Sev Weather. The percent of hours during the time period specified in which the weather was classified as Moderate or Severe based on the ASPM weather factors methodology.
  • 100 Mile Crossing Time. The Universal Time Coordinate (UTC) or (GMT) time when a flight leaves the 100-mile segment.
  • 20% of Flights. The number of flights comprising the 20% of Total Flights used for calculating TAER means.
  • 40-Mile Approach Angle. The direction from the arrival airport in degrees of true north when the flight is 40 miles from the airport.
  • AAR (Airport Arrival Rate). The facility determined arrival rate that it can handle given the current weather conditions, traffic mix, and runway configuration. Facilities update the arrival rate when conditions change. When the AAR is reduced due to traffic management initiatives, it is referred to as the Efficiency AAR. When no traffic management initiatives are in effect it is referred to as the Capacity AAR.
  • ACID. The airline and flight number as identified by TFMS. The airline code typically identifies the operating carrier.
  • Actual (Yes, No). "YES" indicates that the demand for this flight ended within the scope of the report, whereas a "NO" indicates the flight did not have Wheels Off or Wheels On within the scope of this report. "YES" also indicates these flights are the flights used for efficiency computation, whereas "NO" flights will be picked up on a report with a later time frame.
  • Actual Arrivals. The number of flights that arrived on a given date to a selected airport.
  • Actual Departures. The number of flights that departed on a given date from a selected airport.
  • Actual Gate Arrival. The Gate In Time.
  • Actual (Gate Out Departures, Wheels Off Departures, Wheels On Arrivals, and Gate In Arrivals). In the Operational Counts report, the count of Efficiency Departures (Gate Out and Wheels On) and Efficiency Arrivals (Gate In and Wheels On). The term "Actual" in this report, is used to distinguish these counts from "Scheduled" and "Flight Plan" counts. Many, but not all Efficiency Flights have a schedule or flight plan.
  • Actual Time 40 to Wheels On. The amount of time elapsed between the time the aircraft crossed the 40-mile circle and wheels-on (in minutes).
  • Actual Time at 40. The actual time that the aircraft crossed the 40-mile circle.
  • Actual Total. The total number of departures and arrivals on a given date at a selected airport.
  • ADC for 24 Hours Period. The Average Daily Capacity per day as defined by 24 hours. For more information, see the definitions for Average Daily Capacity.
  • ADC for Reportable Hours. The Average Daily Capacity limited to the facility reportable hours. For more information, see the definitions for Average Daily Capacity.
  • Adjusted. A filter option for calculating an adjusted TAER based on the higher of the hourly Arrival Efficiency Counts or Facility Reported Arrivals. Helpful especially for next day reporting where TFMS counts may be artificially low.
  • ADR Plus Capacity AAR. The sum of the ADR and Capacity AAR.
  • ADR. The Airport Departure Rate, or the number of departures an airport can support, per unit of time.
  • Adjusted Arrival Capacity. The AAR adjusted to account for situations in which the actual arrivals or departures exceeded the called rates. See ASPM Efficiency: AAC Distribution Report for more information.
  • Adjusted Departure Capacity. The ADR adjusted to account for situations in which the actual departures or arrivals exceeded the called rates. See ASPM Efficiency: AAC Distribution Report for more information.
  • Airborne Holding Events. The number of flights subjected to airborne holding. Airborne holding is a procedure whereby enroute aircraft are issued a clearance for a predetermined maneuver which keeps aircraft within a specified airspace while awaiting further clearance from ATC. Airborne holding is caused by any number of factors: airport arrival demand exceeds airport arrival capacity, equipment outages, aircraft emergencies, enroute weather, airport gridlock, and sector saturation.
  • Airborne Holding Minutes. The total number of minutes of holding for flights subjected to airborne holding. For more information, see the definition for Airborne Holding Events.
  • Aircraft Category. Categories of aircraft engines. Permissible values are turbine, jet, piston, and helicopter.
  • Aircraft. Four-character code identifying the type of aircraft. Also available as filter option for choosing the aircraft code.
  • Airport. Three- or four-letter code identifying the airport.
  • Airport Adjusted Capacity. The airport hourly capacity (AAR + ADR) adjusted to account for situations in which either or both the actual arrivals and departures exceeded the called rates. See ASPM Efficiency: AAC Distribution Report for more information.
