SSIM Guide

What is a Slot?

 

According to the IATA World Slot Guidelines, a slot is a permission to operate at a scheduled time of arrival or departure on a specific date and time at an airport.
A slot is not route specific (excluding local rules).

 

When Is Coordination Needed?

 

When the demand of new slots requests exceeds the capacity of the airport infrastructure.

SCR/SMA Messages

The SCR/SMA message consists of 3 components:

  • Message Header
  • Schedule Data Line (1 or more data lines)
  • Message Footer

Example Message

SCR
/
S14
06MAY
SYD
NXX001 XX9999 02JUN25OCT 1234567 180320 DRWDRW0930 1130MELADL JJ
SI IF NOT AVAILABLE PLEASE GIVE NEAREST POSSIBLE
GI KIND REGARDS …….

Message Header

The message header consists of 5 lines, it is the first part of the communication.

SCR – Message Type: SCR, SMA, SAQ, SIR, SHL, SAL, WIR, WCR
/ - Reference Line
S14 – IATA Scheduling Season
06MAY – Date of Message
SYD – Clearance Airport Concerned

Schedule Data Lines

The Schedule Data line contains information that in a specific format. An example of the data elements is shown below.

NXX001 XX999 02JUN25OCT 1234567 180320 DRWDRW0930 1130MELADL JJ
1 2        3          4                       5             6    7     8                        9                      10
NXX001 XX9998 02JUN25OCT 1234567 180320 DRWDRW1930 01301MELADL JJ
                                                                                                                11
NXX003 XX9997 02JUN25OCT 1234567 180320 DRWDRW1030 1230MELADL JJ2
                                                                                                                                     12


    

Decode of Schedule Data Line

  1. Action Code (Action Codes list included below)
  2. Arrival Flight information: Airline designator (2 or 3 letter code), Flight number (maximum 4 numeric)
  3. Departure Flight Information
  4. Start and End date range (must always have an end date)
  5. Days of Week, (Monday =1, Tuesday =2… Sunday =7)
  6. Number of Seats (cargo = 000)
  7. Aircraft Type (IATA subtype codes must be used from Appendix A of the SSIM manual)
  8. Origin and previous station, and the arrival time
  9. Next and final destination, and the departure time
  10. Arrival and departure service type code (see Appendix C of the SSIM manual)
  11. Overnight indictor, the flight is staying at the station over midnight i.e 1 night, 2 nights etc
  12. Frequency rate: The 2 indicates the flight is operating fortnightly (every 2 weeks)

Message Footer

The message Footer maybe composed of supplementary information (SI) or General Information (GI).

SI ALL UTC - supplementary information
GI KIND REGARDS ……. – General information

SCR Examples

New Slot Request for an arrival and departure, all days of the week from 02 June to 25 October.

SCR
/
S14
06MAY
SYD
NXX001 XX9999 02JUN25OCT 1234567 180320 DRWDRW0930 1130MELADL JJ
SI IF NOT AVAILABLE PLEASE GIVE NEAREST POSSIBLE

GI KIND REGARDS …….

New request for a Charter Flight

SCR
/
S14
06MAY
CNS
NXX1351 XX1354 09MAY09MAY 0000500 17673H MNLMNL2130 2315BNEBNE CC
SI IF NOT AVAILABLE PLEASE GIVE NEAREST POSSIBLE

GI KIND REGARDS …….

 

Aircraft Equipment Type Change in Local Time.

SCR
//LT
S14
06MAY
PER
CXX986 XX987 09MAY27JUN 1030507 180320 SYDSYD0905 0945SYDSYD JJ
RXX986 XX987 09MAY22JUN 1030507 220321 SYDSYD0905 0945SYDSYD JJ
SI ALL LOCAL
SI AIRCRAFT CHANGE ONLY – NO TIME CHANGE

GI KIND REGARDS …….

WRONG AIRCRAFT TYPE

It is essential that the specific Aircraft types in Appendix A of the SSIM manual are used and not the aircraft group e.g Do not use 330 instead use 332 or 333 .

SCR
/LT
S14
06MAY
PER
NXX986 XX987 09MAY27JUN 1030507 299
330 SYDSYD0905 0945SYDSYD JJ
SI ALL LOCAL
GI KIND REGARDS …….

