Traffic Management Initiatives (TMIs) such as airport-specific Ground Delay Programs (GDPs) help to balance the demand (of aviation) with its capacity, alongside providing safety, resilience, and effectiveness.
In North America, for example, TMIs are also being modernized through efforts such as data integration in Canada and NextGen in the US.
However, there is a TMI that overrides all other forms. This is known as a Ground Stop (GS). Let's dive into its details.
A Ground Stop (GS) is an air traffic control initiative that requires some aircraft to remain on the ground at the airport where the flight is originating from.
In order to manage the flow of aircraft at a given airport, the FAA Air Traffic Control System Command Center (ATCSCC) can issue a ground stop.
The reasons behind implementing a GS can encompass factors such as the geographical area where an airport is located, the environment, or the equipment.
Ground stops are implemented by the air traffic control during a particular time period. According to the Federal Aviation Administration ( FAA), a Ground Stop, in general, should be implemented in the following conditions:
- "In severely reduced capacity situations (below most user arrival minimums, airport/runway closed for snow removal, or aircraft accidents/incidents);
- To preclude extended periods of airborne holding;
- To preclude sector/center reaching near saturation levels or airport grid lock;
- In the event a facility is unable or partially unable to perform ATC services due to unforeseen circumstances;
- When routings are unavailable due to severe weather; and
- When routings are unavailable due to catastrophic events."
In extreme cases, as was 9/11 ( which changed aviation forever), the entire airspace of the US was closed. The GS also barred all aircraft from flying, necessitating all airborne flights to land. It also was the first nationwide GS in the history of the US.
Looking at the list of reasons why a GS could be implemented, it is clear that it is put in place to ensure everyone's safety. However, passengers who want to catch a connecting flight or are headed to a specific destination with tight deadlines can find it troublesome.
Ground stops lead to delays in departure times and have the possibility of creating a cascading effect, leading to delays and disruptions of flights that are to follow.
A GS could happen mid-flight, in which case the pilot could fly the plane until (s)he receives a signal to land or be redirected to a different airport, airline pilot Gary Baumgardner (an airline pilot with 16 years of experience) told islands.com:
" Flights already in the air heading to an airport with a ground stop may be placed in a holding pattern, where the aircraft circles in a designated area until it's safe to proceed to the airport. If the ground stop is expected to last a long time, flights may be diverted to alternative airports. This adds additional fuel consumption, potential refueling stops, and further delays, affecting passengers' arrival times and potentially leading to a reshuffling of their travel plans. "
The National Business Aviation Association (NBAA) says that it might not be clear in all cases about how long a ground stop will be needed. However, there will always be an update time, which is the duration when the GS will be evaluated for a further extension.
A GS will be described as having a low, medium, or high possibility of extension (POE). The NBAA also warns that the update time is not the same as the Expected Departure Clearance Time (EDCT):
"Facilities may implement ground stops for up to 15 minutes without notifying the Air Traffic Control System Command Center (ATCSCC). A facility ground stop may not exceed 30 minutes. Once the delay is anticipated to reach 15 minutes or more, the ATCSCC is notified. If the ground stop is expected to continue, an advisory will be issued by the ATCSCC advising customers of the extension."
There are three factors that determine the scope of a GS. These include the following:
Distance
Distance is a direct way of measuring the scope of a GS. For instance, if a ground stop is determined as "700 miles + ZOB", it means that all flights originating within 700 miles fromCleveland Air Route Traffic Control Center (ZOB) are a part of the Ground Stop scope.
Center
The second factor that determines the scope of a GS is known as the Air Route Traffic Control Center (ARTCC), which is known as the en-route center. A scope of "ZAN+ZTL+ZFW," for example, captures flights from the following:
- Anchorage Air Route Traffic Control Center (ZAN)
- Atlanta Air Route Traffic Control Center (ZTL)
- Fort Worth Air Route Traffic Control Center (ZFW)
Tier
The tier system while implementing a GS will help in knowing the scope of the Ground Stop. The first tier of a GS represents the area that is in the airport's vicinity.
For example, at the Philadelphia International Airport (PHL), the first tier order for a GS impacts airports as far close as New York in the East, Pittsburgh in the west, and Raleigh in the south, and North Carolina.
The second tier affects flights from the following destinations:
- Atlanta
- Boston
- Chicago
- Cleveland
- Indianapolis
- Miami
A third tier of the GS at PHL prevents all aircraft headed to PHL regardless of the origin.
How is a Ground Stop canceled?
In order to cancel a GS, an ATCSCC must "issue cancelation information to underlying facilities, using normal communication methods, in sufficient time for proper planning and control actions."
Passengers aren't entitled to compensation if a GS occurs due to uncontrollable events such as inclement weather. However, if the complications arise due to factors that are under an airline's control, passengers can get compensation.
