IAD
WASHINGTON DULLES INTERNATIONAL AIRPORT
Airport capacity profile estimates were created using a standard set of performance characteristics and do not take into account non-runway constraints,
unless otherwise noted. The capacity estimates developed for this report are not intended to replace the results of any detailed analysis that would
precede an environmental, investment, or policy decision.
Th
e list of Future Improvements and their expected effects on capacity does not imply FAA commitment to, or approval of, any item on the list.
IAD WASHINGTON DULLES INTERNATIONAL AIRPORT
DEFINITION
The capacity profile shows the hourly throughput that an airport is able to sustain during
p
eriods of high demand, represented as the range between the model-estimated capacity
and the ATC facility reported rate (called rate). Each weather condition has a unique
capacity rate range. IAD tends to operate in an arrival or departure priority mode, as
opposed to a balanced operation. An arrival or departure priority operation is only feasible
when the airport’s flight schedule is unbalanced for sustained periods of time.
For each weather scenario, capacity estimates are based on information provided by ATC,
inc
luding reported arrival and departure rates.
R
ECENT CAPACITY IMPROVEMENTS AT IAD
Time-B
ased Flow Management (TBFM) helps to improve the flow of arrivals to the runways.
Arrival-D
eparture Window (ADW) helps to minimize the long-term risk associated with
arrival and departure operations on intersecting and converging runways (e.g., landing
Runway 19R while Departing Runway 30). A range window prior to the arrival runway
threshold is depicted on the controller’s radar monitor. The departing flight cannot be
released if the arrival is within that window, minimizing the risk of separation loss with the
departing aircraft in the event the arrival executes a missed approach.
F
UTURE IMPROVEMENTS AT IAD
Improved Parallel Runway Operations: C
enterline spacing of Runway 1L/19R allows for
Triple Simultaneous Instrument Approaches, however this procedure has not been
implemented yet at IAD and requires the installation of upgraded surveillance equipment.
Such approaches would be implemented until required by traffic levels.
Improved R
unway Delivery Accuracy: The combined effects of several new capabilities,
including ADS-B Out, CDTI, and TBM in the terminal area, will improve the ability of
controllers to deliver aircraft to the runway with the desired separation from the preceding
aircraft. This will reduce the average spacing between arrivals and boost arrival capacity.
Wake R
ecategorization Phase 1 assigns aircraft to new wake turbulence classifications
based on their wake turbulence characteristics, such as wake generation, wake decay, and
encounter effects. This results in closer longitudinal separation for certain aircraft types
without sacrificing safety.
D
ATA SOURCES
Actual hourly IAD operations, weather and configuration data were obtained from the FAA
A
SPM database, and represent operational hours from 7am to 11pm local time for all of
Fiscal Years 2012 through 2014. Actual configuration usage is determined by multiple
operational factors, including weather conditions.
Facility reported rates were provided by ATC personnel at IAD.
Model-e
stimated rates are derived from operational information provided by ATC.
ANNUAL WEATHER AT IAD:
VISUAL CONDITIONS:
Ceiling and visibility allow for visual approaches: at
least 3000 feet ceiling and 7 miles visibility
MARGINAL CONDITIONS:
Ceiling and visibility below visual approach minima
but better than Instrument conditions
I
NSTRUMENT CONDITIONS:
Ceiling and visibility below 1000 feet ceiling or 3
miles visibility
VISUAL – SOUTH FLOW
IAD SCENARIO:
INDEPENDENT APPROACHES, VISUAL SEPARATION
Type Operations Arrival Runways Departure Runways
Hourly Rate
ATC Facility
Reported
Model-
Estimated
CURRENT
O
PERATIONS
ARRIVAL PRIORITY
19C, 19L, 19R 30 156 162
DEPARTURE PRIORITY
19C, 19L, 19R 19L, 30 157 157
F
UTURE IMPROVEMENTS 19C, 19L, 19R 19L, 30 N/A 200
VISUAL WEATHER CONDITIONS
Future improvements: Improved Runway Delivery Accuracy,
Wake Recategorization Phase 1.
The capacity rate range for South Flow operations in Visual
conditions is 156-162 operations per hour in arrival priority
and 157 in departure priority.
The airport operates in the arrival priority configuration
approximately 24% of the time in Visual weather conditions
(totaling 20% annually).
The airport operates in the departure priority configuration
approximately 8% of the time in Visual weather
conditions(totaling 6% annually).
When in departure priority, IAD uses 19L as an overflow arrival
runway. It is assumed that IAD will use all three arrival
runways equally in the future.
Radar separation is used at the Outer Marker and no visual
spacing is allowed behind Heavies or B757s.
The airport has an ADW in place for arrivals to 19R and
departures from 30.
VISUAL – NORTH FLOW
IAD SCENARIO:
INDEPENDENT APPROACHES, VISUAL SEPARATION
IAD Scenario Arrival Runways Departure Runways
Hourly Rate
ATC Facility
Reported
Model-
Estimated
CURRENT
O
PERATIONS
ARRIVAL PRIORITY
01C, 01L, 01R 30 135 127
DEPARTURE PRIORITY
01C, 01L, 01R 01R, 30 147 152
F
UTURE IMPROVEMENTS 01C, 01L, 01R 01R, 30 N/A 169
VISUAL WEATHER CONDITIONS
Future improvements: Improved Runway Delivery Accuracy,
Wake Recategorization Phase 1.
