Section 8. Flow Evaluation Area (FEA), Flow Constrained Area (FCA), and Integrated Collaborative Rerouting (ICR)


FEAs and FCAs support common situational awareness and provide customers increased flexibility in responding to conditions in the (NAS) by providing a graphical description of a constraint and an associated list of flights that traverse the area identified. FEAs and FCAs provide reroutes which are published through a reroute advisory with an optional flight list attached. Stakeholders can monitor FEAs and FCAs through the reroute monitor in traffic situation display the TSD, the Web situation display (WSD), or the collaborative constraint situation display (CCSD).

  1. Default route: A route published by the ATCSCC in conjunction with user preferred trajectory (UPT) for facilities to assign any aircraft that remain on the dynamic list.
  2. Dynamic list: A list of flights captured in an FEA/FCA that is continually updated as changes occur to the aircraft's route of flight.
  3. Early Intent (EI): Customer route preference submitted to the Traffic Flow Management System (TFMS). EI routes identify routing preferences or remove the flight from the constrained area. Customers are expected to file their flight plans in accordance with EI unless otherwise coordinated with the ATCSCC.
  4. EI Window: Time period when customers can submit EI or file out of the FEA.
  5. FCA: The defined region of airspace, flight filters, and time interval used to identify flights subject to a constraint. System stakeholders may be required to take action to mitigate the constraint identified by the FCA.
  6. FEA: The defined region of airspace, flight filters, and time interval used to identify flights. An FEA should be used by system stakeholders to evaluate and/or mitigate potential or existing constraints.
  7. FEA/FCA flight list: Aircraft that penetrate the FEA/FCA during the specified valid time.
  8. ICR: Strategic process for stakeholders to define and structure TMIs to mitigate constraints identified by an FEA or FCA.
  9. Route guidance: Suggested reroutes, issued in an advisory that suggest or provide examples of routing possibilities away from a defined constraint associated with an FEA/FCA. This guidance may not provide routes for all flights captured in the FEA/FCA.

Customers are expected to:

  1. Enter the FCA name in the remarks section when filing the flight plan.
  2. Review advisories and examine their affected flights.
  3. Use EI capability as needed, considering FAA route guidance. Early filing of a flight plan may be used in lieu of this requirement.
  4. Examine their affected flights and submit decisions for routing in accordance with the FEA/FCA. If unable, coordinate with the ATCSCC Tactical Customer Advocate.
  5. Consider using private FEAs to monitor a situation and evaluate an area of concern.
  6. Evaluate and select routes that meet their objectives.


Customers may identify available routes via the Route Options Generation (ROG).

  1. The FAA TMU must:
  1. Remain cognizant of operational areas of interest and use FEAs to evaluate those areas.
  2. When naming FEAs that will be shared, ensure the name is descriptive to the constraint or airspace captured. Ensure FEAs do not contain FCA in the name and do not begin with a number or special character.
  3. Share FEAs with the ATCSCC that may require implementation of TMIs (i.e., reroutes, miles-in-trail, ground stops, etc.) If requesting a reroute in conjunction with a shared FEA, notify the ATCSCC via the NTML of the FEA and the proposed reroute.
  4. Contact the ATCSCC to coordinate a public FEA or an FCA.
  5. Coordinate public FEAs and FCAs with facilities within their area of jurisdiction.
  6. Monitor the FCA dynamic list. Based on information provided in the FCA advisory, appropriate action must be taken in regard to flights that remain on the list.
  7. Monitor the system impact of the routes and contact the ATCSCC if these routes will cause a local flow issue.
  8. Coordinate with the ATCSCC if it becomes necessary to issue an FCA.
  9. Monitor the public FEA or FCA and, as required, coordinate modifications to the initiatives with the ATCSCC.
  10. When an FCA is used to manage a constraint; review the advisory issued by the ATCSCC and comply with the provisions of the advisory.
  11. When TMIs that impact other stakeholders will be required to resolve a situation:
  1. Coordinate with the ATCSCC.
  2. Provide local information which aids the ATCSCC with developing successful reroute options for customers to consider.
  3. Monitor impacts of customer preferences.
  4. Take tactical action as necessary.
  1. Assign default routes to flights that are not routed around the constraint as directed in reroute advisories.
  1. The ATCSCC must:
  1. Issue public FEAs and issue an advisory, as necessary. Public FEAs must have a descriptive name that is pertinent to the event.
  2. Issue FCAs and, issue an advisory, as necessary. Include in the advisory any actions required by customers and field facilities.
  3. Create FEAs that define the geographical area of concern with appropriate altitude and time limits, plus any other relevant filters to select affected traffic.
  4. Monitor the NTML and respond to field facility requests for reroutes associated with shared FEAs. Evaluate reroute requests and, if applicable, conference the appropriate stakeholders to coordinate the reroute.
  5. Issue any associated routes via the “Create Reroute” tool.
  6. Ensure the FCA or public FEA expires at the end of the published valid time unless coordination is accomplished and an advisory issued that cancels the initiative.
  7. Provide FAA facilities with guidance on the use of default routes and when they may be discontinued.