  • Airport Weather. Represents the local weather phenomena at this airport. The source is NOAA, acquired daily. A "+" sign means "Heavy" when used in conjunction with a local weather phenomena. See Local Weather Codes for a listing of the local weather phenomena and their factor weights.
  • Airport Weather Impact. Level of severity of the weather phenomenon affecting the selected airport. Determined by applying factor weights to observed phenomena (none, minor, moderate, severe).
  • Approach Angle. The direction from the arrival airport in degrees of true north.
  • Approach Conditions (All, IMC, VMC). Filter option sorting approach conditions as All, Instrument Meteorological Conditions (IMC), and Visual Meteorological Conditions (VMC).
  • Arrival Airport. Three- or four-letter code identifying the airport of arrival.
  • Arrival Demand Units (Airport Perspective). The number of aircraft that intended to land at a specific airport per 15-minute period. Arrival demand units are reported by quarter hour, and aggregated to the hour. A single flight may have up to four units of demand in one hour. The estimated unimpeded wheels on time is compared to actual wheels on time to determine the number of units of demand for each flight. The estimated unimpeded wheels on time takes into account the aircraft weight and classification, weather conditions (IMC/VMC), runway configuration, and crossing point at 100 miles from the airport. The Start of Demand time may be adjusted for flights with start and end of demand times separated by 5 or fewer minutes, so that there is only one five-minute demand period. In Efficiency Reports, arrivals are aggregated by the end of demand hour (wheels on).
  • Arrival Demand Units (System Perspective). The number of aircraft that intended to land at a specific airport per 15-minute period. Arrival demand units are reported by quarter hour, and aggregated to the hour. The start of demand corresponds to Actual Wheels off plus Estimated Time Enroute. End of demand corresponds to the actual Wheels On time. For flights with missing Actual Wheels Off Time, an estimated value may be derived from the DZ message. If there is an EDCT on a flight, then the Start of Demand is equal to Wheels Off Time plus Estimated Time Enroute minus the delay due to the flight having an EDCT. A single flight produces more than one unit of demand if the difference between the Estimated Wheels On and Actual Wheels On Time spans more than one quarter hour period. The Start of Demand time may be adjusted for flights with start and end of demand times separated by 15 or fewer minutes, so that there is only demand unit. In Efficiency Reports, arrivals are aggregated by the end of demand time (wheels on). Also see SAER_Demand_Computation and SAER for more detail.
  • Arrival Efficiency (System Perspective). The ratio of Arrivals for Efficiency Computation to the lesser of the Efficiency AAR or Arrival Demand Units, expressed as a percentage. Arrival Efficiency is limited to a maximum of 100 percent.
  • Arrival MC. The meteorological conditions at the airport at the time of flight arrival. Possible values are IAC (Instrument Approach Conditions) and VAC (Visual Approach Conditions).
  • Arrival Runway. The runways contained in the arrival runway configuration in effect at the arrival airport.
  • Arrival SAER. The Arrival Efficiency Rate, or the number of arrivals divided by the lesser of the Arrival Demand or the facility-set Arrival Rate, expressed as a percentage. In the SAER For Reportable Hours Report, metric can apply to 24 Hours or Reportable Hours.
  • Arrivals For Efficiency Computation. All observed flight arrivals to the ASPM77 airports handled by controllers. In addition to commercial itinerant operations, also includes general aviation and military flights and local operations. Most VFR traffic is excluded. Arrivals for Efficiency Computation are aggregated based on the end of demand time (wheels on).
  • Arrivals with CountOps. A yes/no flag or count indicating whether the flight record(s) have CountOps data (On and Off times and Runway identifier).
  • Arrivals with EDCT. The number of arrivals with an Expect Departure Clearance Time (EDCT).
  • Arrivals with OOOI. A yes/no flag or count indicating that the flight(s) have Out, Off, On, and In times from ARINC, TFMS, or ASQP.
  • Arrivals. The total number of departures at the selected airport(s). In the SAER For Reportable Hours Report, metric can apply to 24 Hours or Reportable Hours.
  • ASPM Wheels On. The Wheels-On time as reported in ASPM. For flights with OOOI from ARINC, TFMS, or ASQP the Wheels on time is actual. Since October 1, 2012, CountOps also provides actual Wheels On times for most flights without OOOI times from other sources. The ASPM Wheels on time for flights without actual Wheels On times from ARINC, TFMS, ASQP, or CountOps are estimated.