The capacity rate range for South Flow operations in Visual
con
ditions is 127-135 operations per hour in arrival priority
and 147-152 in departure priority.
The airport operates in the arrival priority configuration
approximately 35% of the time in Visual weather conditions
(totaling 29% annually).
The airport operates in the departure priority configuration
approximately 11% of the time in Visual weather conditions
(totaling 9% annually).
When in departure priority, IAD uses 01R as an overflow arrival
runway. It is assumed that IAD will use all three arrival runways
equally in the future.
Radar separation is used at the Outer Marker and no visual
spacing is allowed behind Heavies or B757s.
MARGINAL – SOUTH FLOW
IAD SCENARIO:
INDEPENDENT APPROACHES, VISUAL SEPARATION
Type Operations Arrival Runways Departure Runways
Hourly Rate
ATC Facility
Reported
Model-
Estimated
CURRENT
O
PERATIONS
ARRIVAL PRIORITY
19C, 19L 30
121 124
DEPARTURE PRIORITY
19C, 19L 19L, 30
118 114
FUTURE IMPROVEMENTS 19C, 19L, 19R 19L, 30
N/A 189
MARGINAL WEATHER CONDITIONS
Future improvements: Improved Parallel Runway Operations ,
Improved Runway Delivery Accuracy, Wake Recategorization Phase
1.
The capacity rate range for South Flow operations in Marginal
conditions is 121-124 operations per hour in arrival priority and
114-118 in departure priority.
The airport operates in the arrival priority configuration
approximately 31% of the time in Marginal weather conditions
(totaling 3% annually).
The airport operates in the departure priority configuration
approximately 7% of the time in Marginal weather conditions
(totaling 1% annually).
No visual spacing is allowed behind Heavies or B757s.
Reduced separation (2.5 NM) between arrivals is authorized for
instrument approaches to Runways 19C and 19L at IAD.
When in departure priority, IAD uses 19L as an overflow arrival
runway. It is assumed that IAD will use all three arrival runways
equally in the future.
The airport has an ADW in place for arrivals to 19R and departures
from 30, which will be used in the future configuration.
MARGINAL – NORTH FLOW
IAD SCENARIO:
INDEPENDENT APPROACHES, VISUAL SEPARATION
IAD Scenario Arrival Runways Departure Runways
Hourly Rate
ATC Facility
Reported
Model-
Estimated
CURRENT OPERATIONS 01C, 01R 30
120 118
FUTURE IMPROVEMENTS 01C, 01L, 01R 01R, 30
N/A 168
MARGINAL WEATHER CONDITIONS
Future improvements: Improved Parallel Runway Operations,
Improved Runway Delivery Accuracy, Wake Recategorization
Phase 1.
The capacity rate range for North Flow operations in Marginal
conditions is 118-120 operations per hour.
The airport operates in this configuration approximately 26% of
the time in Marginal weather conditions (totaling 2% annually).
No visual spacing is allowed behind Heavies or B757s.
Reduced separation (2.5 NM) between arrivals is authorized for
instrument approaches to Runways 01C, 01L, and 01R at IAD.
INSTRUMENT – SOUTH FLOW
IAD SCENARIO:
INDEPENDENT APPROACHES, RADAR SEPARATION
IAD Scenario Arrival Runways Departure Runways
Hourly Rate
ATC Facility
Reported
Model-
Estimated
CURRENT
O
PERATIONS
ARRIVAL PRIORITY
19C, 19L 30
109 103
DEPARTURE PRIORITY
19C, 19L 19L, 30
110 108
FUTURE IMPROVEMENTS 19C, 19L, 19R 19L, 30
N/A 168
INSTRUMENT WEATHER CONDITIONS
Future improvements: Improved Parallel Runway Operations ,
Improved Runway Delivery Accuracy, Wake Recategorization
Phase 1.
The capacity rate range for South Flow operations in Instrument
conditions is 103-109 operations per hour in arrival priority and
108-110 in departure priority.
The airport operates in the arrival priority configuration
approximately 36% of the time in Instrument weather conditions
(totaling 3% annually).
The airport operates in the departure priority configuration
approximately 10% of the time in Instrument weather
conditions, which equates to less than 1% annually.
Reduced separation (2.5 NM) between arrivals is authorized for
instrument approaches to Runways 19C and 19L at IAD.
When in departure priority, IAD uses 19L as an overflow arrival
runway. It is assumed that IAD will use all three arrival runways
equally in the future.
The airport has an ADW in place for arrivals to 19R and
departures from 30, which will be used in the future
configuration.
INSTRUMENT – NORTH FLOW
IAD SCENARIO:
INDEPENDENT APPROACHES, RADAR SEPARATION
IAD Scenario Arrival Runways Departure Runways
Hourly Rate
ATC Facility
Reported
Model-
Estimated
CURRENT OPERATIONS 01C, 01R 30
108 100
FUTURE IMPROVEMENTS 01C, 01L, 01R 01R, 30
N/A 150
INSTRUMENT WEATHER CONDITIONS
Future improvements: Improved Parallel Runway Operations,
Improved Runway Delivery Accuracy, Wake Recategorization
Phase 1.
The capacity rate range for North flow operations in Instrument
c
onditions is 100-108 operations per hour.
The airport operates in this configuration approximately 32% of
the time in Instrument weather conditions (totaling 3%
annually).
Reduced separation (2.5 NM) between arrivals is authorized for
instrument approaches to Runways 01C, 01L, and 01R at IAD.
