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GCR Messages

GCR messages (General Aviation Slot Clerrance Request) allow to reserve slots at airports. They use internationally valid format described below. To send a GCR right-click on the flight and select SHOW SCHEDULE. In the drop-down box select GCR. The content window automatically displays the default information basing on the selected flight. To send the message you need to add the recepient's email address at the bottom of the pop-up window.


Single message may include requests on as many flights as needed given that all those flights take place on the same calendar day. The GCR message only uses ICAO codes for aircraft and airports and displays UTC times only.
GCR message example - flights on the same day
GCR message example - flights on different days
GCR example - flights on the following days



/REG or /FLT - aircraft registration or flight number

EPWA - airport at which slots are being requested

N BARTI 02MAR 001F900 0800EPPO P - flight details: N (action code) BARTI (flight identification) 02MAR (date of operation) 001F900 (PAX number + Aircraft type) 0800EPPO (Origin airport (ICAO) + Scheduled Time of Arrival) P (type of flight)

SI … - (optional) additional information in free text

GI BRGDS - general information in free text

For an arrival slot, there is NO blank between the action code and the flight identification (NBARTI) . The scheduled time of arrival is stated AFTER the airport of origin, without a blank in between.

For a departure slot, there is A BLANK between the action code and the flight identification (N BARTI). The scheduled time of departure is stated BEFORE the destination airport, without a blank in between.

The action code defines the exact intention of the GCR message sender and is always at the beginning of the line. Depending on the sender, the following codes are possible: N– New Schedule; D– Delete Schedule; C– Schedule to be changed; R– Revised Schedule.

Flight types: D- General Aviation Flight; W- Military Flight; I- Air ambulance; P- Positioning/Ferry/Delivery/Demo Flight; H- Cargo Flight; T- Technical Flight; K- Training Flight; N- Other; if the box 'Commercial' is unticked the flight type will display D.

On the attached screenshots you can find examples of GCR messages.

  • Flights on the same day - select the airport and Leon will show all flights from/to that airport.
  • Flights on different days - Leon will show only flights on the next day, omitting the following days.
  • Flights on the following day/days - when marking 2,3 days (or more) and selecting an airport, if flights are not on the first marked day but on the following day/days - Leon will show flights i.e. on the 2nd marked day omitting the 3rd marked day.

Below you can find an example of GCR message email.

If the format of the GCR message is invalid, Leon will highlight the content in red and will show a warning: GCR message has invalid format, probably header or footer mismatched.

The default message content can be inserted manually, however, the format still applies.

updates/a-new-functionality-of-sending-gcr-messages-from-leon-has-been-implemented.txt · Last modified: 2017/02/21 21:10 by bartek