  • Available Scheduling Capacity. The Airport Adjusted Capacity minus the actual number of scheduled and unscheduled arrivals and departures. This measure is intended to provide an indication of airport congestion. Higher values indicate excess capacity; lower values indicate more congestion; negative values indicate that actual operations exceeded the stated capacity.
  • Available Scheduling Capacity Arrivals. The Adjusted Arrival Capacity minus the Actual number of Scheduled and Unscheduled Arrivals.
  • Available Scheduling Capacity Departures. The Adjusted Departure Capacity minus the actual number of Scheduled and Unscheduled Departures.
  • Average Actual 100-to-40 Time (minutes). In the Runway Configuration Report, the average flight time for arriving flights from 100-miles to 40-miles from the airport for the specified runway configurations.
  • Average Actual 40-to-On Time (minutes). In the Runway Configuration Report, the average flight time for arriving flights from 40-miles to wheels on for the specified runway configurations in effect at the time.
  • Average Daily Capacity (ADC). The Average Daily Capacity, calculated as the sum of the Airport Departure Rates (ADR) and the Capacity Airport Arrival Rates (AAR) divided by the number of days in the period under consideration.
  • Average Excess Minutes 100 To 40 Miles. The average difference between the actual and unimpeded time from 100 to 40 miles from the arrival airport. The unimpeded time is the average time in the previous 12-months, for the 20% of flights with the shortest travel distance, for a given 40-mile crossing point, equipment type, weight class, meteorological conditions, and runway configuration.
  • Average Excess Minutes 40 To Wheels On. The average difference between the actual and unimpeded time from 40 miles to wheels on. The unimpeded time is the average time in the previous 12-months for the 20% of flights with the shortest travel distance from 100 to 40, for a given 40-mile crossing point, equipment type, weight class, meteorological conditions, and runway configuration.
  • Average Hourly Go Arounds. In the Runway Configuration Report, the average number of Go-Arounds per hour for the specified runway configuration(s).
  • Average Hourly AAR+ADR. In the Runway Configuration Report, the average AAR + ADR in effect for the specified runway configuration(s).
  • Average Hourly Throughput. In the Runway Configuration Report, the average hourly throughput for the specified runway configuration(s).
  • Average Minutes (40 Miles to On). The average time from 40 miles to wheels-on for the shortest (distance) 20% of flights from the 100-mile crossing point to the 40-mile crossing point.
  • Average MPH (100 to 40). The average speed for the shortest (distance) 20% of flights used for TAER means calculations.
  • Average Taxi In Time. The average difference between Actual Gate In time and Actual Wheels On time, in minutes. Taxi in time is observed for flights for which OOOI data are available, otherwise, it is estimated.*Wind Direction = Wind Angle
  • Average Taxi Out Time. The average difference between Actual Gate Out time and Actual Wheels Off time, in minutes. Taxi out time is observed for flights for which OOOI data are available, otherwise, it is estimated.
  • Average Unscheduled Arrivals The number of Unscheduled Arrivals divided by the number of time periods. Unscheduled Arrivals are calculated as Efficiency Arrivals plus ½ VFR operations from OPSNET, minus actual scheduled arrivals (scheduled arrivals minus scheduled arrival cancellations).
  • Average Unscheduled Departures The number of Unscheduled Departures divided by the number of time periods. Unscheduled Departures are calculated as Efficiency Departures plus ½ VFR operations from OPSNET, minus actual scheduled departures (scheduled departures minus cancellations for scheduled departures).
  • AZ Time. The time the aircraft lands on the runway. This field is provided by ASQP or ARINC data, otherwise, it is estimated from the AZ (arrival) message.
  • Base on Departures or Arrivals. (System Perspective). Filter option allowing the user to base the report on Departures only or Arrivals only.
  • Cancellations (Departure, Arrival). The super-set of cancelled departure and arrivals as determined by the combination of scheduled flights not flown and flight plans cancelled that were not re-filed for ASPM carriers and all other carriers reporting schedule data; and ASQP flight cancellations (received approximately six weeks after the end of each month).
  • Capacity AAR. The Capacity Airport Arrival Rate. The number of arrivals an airport can support per unit of time when no traffic management initiatives are in effect. For more information, see the definition for Efficiency AAR.
  • Carrier. 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.
  • Ceiling (100) Feet. The sky conditions within 100 feet AGL of the lowest level of clouds that is reported as "broken", "overcast", or "obscured".
