Ground Delay Programs () must be applied to all aircraft departing airports in the contiguous U.S., as well as, from select Canadian airports. Aircraft that have been assigned an in a should not be subject to additional delay. Exceptions to this policy are miles-in-trail and departure/en route spacing initiatives that have been approved by the . procedures do not apply to facilities in Alaska.
A GDP is a TM process administered by the ; when aircraft are held on the ground in order to manage capacity and demand at a specific location, by assigning arrival slots. The purpose of the program is to support the TM mission and limit airborne holding. It is a flexible program and may be implemented in various forms depending upon the needs of the air traffic system. The is calculated based on the estimated time en route and the arrival slot. It is important for aircraft to depart as close as possible to the to ensure accurate delivery of aircraft to the impacted location. s provide for equitable assignment of delays to all system users.
In the past, s were issued manually, followed by software called Groverjack. These systems were based on the Official Airline Guide data, and did not take into account dynamic changes the system users made to their schedule. The Flight Schedule Monitor (FSM) was developed through the collaborative decision making (CDM) process with system users to provide a dynamic method of implementing and managing s. System users submit schedule changes to FSM, which keeps a current up-to-the-minute schedule of flights. The Flight Schedule Analyzer (FSA) is used to monitor and review the effectiveness of s.
- GDP Parameters. Aircraft departing within a defined geographical area are initially assigned delay in the . This area is developed using the FSM, and may consist of one or more s and one or more Canadian airports. All departure aircraft will receive an to the airport.
- Delay Assignment (). A method for assigning delays to aircraft based on the parameters. The delay assignment is calculated in 15-minute increments and appears as a table in TFMS.
- General Aviation Airport Program (GAAP). A method for assigning delays to aircraft based on arrival slot availability at the airport.
- Unified Ground Delay Program (UDP). This program type addresses the mix of scheduled and unscheduled (i.e., pop-ups) demand based on the following parameters: number of reserved pop-ups, target delay multiplier, and delay limit.
- Adjustments. The may make revisions and compressions to the as conditions at the airport or within the airspace change.
- Diversion Recovery. During periods where there are a large number of diverted flights, the may be adjusted to provide priority for the recovery of aircraft diversions over non‐diverted flights.
- User Options. Users are permitted to exchange and substitute Controlled Times of Arrival () congruent with CDM agreements concerning substitutions.
- Conference affected facilities and system users, as appropriate, to determine s and review system demand and other known or anticipated factors.
- Determine when implementation of a is appropriate and the flow rate to be used. Consideration will be given to the impact on other air traffic control facilities and user groups.
- Transmit an advisory providing information to air traffic control facilities and user groups about the implementation, revision, compression, and cancellation of a . Except for the cancellation of a , the advisory must include the following items:
- Delay Assignment Mode.
- Aggregate Demand List (ADL) Time.
- Program Type. (Optional)
- Arrivals Estimated For.
- Program Rate.
- Flights Included.
- Additional Facilities Included.
- Exempt Facilities.
- Canadian Airports Included. (When applicable.)
- Delay Assignment Table Applies To. (Optional.)
- Maximum Delay or Delay Limit. (As appropriate).
- Average Delay. (Optional).
- Transmit the table to TMUs via TFMS and the NADIN circuits, if appropriate.
- Transmit s to s and linked system users.
A CT message is automatically transferred to the 's computers by the ETMS and appears on flight progress strips as an . In the event of a communication failure between the ETMS and the computer, the CT message can be manually entered by the TMC with approval.
Modifications may be made through TFMS.
- Continually monitor, adjust, and cancel s, as appropriate, and transmit an advisory as necessary.
- Provide an or when requested by an .
- Coordinate with affected facilities to ensure the is adequately managing the demand.
- Obtain arrival and departure counts from affected facilities, as appropriate.
- Utilize the and FSM to monitor traffic flow patterns, obtain estimated arrival counts, or obtain airborne delay estimates.
