Pacer at Charlotte

Dallas Love Airport
Pacer @ CLT Process

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Pacer’s Role in Charlotte


At Charlotte Douglass Airport, CLT, Pacer is deployed in support of NASA’s Airspace Technology Demonstration 2 (ATD-2). NASA developed an integrated arrival, departure, and surface (IADS) concept and technology which has been deployed in the Dallas area. This technology leverages NAS data from FAA systems such as Traffic Flow Management System (TFMS), Time Based Flow Management (TBFM), and Terminal Flight Data Management (TFDM). The IADS system uses this data, along with airline supplied data, to build an integrated schedule in the Dallas area. Pacer supplies the IADS system with GA pilot departure readiness data, further improving the IADS schedule. To learn more about ATD-2, visit NASA’s ATD-2 website.

HERE’S WHAT IS DIFFERENT ABOUT CLT PACER: If a Pacer user submits departure intent for a flight, sometimes referred to as a “ready to taxi time,” they will receive the following information from the ATD-2 surface scheduler via Pacer:

  • Expected departure runway – the runway that ATC has indicated you should expect for departure; it is subject to change.
  • Target Take Off Time (TTOT) – the time the ATD-2 scheduler has computed you will be wheels-up based upon the time you indicated you will be ready to taxi (departure intent time you submitted). The TTOT considers all of the traffic at CLT around your time of departure, so it is a good indication of how long it will take you to get airborne from the time you leave the ramp.
  • Traffic Management Initiatives (TMIs) – Pacer will use ATD-2 data to provide you with a statement indicating whether you should expect any type of traffic management assigned departure time. This is typically based upon high demand along your route or at your destination (more detail below).

HOW DOES PACER HANDLE ‘BLOCKED’ FLIGHTS? If you are submitting a departure intent time for an aircraft call sign that is on the FAA’s Limited Aircraft Data Display (LADD) list, formerly known as the BARR list, Pacer will not display any of the above data fields.

HOW DO I LET AUTHORIZED PACER USERS TO SEE DATA FOR A ‘BLOCKED’ FLIGHT? Request a waiver by writing to The requestor must provide the callsigns of their ‘blocked’ aircraft and the Pacer account email addresses for the persons they want to receive the data. Once the waiver request is completed, a MITRE Pacer team member will contact the requestor to verify the information. After approval, the designated Pacer users will be able to receive the ATD-2 surface scheduler data for the waived callsigns.

MORE INFORMATION about Traffic Management Initiatives (TMIs): The bold text will be shown in Pacer based upon the condition in italics…

  • Flight has an EDCT and no TMIs >> “There is a ground delay program in effect for your destination or route. Expect to be assigned an EDCT.”
  • Flight has an EDCT and some (one or multiple) TMIs applied >> “There may be delays for your route. Contact ATC for more information.”
  • Flight has no EDCT, and has exactly one TMI, If that one TMI is an APREQ >> “There may be delays for your route. Contact ATC prior to engine start.” Note: In this case, the flight’s TTOT is presented as “Earliest wheels up time”, rather than “expected wheels up time”
  • That one TMI is not an APREQ (e.g. Miles-In-Trail) >> “There may be delays for your route. Contact ATC for more information.”
  • Flight has no EDCT, more than one TMI applied >> “There may be delays for your route. Contact ATC for more information.”

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