  • Completion Rate. The percentage of scheduled and/or planned air carrier arrivals that were not cancelled. Calculated as Metric Arrivals/(Metric Arrivals + Cancelled Arrivals). Cancelled Arrivals are determined next day using air carrier flight plan cancellation messages and scheduled flights not flown. ASQP cancellation data are used when available.
  • CountOps Arrival ACID. The airline and flight number.
  • CountOps Arrival Runway End. The runway end as identified by the radar tracks for arriving flights.
  • CountOps Available. This variable is marked Y (YES) or N (NO). It indicates whether actual CountOps counts of air traffic activity was used to construct the ASPM record.
  • CountOps IFR (Departures, Arrivals, Total). Count of operations under Instrument Flight Rules (IFR) from CountOps, an automated system for developing official counts of facility operations equal to OPSNET operations.
  • CountOps Itinerant IFR Arrivals. Count of IFR itinerant arrivals from CountOps, an automated system for developing official counts of facility operations equal to OPSNET operations.
  • CountOps VFR (Departures, Arrivals, Total). Count of operations under Visual Flight Rules (VFR) from CountOps, an automated system for developing official counts of facility operations equal to OPSNET operations.
  • CountOps Wheels On. The CountOps Wheels On time is the runway threshold crossing time for arrivals provided CountOps. CountOps is a database of radar track points for flights within 40 miles of an airport. CountOps is a subset of Offload.
  • Current Period Qtrs. The number of quarter-hour demand units for the selected flights. Some flights may not land in the current report time frame and therefore carry over to other reports.
  • Demand Hour From 00–23 To 00–23. Filter option allowing the user to limit the report to a subset of daily demand hours.
  • Demand Quarters. The number of aircraft that intended to land at a specific airport per 15-minute period.
  • Departure Airport. Three- or four-letter code identifying the airport of departure.
  • Departure Demand Units. The number of aircraft that are ready to depart from the airport, used in calculation of the SAER. Flights that depart within 15 minutes of the expected departure time receive one unit of demand within that 15-minute period. Flights that leave more than 15 minutes late accumulate additional units of demand in subsequent 15-minute periods. Therefore, departure demand for a particular flight can occur in several 15-minute time periods. The expected departure time (or Start of Demand) is calculated as the Gate Out Time + Unimpeded Taxi-Out Time. The actual departure time (or End of Demand) is the Wheels Off Time. When an EDCT Delay is present, the duration of EDCT Delay is excluded from departure demand calculations and added to the Arrival side. This adjustment is made because, in the case of Ground Delay Programs with EDCTs, excess departure demand may be caused by capacity restrictions at the arrival airport. Also see SAER_Demand_Computation and SAER for more detail.
  • Departure Efficiency. The ratio of Departures for Efficiency Computation to the lower of the ADR or departure demand for a given runway configuration, meteorological conditions, and time period, expressed as a percentage. Departure Efficiency rate is limited to a maximum of 100 percent.
  • Departure SAER. The Departure Efficiency Rate, or the percentage of time departures that are greater than or equal to departure demand or the facility-set departure rate. The percentage is determined by dividing actual departures by the lesser of the departure demand or the departure rate. In the SAER For Reportable Hours Report, metric can apply to 24 Hours or Reportable Hours.
  • Departures For Efficiency Computation. All observed flight departures from the ASPM77 airports. In addition to commercial itinerant operations, also includes general aviation and military flights and local operations. Includes some partial records with incomplete data. Intended to provide a complete representation of departures from the ASPM77 airports.
  • Departures. Total number of departures at selected airport. In the SAER For Reportable Hours Report, metric can apply to 24 Hours or Reportable Hours.
  • Distance 100-40. The straight line distance in nautical miles from the 100-mile crossing point to the 40-mile crossing point for airport arrivals. The actual distance flown may exceed this distance due to vectoring or holding.
  • Domestic Carrier (All, Yes, No). Indicates whether or not the carrier operates within the United States.
  • Diversions. Counts of flights that were diverted from their originally intended arrival airport as detected by an algorithm written by Mitre.
  • EDCT Delay. EDCT (Expect Departure Clearance Time) Delay is the difference of one minute or more, between the EDCT Wheels Off time and the planned airport departure time. EDCTs are generated by Ground Stops or Ground Delay Programs initiated by the arrival airport, instructing aircraft at the departure airport to remain on the ground (no wheels off) until the EDCT Wheels Off time. EDCT delays are assigned to the arrival airport. In SAER calculations, the Start of Demand for arrivals is adjusted by the amount of EDCT delay experienced at the departure airport. The EDCT Wheels Off time is displayed on the Flight-per-Page report in the Individual Flights module.
