The ABCs of EDCTs

Welcome back to Jump Seat. A busy spring and summer season is on tap which can lead to significant delays in the U.S. domestic airspace. With numerous factors that can significantly impact operations, preparation is key. Today, we will dive into one of those disruptors - the EDCT. 

What is an EDCT?  

An EDCT, or Expected Departure Clearance Time, is a time slot for departure assigned to the aircraft usually due to a traffic initiative at the arrival airport or en route airspace. EDCTs can be issued by the local tower, TRACON, ARTCC, or the Command Center themselves. The cause could be one, or a combination of, traffic volume exceeding thresholds at the airport, en route or on-site weather, equipment or power outages, aircraft accidents, or special events. EDCTs are difficult to forecast; however, a little research and initiative beforehand could make a difference. Learn more below on how you can navigate EDCTs and prepare your operation accordingly. 

What causes EDCTs? 

Weather: Operations are impacted by weather on any given day. Specifically, convective weather is the common cause for weather-related delays. For safety reasons, a controlling center may initiate a Ground Delay Program, or GDP, to let the weather run its course. GDPs differ from Ground Stops, as the time issued for the latter is a “refresh time” in which ATC will make a decision about the delay. Options into the affected airports during Ground Stops are non-negotiable, but for GDPs, we are able to check in with Command Center and request relief. This is commonly known as a TCA request. GDPs are common in regions where convective activity is frequent but are not limited to just convective weather. Low ceilings can also create significant delays, especially in areas like San Francisco during the early Spring and Summer mornings. There, operators can experience long durations of low ceilings and fog, which typically will mandate a GDP. 

Figure 1: The ARINCDirect Thunderstorm forecast layer can provide a peek into the future on potential convectivity-related delays en route or at the destination airport. This particular forecast shows a concentration of significant vertical velocity and tops over southern Florida which could potentially lead to traffic initiatives such as a Ground Delay Program for 1600Z time frame over certain southern Florida airports. 

Volume: Similar to rush-hour traffic, controlled airspaces can experience congestion during popular time frames, holidays, and seasonal months. During the winter and early spring months in the United States, a high volume of travelers fly from the U.S. Northeast region down to the U.S. Southeast and Caribbean regions, bearing the nickname “snowbirds.” Additionally, holidays, summer weekends, and Fridays are known to feature a higher-than-average number of flights up and down the eastern U.S. seaboard. Airports in the New York Metro, Florida, and the Caribbean will experience a surplus of demand traffic, usually over-exceeding regular capacity thresholds, or airport arrival rates. This alone could necessitate the need for GDPs. EDCTs are then allocated based on the predicted time demand falls below threshold lines. 

Figure 2: On this particular day, the demand had exceeded the threshold during the hours of 1800-2100Z. Coupled with significant weather, a Ground Delay Program could have very well been assigned. 

Flow Constrained Areas: These delays are based on en route conditions and the congestion of traffic within that airspace. Therefore, variables such as weather and staffing can significantly influence the decision for a traffic initiative. Examples of common AFPs are FCAJX7, typically issued during Winter and Spring when volume picks up from the Northeast towards warm weather destinations, and FCADC7, frequently published during convective afternoon thunderstorms affecting the mid-Atlantic and Northeast destinations. Controlled airspaces may also become constrained if en route weather forces traffic towards one direction, thus concentrating traffic at a certain area of the airspace. These AFPs are based on predicted demand and the nature of the weather phenomena, therefore EDCT durations may be revised throughout the day.

Figure 3: Airspace flow programs FCADC7 (orange line) and FCAID1 (red line) that capture traffic coming in from Cleveland and Indianapolis centers into the mid-Atlantic and U.S. Northeast. At times, multiple AFPs could make route-outs too lengthy to circumvent. 

Figure 4: Typical route-out options for an AFP such as the JX5/JX7. These routes serve as options for Florida-bound flights from the U.S. Northeast as a result of the JX5 closing off passage through the ARs and northern Florida. This route has been nicknamed the WATRS route and will commonly include waypoints that are east of the ARs. It circumvents the JX5 segment to the east and therefore exempts flights from an EDCT.  

Figure 5: FCAJX5 (red line) that captures any traffic going southbound towards ZMA from ZJX/ZTL/ZHU. Notice the orange line north/northeast of the Bahamas falls just east of the JX5 line. This route-out option, commonly known as the WATRS route, can circumvent the JX5 AFP. 

Special Events: A recent example of a special event was the Masters PGA Tournament in Augusta, GA in early April. EDCTs were implemented due to the increased volume of flights to airports in the Augusta region. In anticipation of this, the FAA pre-released special routing in and out of selected airports to aid in the efficiency of handling traffic. Those who had these special routes filed, and filed early, were issued a shorter EDCT duration.  

What’s next? 

Stay tuned for our next article in this series that will dive into the mitigation options once an EDCT is incurred and how to minimize your changes of receiving an EDCT overall. In the meantime, reach out to our team of Flight Coordinators at +1-410-266-2266 or [email protected]. 

The ARINCDirect team includes a group of flight coordinators that are certified FAA aircraft dispatchers. Some of these coordinators are dually skilled with Meteorology degrees. Meet one of our meteorologists: Ernest Dela Pena, a graduate of UCLA’s Atmospheric Science program who was recently certified by Sheffield School of Aeronautics as an FAA aircraft dispatcher. Ernest’s career with Collins Aerospace started in 2018 in Houston, TX with the former International Trip Support team. There, Ernest was able to refine his forecasting skills and absorb the business aviation landscape. Upon moving to Annapolis, MD to support the Flight Operations team, Ernest has gained more experience by learning from skilled teammates and interacting with more operators around the globe. Because of his dedication to ARINCDirect customers, Ernest is a semi-finalist for a Collins Customer Service Excellence Award. His contributions are a great example of the exemplary value ARINCDirect strives to provide to our valued customers.  

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