CORRECT AIRCRAFT TYPE

SCR
/LT
S14
06MAY
PER
NXX986 XX987 09MAY27JUN 1030507 299
333 SYDSYD0905 0945SYDSYD JJ
SI ALL LOCAL
GI KIND REGARDS …….

New request for Multiple flights (Charter (C), Passenger (J) and Positioning/Ferry (P))

SCR
/
S14
06MAY
PER
NXX152 XX153 14JUL14JUL 1000000 180320 CANCAN0905 0945CANCAN CC
N
XX226 XX227 24JUL26JUL 0004060 180320 SYDSYD0905 0945SYDSYD JJ
NXX2150 XX2157 05AUG05AUG 0200000 220321 CNSCNS0905 1045HNLHNL PC
SI IF NOT AVAILABLE PLEASE GIVE NEAREST AVAILABLE
SI ALL UTC
GI KIND REGARDS ………

Retiming a flight which causes an overnight indictor

If a flight is departing the next day it requires an over-midnight indicator which is after the departure time and before the destination station. The start and end period dates will always correspond to the arrival flight.

SCR
/
S14
06MAY
SYD
CXX123 XX124 14OCT14OCT 0200000 180320 NOUNOU2200 2355NOUNOU JJ
RXX123 XX124 14OCT14OCT 0200000 180320 NOUNOU2200 02551NOUNOU JJ
GI KIND REGARDS …….

Wrong Message

This is a mistake that is common when using the overnight indicator. This example would be a request for an additional flight on arriving on the 15OCT and departing on the 16OCT.

SCR
/
S14
06MAY
SYD
CXX123 XX124 14OCT14OCT 0200000 180320 NOUNOU2200 2355NOUNOU JJ
RXX123 XX124 14OCT15OCT 0230000 180320 NOUNOU2200 02551NOUNOU JJ
GI KIND REGARDS …….

Flight Number, Routing and Service Type Changes

SCR
/
S14
06MAY
SYD
CXX400 XX401 08OCT08OCT 0200000 402744 HKGHKG0420 1050HKGHKG JJ
RXX3522 XX3523 08OCT08OCT 0200000 402744 MNLHKG0420 1050SINHKG GG
SI ALL UTC
GI KIND REGARDS …….

Deleting a flight

SCR
/
S14
06MAY
CNS
DXX1351 XX1354 09MAY09MAY 0000500 17673H MNLMNL2130 2315BNEBNE JJ
SI ALL UTC
GI KIND REGARDS …….

Requesting a new arrival flight

SCR
/
S14
06MAY
CNS
NXX1351 09MAY09MAY 0000500 17673H MNLMNL2130 J
SI IF NOT AVAILABLE PLEASE GIVE NEAREST POSSIBLE
SI ALL UTC
GI KIND REGARDS …….


Requesting a new departure flight

SCR
/
S14
06MAY
CNS
N XX1354 09MAY09MAY 0000500 17673H 2315BNEBNE J
SI IF NOT AVAILABLE PLEASE GIVE NEAREST POSSIBLE
SI ALL UTC
GI KIND REGARDS …….

Optional and Conditional Schedule Information

The additional information is used to present extra information in relation to the slot. For example the flexibility that an airline has for the arrival and departure.

In composing the extra information the following details are required:

  • Start and end with a slash {/}
  • 2 character identifier code is followed by a full stop {.}, the codes are available from Appendix J of the SSIM manual.

In the below example the airline is requesting a new slot on the 12AUG arriving at 0700 and departing at 0855. They have provided additional information which advises the coordinator their flexibility timing range for the arrival and departure. They will only accept offers between 0630 and 0730 for the arrival and between 0825 and 0925 for the departure.

SCR
/
S14
06MAY
SYD
NXX123 XX124 12AUG12AUG 0200000 180320 NOUNOU0700 0855NOUNOU JJ
/FA.06300730 FD.08250925/

Action Codes

N  New Schedule (Code used for a new movement)
C  Schedule to be changed
R Revised schedule (Offer acceptable)
D Delete schedule (Code used to delete existing movement)
E Eliminate schedule (Code used to remove all movements for specific airline for the entire Season or a period or a single date within the Season)
A Acceptance of an offer (No further improvement desired)
P Acceptance of an offer (Maintain as outstanding request)
Z Decline offer

It is recommended that all new users subscribe to the Standard Schedules Information Manual (SSIM), by contacting ssim@iata.org

Reference: IATA Standard Schedules Information Manual (SSIM), March 2014.