  • Effective Scheduled Arrivals. The number of Scheduled Arrivals - Scheduled Flights Not Flown Arrivals.
  • Effective Scheduled Departures. The number of Scheduled Departures - Scheduled Flights Not Flown Departures.
  • Efficiency (Departures, Arrivals, Total). Arrivals and departures to the ASPM 77 airports handled by controllers. In addition to commercial itinerant operations, also includes general aviation and military flights and local operations. Most VFR traffic excluded. Intended to provide a complete representation of arrivals and departures handled by controllers for the ASPM 77 airports.
  • Efficiency AAR. Efficiency Airport Arrival Rate. The number of arrivals an airport under current conditions, which is the lesser of the Capacity AAR or a reduced rate when traffic management initiatives such as Ground Delay Programs are in effect. For more information, see definition for Capacity AAR.
  • Efficiency Operations for 24 Hour Period. The number of Efficiency Operations per day as defined by 24 hours.
  • Efficiency Operations for Reportable Hours. The number of Efficiency Operations that occur during reportable hours.
  • End of Demand Time. The Wheels On time. This field is observed directly in ASQP or ARINC data, otherwise, it is estimated from OOOI. Wheels On Time may come after or before the AZ time by an amount of time defined to be Gap AZ time. ASQP Wheels On Time is accepted as the correct Wheels On Time.
  • End Qtr (hh-q). The hour and quarter hour the SAER or TAER demand ends.
  • Ending Hour. The last reportable hour of the day.
  • Estimated Time 40 to Wheels On. The unimpeded time for the aircraft to travel from the 40-mile circle to wheels on, based on the average time from the 40 mile crossing point to wheels on in the previous 12-months for the 20% of flights with the shortest travel distance, for a given 40 mile crossing point, runway configuration, equipment type, weight class, and meteorological conditions.
  • Estimated Time at 40. The time at the 100-mile circle plus the estimated time to fly from the 100-mile crossing to the approach point closest to the where the aircraft crossed the 40-mile circle. The estimated time is based on the average speed for the 20% fastest aircraft for a given 40-mile crossing point, runway configuration, equipment type, weight class, and meteorological conditions.
  • ETA Calculation (ETA Calc). The count of the number of times ASPM can successfully compute the estimated time of arrival (ETA) for a given flight for use in the TAER calculation. A flight record with incomplete circle crossing times cannot be used for calculating the TAER.
  • ETE. The Estimated Time Enroute, which is the Flight Plan Airborne Time, in minutes.
  • ETMS Available. This variable 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), DZ and AZ data, and OOOI times for certain airlines (starting FY15). If an ETMS record was not used, then flight plan times and DZ and AZ times are estimated.
  • Facility Reported Arrivals. The number of arrivals reported by the facilities to the Operational Information System (OIS). Hours required: 6:59 to 21:59.
  • Facility. Three-letter code identifying the facility.
  • Flight Number. The number identifying the flight as assigned by the air carrier. Permissible values: 1–9999.
  • Flight Plan Gate Arrival. The Gate In Time according to the Flight Plan, 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 Departures and Gate Arrivals). In the Operational Counts report, the number of Efficiency departures and arrivals for which flight plan data are available.
  • Flight Type (All, Domestic, International). Filter option indicating flight direction. Permitted variables are: All, Domestic (both arrival and departure are in the US), and International (arrival and/or departure are in a foreign country).
  • Flights with TAER from 100 Miles (Number and %). The number of flights that were at least 100-miles long with all the data required for calculating a TAER without using defaults.
  • Flights with TAER from 40 Miles (Number and %). The number of flights that were between 40 and 100-miles long with all the data required for calculating a TAER from the 40-mile crossing point without using defaults.
  • Flights Using Default Means (Number and %). In the TAER Summary Counts Report, the number of flights for which default values in the means table are applied, based on all flights crossing the observed 40-mile approach angle. Default means are applied when there were fewer than ten similar flights observed in the past year for the five factors used for calculating means.
  • Flights Using SAER Demand (Number and %). In the TAER Summary Counts Report, the number of flights for which the SAER demand is used in TAER calculations. SAER demand is used when a circle file is not available on the flight record.
  • Gate Arrivals (Actual). The number of actual gate arrivals.
  • Gate Arrivals (Flight Plan). The number of gate arrivals according to the Flight Plan.
