SSM TIM

SSM TIM sub-types are processed by the system to specifically change flight times at either the departure airport or the arrival airport, or both.

The following scenarios illustrate this functionality.

Two schedules with the same flight number and routing, but with different aircraft types and departure/arrival times on alternate days are updated according to different SSM TIM scenarios below.

Schedule 1 has the following details: Day of Week 135, Aircraft Type 767, Departure 1100, and Arrival 1420.

Schedule 2 has the following details: Day of Week 246, Aircraft Type 757, Departure 1110, and Arrival 1430.

If flight times change on days which fall in both schedules, the change can be made in a single message, if there are no aircraft type or routing changes.

• First scenario: an SSM TIM is received to change the flight times on two consecutive days, 21OCT15 and 22OCT15.
  
  
  As the dates in the SSM exist within different schedule periods, the update causes a split to the original schedules as shown below.
  
  

  Schedule 19OCT15 - 23OCT15 included 21OCT15. As this falls between the start and end date, the schedule is split into three. There are now schedules for 19OCT15 - 19OCT15, 21OCT15 - 21OCT15 and 23OCT15 - 23OCT15. Similarly, the other date in the SSM TIM, 22OCT15, falls between the start and end date of the other schedule period, which is also split into three. There are now schedules for 20OCT15 - 20OCT15, 22OCT15 - 22OCT15 and 24OCT15 - 24OCT15.

  If a schedule has more than one sector (multi-sector) and the times change on one or more sectors, but not the entire rotation then, the SSM TIM can be used to update only those sectors where the times are different. In this example, a schedule exists for flight XS3133A, with a routing SIN-BKK-HKG, and with flight times, SIN 12:00 - BKK 14:00, BKK 15:30 - HKG 19:30.
  
  

  If the times on the first sector change by 45 minutes, but the times of the second sector are unchanged, then the SSM TIM would only need to quote the SIN - BKK sector in the message:

  SSM
  LT
  TIM
  XS3133A
  19OCT15 23OCT15 135
  SIN1245 BKK1445

  A new schedule period is created on the dates specified with new timings on the SIN - BKK sector, but unchanged for BKK - HKG.
  
  

  Changes to times that are part of a schedule is only possible if consistency remains throughout the schedule after the update. If the first sector is changed so that the arrival time at BKK is equal to or later than 15:30, then the timings of the second sector is also changed, as it could no longer have a departure time of 15:30 on the same day.