ASPM City Pair Enroute: Definitions of Variables

The following definitions define the fields in the ASPM reports of City Pair Enroute:

• 10th (percentile). In the Unimpeded Report, the 10th percentile of the enroute time and miles flown and average speed distribution.
• 1st (percentile). In the Unimpeded Report, the 1st percentile of the enroute time and miles flown and average speed distribution.
• 25th (percentile).In the Unimpeded Report, the 25th percentile of the enroute time and miles flown and average speed distribution.
• 5th (percentile). In the Unimpeded Report, the 5th percentile of the enroute time and miles flown and average speed distribution.
• 75th (percentile).In the Unimpeded Report, the 75th percentile of the enroute time and miles flown and average speed distribution.
• 90th (percentile). In the Unimpeded Report, the 90th percentile of the enroute time and miles flown and average speed distribution.
• 95th (percentile). In the Unimpeded Report, the 95th percentile of the enroute time and miles flown and average speed distribution.
• Actual Arrival Date. Local date of arrival. MM/DD/YYYY.
• Arrival Airport. Three- or four-character code identifying the arrival airport.
• Average (Time Flown Minus Unimpeded Time). The sum of the time flown from the 100-nautical mile GCR boundary of the departing airport to 100-nautical mile GCR boundary of the arriving airport less the unimpeded enroute time (10th percentile) calculated by the Excess Time Method divided by the number of flights. Negative value is allowed.
• Average Excess Miles Flown. The Average Excess Miles Flown is the average difference between the actual miles flown enroute minus the GCR distance enroute.
• Average Excess Time Flown. The Average Excess Time Flown is the sum of time flown from the 100-nautical mile from the departing airport to 100-nautical mile from the arrival airport less the unimpeded enroute time (10th percentile) calculated by dividing the Excess Time Method by the number of flights. Negative excess times are set to zero.
• Average Miles Flown. The average of the enroute miles flown (100-nautical miles boundary to 100-nautical miles boundary).
• Average Speed Deficit. The average of the unimpeded speed (90th percentile) minus the observed speed.
• Average Speed. The average of the nautical miles flown enroute divided by the flight time enroute. Enroute Data: The average speed of the aircraft crossing the 100-nautical miles GCR boundary from the departing airport to crossing the 100-nautical mile GCR boundary from the arrival airport. Unimpeded speed is the 90th percentile.
• Average Time Flown. The average of the enroute elapsed flight time from 100-mile to 100-mile boundaries. Measured per GCR path not actual flight path.
• Carrier Code. The code extracted from the ACID (TFMS) when the first three letters of the ACID are characters and are followed by one or more digits. Flights that do not meet this criterion are usually denoted by Tail Numbers. Flights without Carrier Code may also represent general aviation or military flights. For these flights, the Carrier Code is set to N/A. Flight Numbers are also extracted from ASQP/ARINC data, which may contain a two-character code, which is converted to three. The code "ALL" refers to all the carriers, including ASQP carriers. A carrier code of "OTH" represents all the other carriers except the ASQP carriers, FDX, UPS, COM, and ACA.
• City Pair Data (Airport to Airport). The Wheels Off to Wheels On data.
• Crossing Time. The Universal Time Coordinate (UTC) or (GMT) time when a flight leave a segment. Segments are identified as the following: 40 Mile from Departure Airport, 40 Mile to 100 Mile, 100 Mile to 200 Mile, 200 Mile to Midpoint, Midpoint to 200 Mile, 200 Mile to 100 Mile, 100 Mile to 40 Mile, and 40 Mile to Arrival Airport.
• Departure Airport. Three- or four-character code identifying the departure airport.
• Distance Flown. The nautical miles as flown between defined segment boundaries.
• Distance from GCR. The nautical miles from the flight path to the Great Circle Route (GCR) path when the flight path exits a segment. When the GCR is left (port) of the flight path the value is considered to be positive and when the GCR to the right (starboard) of the flight path the value is negative.
• Enroute Data (100 mile to 100 mile). Data on enroute performance 100-nautical mile boundary from departure to 100-nautical mile boundary from arrival.
• Enroute GCR (100 to 100). Enroute GCR distance (100 mile to 100 mile) for the selected the city pairs.