  • Gate Arrivals (Scheduled). The number of gate arrivals according to the Schedule.
  • GMT Hour. The hour of the day in Greenwich Mean Time, ranging from 0-23.
  • Go Around. An aborted landing of an aircraft on final approach. The reported numbers do NOT include Military, HELO, "Touch and Go", unknown, or untagged operations. For more information about Go Arounds, see Go Around: Defined Business Rules. In the ATCSCC Metrics Report'NR' indicates that Go Arounds are not reported for the listed facility.
  • Ground Stop Events. The number of delayed operations for aircraft included in a ground stop and delayed for 15 or more consecutive minutes.
  • Ground Stop Minutes. The total minutes of delay for aircraft included in a ground stop and delayed for 15 or more consecutive minutes.
  • Local Hour. The hour of the day in local time, ranging from 0-23. The time range is inclusive of the entire hours, i.e., the 21 hour includes time through 21:59. Local hour used in efficiency calculations is based on Wheels Off or Wheels On time.
  • Local Time. The hour of the day in local time, ranging from 0-23. The time range is inclusive of the entire hours, i.e., the 21 hour includes time through 21:59. Local hour used in efficiency calculations is based on Wheels Off or Wheels On time.
  • Means Default Flag. "Yes" indicates that a default average speed from 100 to 40 miles and time from 40 miles to wheels on were applied to the flight for the purpose of calculating demand units. Default means are used when there were fewer than 10 instances of the observed five-factor combination (IMC/VMC, physical class, weight class, approach angle, and runway configuration) for flights crossing both the 100-mile and 40-mile circle in the previous 12 months.
  • Means For. The time period that the TAER means apply to. Means are recalculated monthly based on the previous 12-months of data.
  • Metric (Departures, Arrivals, Total). The count of operations for metric computation. Flight operations used for calculating metrics in ASPM. Only flight records that meet the following criteria are included: itinerant flights to or from one of the ASPM 77 airports or operated by one of the ASPM Carriers with actual arrival and departure, and flight plan times that are reported or can be estimated from the other flight record data. General aviation and military flights are excluded.
  • Minimum Demand Quarters. Filter option allowing users to limit the report to flights that produce demand in a minimum number of demand quarters.
  • Min Miles. A measure of the extent of En Route and Arrival Miles-In-Trail restrictions by arrival airport. Departure MITs are excluded. Minute-miles are calculated by multiplying the severity of the MIT restriction (in miles) by the duration of the MIT restriction (in minutes). For example, a 20 miles-in-trail restriction lasting 30 minutes = 600 minute/miles. This measure is contained in the ATO Efficiency Report, and the ATO Efficiency Summary Report.
  • n/a. A value of "n/a" for any of the fields in the Efficiency Detail report indicates that the required data for that field was not available for that particular flight. For example, a value of "n/a" for Time 100-40 indicates the flight did not cross the 100-mile circle (or ASPM did not receive a circle record for that flight), so the elapsed time could not be calculated. If a 100-mile circle file is not available, the 40-mile crossing time is used to calculate TAER demand. If neither a 100-mile or 40-mile circle file is available, the wheels-off time plus the Estimated Time Enroute (also used as the SAER start of demand) is used as the TAER start of demand.
  • Number of Hours. In the Runway Configuration Report, the number of hours in which the specified runway configurations were in use.
  • OOOI Available. 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.
  • OOOI Source. Indicates the source of Gate Out, Wheels Off, Wheels On, and Gate In times. The possible values are "None" meaning that no OOOI is available for that flight, OAG, TFMS, or ASQP. ASQP OOOI is used where available, followed by OAG OOOI or TFMS OOOI in priority order.
  • OPSNET Local Departure Delays. The sum of Departure Delays attributed to conditions at the departure airport and Local TMI From Delays resulting from traffic management initiatives requested by a TRACON or Center.
  • OPSNET Delays. The number of delayed operations for the selected airport(s), as reported by OPSNET.
  • OPSNET Operations. The number of total operations worked by the selected airport(s), as reported by OPSNET.
  • Percent ADC for Reportable Hours of 24 Hour Period. The percent of Average Daily Capacity that occurs during reportable hours.
  • Percent Efficiency Operations for Reportable Hours of 24 Hour Period. The percentage of efficiency operations that occur during reportable hours.
  • Percent of Hours. In the Runway Configuration Report, the percent of hours in which the specified runway configurations are in use.