- When appropriate and workload permitting, utilize FSA to monitor the .
The ARTCC TMU must:
- Issue a General Information message (GI) to all towers and s advising of the . In some instances, verbal notification, in addition to a GI, may enhance the dissemination of information.
- Issue information to non-FDEP/FDIO equipped towers and other users in sufficient time for proper planning and control actions. This does not include non-FDEP towers that are satellites of TRACON/RAPCON facilities. The TRACON/RAPCON is responsible for satellite s.
- Evaluate the Delay Assignment Mode and assign s, as appropriate.
- For , assign an using the table to aircraft that do not receive an and are destined to an affected airport within their boundaries. Contact the for aircraft destined to an airport outside their boundaries.
- For GAAP, contact the for an for aircraft that do not receive an .
- Keep the apprised of cancellations and diversions to or from the affected airport.
- Relay information to the when advised by a terminal facility about issues.
- Request a revised from the when notified by the terminal facility that a flight will be unable to depart within parameters as defined in FAA Order JO 7110.65, Air Traffic Control.
- Advise the appropriate terminal facility or controller after receiving a revised from the .
- Utilize FSM to obtain information about the , and may utilize FSA to monitor the .
- Utilize FSM, if available, to obtain information.
- Obtain from the ARTCC TMU and apply the appropriate delay to:
- Ensure that internal flight plans are entered into the computer in order to receive an equitable delay.
- Ensure the is included in the flight clearance when a is in effect. If an is not received and a is in effect, contact the ARTCC TMU for an .
- Issue information to non-FDEP/FDIO equipped towers and other users in sufficient time for proper planning and control actions.
- To the extent possible, plan ground movement of aircraft destined to the affected airport so that flights will meet the parameters in FAA Order JO 7110.65, Air Traffic Control. If unable, advise the , through the appropriate protocol.
- Ensure aircraft with an that are in a Ground Stop are not released without the approval of the issuing authority for the Ground Stop.
- When a is in effect for the local airport, forward the total number of hourly arrivals and departures to the , through the appropriate protocol, as soon as possible after each hour in order that timely adjustments may be made.
- Coordinate closely with the appropriate ARTCC TMU on conditions affecting current or projected arrival rates.
- All requests to amend s earlier than the current must be coordinated with the .
- Facilities without FSM should contact their overlying facility to request a new .
- Modifications to s for a time later than the current must be processed in accordance with the following guidelines:
- The pilot/operator must be in contact with ATC.
- Facilities with FSM may utilize the Change Request (ECR) tool to assign a new utilizing the Slot Credit Substitution (SCS) method, followed by the unlimited delay option, when available.
- If the time generated by ECR is not acceptable (normally two hours of additional delay or longer), the facility must contact the through the appropriate protocol, for a new .
- Conference all affected facilities and system users, as appropriate, to develop an operational plan for release of ground delayed traffic into the system.
- Transmit an advisory stating the has been cancelled. The advisory must include the following items:
- ADL Time.
- Purge flights from the TFMS.
- Issue cancellation information to underlying facilities, using normal communication methods, in sufficient time for proper planning and control actions.
- Notify facility personnel, as appropriate, of the cancellation.
- The must document all pertinent information related to the in their position logs, including, but not limited to, the start and stop times and the reason for the .
- The ARTCC TMU and the Terminal must document all pertinent information related to the .
- Intermediate landing. The flight should land at the intermediate airport to provide the delay necessary for the flight to arrive at the . An intermediate landing airport within the arrival should not be accepted without coordination and approval from the .
- Substitution of flights.
- Users are permitted to exchange and substitute s congruent with CDM agreements concerning substitutions. The may deny substitution requests when:
- Ensure that when flights are traded, the delay factor is equal to the original delay factor after the trade/substitution has been completed.
- Document substitutions.
- Transmit an advisory when substitutions are suspended and include an estimated time when substitutions will resume.