• Enroute Miles Flown. Nautical miles flown from the 100-nautical mile circle boundary to the arriving 100-nautical mile circle boundary.
• Enroute Time Flown. The time flown from the 100-nautical mile circle of the departing airport to 100-nautical mile circle of the arriving airport.
• Enroute Time Minus Unimpeded Time. The time flown from the 100-nautical mile circle of the departing airport to 100-nautical mile circle of the arriving airport less the unimpeded time (enroute time flown 10th percentile). Negative value is allowed.
• ETMS Equipment Code. ETMS/TFMS Aircraft Type designator. This is usually a three- or four-character field extracted from a TFMS flight plan or from an available ASQP record.
• Excess Miles Flown. Actual nautical miles have flown 100-nautical miles from departure airport to 100-nautical miles from arrival airport minus GCR distance.
• Excess Time Flown. The actual time flown from the 100-nautical mile circle of the departing airport to 100-nautical mile circle of the arriving airport minus the unimpeded time (enroute time flown 10th percentile). Excess time is either 0 or positive.
• Flight Index. One component of the ETMS primary key provided by the NAS Data Warehouse.
• Flight Level. The aircraft altitude in hundreds of feet when exiting the defined segment.
• Flight Number. The number identifying the flight as assigned by the air carrier. Permissible values: 1–9999.
• Flights for Enroute Computation. The flights selected by the user that meet the Enroute Criteria.
• GCR Distance. Enroute Data: The Great Circle Route (GCR) distance from the departing 100-nautical mile boundary to the arrival 100-nautical mile boundary. Also defined to be the city pair GCR distance less 200-nautical miles. Enroute boundary is defined to be an imaginary circle around each airport. City Pair Data: The imaginary circle on the earth surface whose plane passes through the center of the earth and divides the earth into 2 equal parts. The GCR distance is the shortest route of travel.
• Latitude. The aircraft latitude when exiting the defined segment.
• Longitude. The aircraft longitude when exiting the defined segment.
• Mean. In the Unimpeded Report, the mean of the enroute time flown distribution.
• Median. In the Unimpeded Report, the median of the enroute time flown distribution.
• Miles Flown. Number of miles flown based on city pair great circle route.
• Miles Ratio. The nautical miles flown for the segment divided by the GCR distance.
• Physical Class. Categories of aircraft engines. Permissible values: Permissible values: T=Turbine, J=Jet, P=Piston, H=Helicopter, –=Unknown, blank=Missing.
• Ratio Average Speed and Unimpeded Speed. The average of the actual speed flown enroute divided by unimpeded speed (90th percentile calculated by the Excess Time Method).
• Ratio Average Speed and Unimpeded Speed. The average of the actual speed flown enroute divided by unimpeded speed (90th percentile calculated by the Excess Time Method).
• Ratio Miles Flown and GCR Distance. Actual nautical miles flown enroute divided by GCR distance enroute.
• Ratio Time Flown and Unimpeded Time. Actual time flown enroute divided by unimpeded time enroute (enroute time flown 10th percentile calculated by the Excess Time Method).
• Ratio Time Flown and Unimpeded Time. Actual time flown enroute divided by unimpeded time enroute (enroute time flown 10th percentile calculated by the Excess Time Method).
• Standard Deviation. In the Unimpeded Report, the standard deviation of the enroute time flown distribution.
• Sum degrees turn clockwise. The sum of clockwise turns in degrees for an aircraft within a flight segment (not available before 40-mile boundary crossing from Departure Airport).
• Sum degrees turn counter clockwise. The sum of counter clockwise turns in degrees for an aircraft within a flight segment (not available before 40-mile boundary crossing from Departure Airport)
• Time Flown. Amount of time flown, expressed in hours and minutes based on the DZ and AZ times.
• Unimpeded Speed. The Enroute Unimpeded Speed is calculated for the months selected and flights that meet the enroute criteria. It is the 90th percentile value of the average speed distribution from the 100-nautical mile departing airport boundary to 100-nautical mile arrival airport boundary.
• Unimpeded Time. Tenth percentile value of the enroute time flown distribution, 100-nautical mile from departing airport boundary to 100-nautical mile arrival airport, computed based on the user selected base months for the a city pair.
• 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.