These procedures must be utilized in the development and coordination of ARTCC to ARTCC and ARTCC to N90 MIT.


ARTCC TMU must follow guidelines for the FEA naming convention as follows:

  1. For Airport MIT:


  1. For Airway/Route:


  1. ZDC_ZJX_J55
  2. ZNY_N90_PARKE

The ARTCC TMU must:

  1. Draw the FEA at the common ARTCC or ARTCC/N90 boundary.
  2. Draw the FEA per route.
  3. Filter the FEA for single airport destinations, except where MITs are requested for multiple destinations in an `as one' restriction; in which case, the FEA must be filtered to reflect that information.
  4. Review the total number of aircraft as presented in the 15-minute FEA/FCA timeline bar.
  5. Select and review the FEA/FCA Dynamic List for restrictions needed based on distance between aircraft, making sure the “ENTRY” column is set to display aircraft in chronological order of times as they enter the FEA.
  1. An accepted distance consideration for the en route environment is 7 miles per minute of flight time.


Two aircraft passing through an FEA 3 MINITs should be considered to be 21 MITs of one another.

  1. An accepted distance consideration for N90 TMIs is 5 miles per minute of flight time.
  1. Complete electronic coordination and share the FEA with the ATCSCC as required.
  2. Continually evaluate and assess MIT for effectiveness and cancel the restriction at the earliest opportunity.
  1. Customers are expected to:
  1. Examine their affected flights and, when practical, enter early intent (EI) and/or file a flight plan that will route the aircraft away from the affected area. When acceptable options are not available, contact the ATCSCC Tactical Customer Advocate.
  2. Enter “NRP” in the remarks section of the flight plan.
  1. The FAA traffic management unit (TMU) must:
  1. Coordinate with the Air Traffic Control System Command Center (ATCSCC).
  2. Provide assistance in developing flow constrained areas (FCA), reroute options, and associated restrictions for the impacted area.
  1. The ATCSCC must:
  1. Issue an ICR FCA that defines the geographical area of concern with appropriate altitude and time limits, plus any other relevant filters to select affected traffic.
  2. Conference the affected stakeholders and communicate the objectives for the flights captured in the FCA.
  3. Send a numbered advisory that provides route guidance, if deemed necessary.
  4. Issue an advisory in the Create Reroute tool. Preferential routes, recommended routes, and constraint avoidance may be suggested.


Required reroutes may not be necessary if the response taken by customers alleviates the need for this initiative or the reason for initiating the ICR process changes (weather does not materialize, significant volume reductions, etc.).

  1. The FCA expires at the end of the published valid time unless it is coordinated and an advisory is issued that extends or cancels the initiative.