  • Physical Class. Categories of aircraft engines. Permissible values are turbine, jet, piston, and helicopter.
  • Runway. The runway configuration (Arrivals|Departures) in effect at that particular airport and time.
  • SAER. The System Airport Efficiency Rate (SAER) is the weighted average (by demand) of the Departure Efficiency rate and Arrival Efficiency rate for the same airport by quarter hour. As a filter option, it produces a report based on the System (SAER) perspective.
  • Scheduled Arrivals. Number of arrivals listed in a published schedule.
  • Scheduled Departures. Number of departures listed in a published schedule.
  • Scheduled Flights Not Flown Arrivals. Number of Scheduled Flights that did not fly, resulting in a cancelled arrival.
  • Scheduled Flights Not Flown Departures. Number of Scheduled Flights that did not fly, resulting in a cancelled departure.
  • Scheduled Gate Arrival. The Gate In Time according to Schedule, otherwise calculated from the ETMS Flight Plan using the following formula: Flight Plan Gate Out time plus Unimpeded Taxi Out, plus Flight Plan Expected Time Enroute, plus Unimpeded Taxi In.
  • Scheduled (Gate Departures and Gate Arrivals). In the Operational Counts report, the number of Efficiency departures and arrivals for which schedule data are available.
  • Seats From… To. Filter option to limit the report to flights within a certain seat range in number of seats.
  • Selling Carrier. An airline that sold tickets for a flight. The flight may have been operated by a different airline. The operator airline is identified by the ACID.
  • Sort by Start of Demand, End of Demand, Start of Demand Time, or Carrier/Flight Number. Filter option allowing user to sort the flights on the report by Start of Demand Time, End of Demand Time, or Carrier and Flight Number.
  • Speed 100-40. The average aircraft speed between the 100- and 40-mile crossing points.
  • Start of Demand Date. The local date when demand started.
  • Start of Demand End Of Demand Diff. End of Demand time minus Start of Demand Time, in minutes.
  • Start of Demand Time. The unadjusted start of demand if no adjustment is warranted. If an adjustment is applied to reduce the number of demand quarters as indicated with a "YES" in the Starting Bin Adjusted column, then the time is shifted forward to the start of the next quarter. SAER uses 15-minute bins for determining adjustments, whereas TAER uses 5-minute bins. In addition, if the actual wheels on time is before the expected wheels on time as displayed in the Start of Demand column, the Start of Demand Time is set to equal the actual wheels on time.
  • Start of Demand. The expected wheels on time as calculated from the 100- and 40-mile crossing times and TAER means tables. This value can differ from the Start of Demand Time if adjustments are applied. See Start of Demand Time for more detail.
  • Start Qtr (hh-q). The hour and quarter hour the SAER or TAER demand began.
  • Starting Bin Adjusted. A "YES" indicates that the start of demand was adjusted forward to the beginning of the next quarter hour. For the TAER this adjustment is made when the start and end of demand are in different quarters, and the duration of demand (difference between them) is 5 minutes or less. The duration for the binning adjustment is 15 minutes for the SAER. The impact of the adjustment is to give the flight one unit of demand instead of two.
  • Starting Hour. The first reportable hour of the day.
  • Status Code. The code indicating whether the record has a matching circle file indicating crossing times and locations at 100 and 40 miles from the airport. "0" indicates that the flight has a circle file. "1" indicates that no circle file was located. "2", "4", or "5" indicate that the SAER demand was used because the times did not make sense.
  • TAER. The Terminal Arrival Efficiency Rate (TAER) is calculated by dividing the Arrivals For Efficiency Computation by the lesser of the Arrival Demand or the Efficiency Airport Arrival Rate. The TAER is reported for a time period of an hour or more. For reports covering a period greater than an hour, the reported TAER is a weighted average of every hour in the period based on the number of arrivals. As a filter option, it produces a report based on the Terminal (TAER) perspective.
  • TAER for Reportable Hours. The TAER limited to reportable hours.
  • TAER Mod+Sev Wx. The TAER value calculated for the hours in which the weather was classified as moderate or severe based on the ASPM weather factors methodology. If there was no moderate or severe weather during the timeframe specified, the TAER value is blank. If there were no arrivals during the moderate or severe weather periods, the TAER value is reported as zero. The Weather Factors methodology categorizes and reports on the severity of a combination of weather factors (wind speed, ceiling, visibility, nearby thunderstorms, en route thunderstorms, and airport weather such as rain and snow) in terms of their impact on flight delays. For more information on Weather Factors, see the ASPM Weather Factors Manual.
