AIM Text
- CDRs provide air traffic control a rapid means to reroute departing aircraft when the filed route is constrained by either weather or congestion.
- CDRs consist of an eight-character designator that represents a route of flight. The first three alphanumeric characters represent the departure airport, characters four through six represent the arrival airport, and the last two characters are chosen by the overlying ARTCC. For example, PITORDN1 is an alternate route from Pittsburgh to Chicago. Participating aircrews may then be re-cleared by air traffic control via the CDR abbreviated clearance, PITORDN1.
- CDRs are updated on the 56 day charting cycle. Participating aircrews must ensure that their CDR is current.
- Traditionally, CDRs have been used by air transport companies that have signed a Memorandum of Agreement with the local air traffic control facility. General aviation customers who wish to participate in the program may now enter “CDR Capable” in the remarks section of their flight plan.
- When “CDR Capable” is entered into the remarks section of the flight plan the general aviation customer communicates to ATC the ability to decode the current CDR into a flight plan route and the willingness to fly a different route than that which was filed.
Source: FAA Aeronautical Information Manual · current edition · paragraph 4-4-5.
The short answer
This AIM section is FAA advisory guidance on Coded Departure Routes (CDRs), which give air traffic control a rapid way to reroute departing aircraft when the filed route is constrained by weather or congestion. It explains the eight-character designator format and how general aviation pilots can opt in by entering CDR Capable in flight plan remarks.
Research Notes
Common Questions
What does the eight-character CDR designator mean?
Per the AIM, a CDR is an eight-character designator representing a route of flight. The first three characters represent the departure airport, characters four through six the arrival airport, and the last two are chosen by the overlying ARTCC. For example, PITORDN1 is an alternate route from Pittsburgh to Chicago.
How can a general aviation pilot participate in the CDR program?
The AIM states general aviation customers may enter CDR Capable in the remarks section of their flight plan. This communicates to ATC the ability to decode the current CDR into a flight plan route and the willingness to fly a different route than the one filed.
How often are CDRs updated?
According to the AIM, CDRs are updated on the 56-day charting cycle. Participating aircrews must ensure that their CDR is current before using it for an abbreviated clearance.