Control by CTA is a major Free Flight recommendation. Given an arrival slot, the user may determine its own departure time according to its own economic objectives. This departure time would become that flight's Estimated Departure Clearance Time (EDCT). An interim version of this went into effect recently with a new message known as ADJ (adjust), as part of the existing substitution process. The ADJ message permits users to replace the FAA estimated en-route time (ETE) with its own. Eventually, this item will be built into the new CDM message structure. The final version of control by CTAs also requires the implementation of simplified sub rules.

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CTA Status MS Word (16KB) Posted 2/19/99. Memo from Rick Oiesen (Volpe) on the next steps of CTA. Sent with this memo was a 1997 FAA document outlining Estimated Departure Clearance Time [EDCT]/Automated Substitution [SI] Message Processing.	What is CTA? MS Word (10KB) Posted 12/15/98. Memo from Rick Oiesen (Volpe)to start discussion about what is control time of arrival. Outlines a few interpretations of CTA.
Response to What is CTA MS Word (23KB) Posted 12/15/98. Some thoughts by Mike Wambsganss (Metron, Inc.)on what CTA means. In response to Rick Oiesen's memo.