  • Tail Number. Aircraft identification number located on the tail of the aircraft (for most GA traffic) or carrier code plus flight number.
  • Taxibacks. The number of flights that pull away from the gate then taxi back to the gate prior to departure. Taxiback flights may depart later or ultimately be cancelled. In the ATCSCC Metrics report, 'NR' indicates that Taxibacks are not reported for the facility listed.
  • Taxi In Time. The Taxi In Time in minutes is either observed or estimated by calendar year for each carrier and airport reportable ASQP and ARINC data.
  • Temp (F). Average temperature in degrees Fahrenheit.
  • TFMS (Departures, Arrivals, Total). The count of operations with DZ (departure) or AZ (arrival) messages as reported by TFMS at the selected facility. Additional, less complete TFMS records (no AZ or DZ present) may have also been used to create ASPM records. TFMS reports predominantly IFR operations, but also includes some operations reported as VFR in CountOps. Due to limited radar coverage and incomplete messaging, TFMS may exclude certain flights that do not enter the en route airspace and other low-altitude flights.
  • Time 100-40. The amount of time elapsed between the 100-mile crossing and the 40-mile crossing (in minutes).
  • Time 40 to Wheels On Difference. The difference between the estimated and actual time for an aircraft to travel from the 40-mile circle crossing to wheels on (in minutes).
  • Time at 40 Difference (Min). The difference between the estimated time at 40 and the actual time at 40. "n/a" indicates the flight did not cross the 100-mile circle (or data were not available), so the estimated time at 40 could not be calculated.
  • Total EDCT For Arrivals Where EDCT>0. Total minutes of EDCT delay for aircraft with an EDCT.
  • Total Demand Units. The sum of Departure Demand and Arrival Demand.
  • Total Flights. On the TAER Means report, the number of flights observed in the previous twelve months for each combination of airport, arrival runway configuration, approach angle, physical class, weight class, and arrival meteorological conditions. All flights for the previous 12 months that cross both the 100 mile circle and 40 mile circle are used for calculating the mean speed from 100 to 40 and mean time from 40 to wheels on. To calculate the mean speed from 100 to 40, flights for each five-factor combination are ranked by actual distance flown 100 to 40 for each cell, and the distance and actual crossing times are used to compute the mean speed for the 20% most direct (shortest distance) flights. Independently, we rank the actual distance flown from 40 to wheels on for each cell, and calculate the mean time for 20% most direct (shortest distance) flights. These values are used for calculating the estimated unimpeded time from the 100 mile crossing point to wheels on. The means are applied to the following month and forward until the next month of ASQP data are received.
  • Total Number of Qtrs. The sum of the demand quarter units.
  • Total SAER. The total weighted average (by demand) of the Arrival Efficiency Rate and Departure Efficiency Rate. In the SAER For Reportable Hours Report, metric can apply to 24 Hours or Reportable Hours.
  • Totals For Efficiency Computation. The sum of Departures and Arrivals for Efficiency Computation.
  • Use Adjusted Values. A filter option for calculating an adjusted TAER based on the higher of the hourly Arrivals for Efficiency Computation or Facility Reported Arrivals.
  • Unadjusted Start of Demand Time (System Perspective). The expected wheels on time, as calculated by the Gate Out time, plus Unimpeded Taxi Out time, plus the Estimated Time Enroute (ETE).
  • Visibility (Statute Miles). Meteorological visibility range, expressed in statute miles.
  • Weather. Meteorological conditions classified as Instrument Meteorological Conditions (IMC) or Visual Meteorological Conditions (VMC).
  • Weight Class. The physical weight categories of the aircraft. These are assigned by APO130 based on the ETMS observed aircraft codes. See Weight Class.
  • Wheels Off Departures (Actual). The number of actual wheels-off departures.
  • Wheels Off Time. The time the aircraft takes off. This field is obtained from ASQP, ARINC, or TFMS OOOI data, or the CountOps Runway Threshold Crossing Time, otherwise it is estimated from the DZ message.
  • Wheels On Arrivals (Actual). The number of actual wheels-on arrivals.
  • Wind Angle/Direction. The direction from which the wind is blowing relative to true north measured in degrees. A value of 'VR' or 'VRB' indicates variable wind angle. A value of 0 indicates no wind.
  • Wind Speed (Knots). Wind speed at the selected airport, expressed in knots.