When a Standard Instrument Departure (SID) is assigned, the transition is included if...

When a Standard Instrument Departure (SID) is assigned, the transition is included if it is deemed necessary for the safe and efficient flow of air traffic. The primary goal of providing a SID is to ensure that aircraft can safely depart while integrating into the existing air traffic system.

Including the transition as part of the SID ensures that the aircraft follows a defined route and maintains safe separation from other traffic, especially in busy airspace. This necessity arises from factors such as terrain, surrounding air traffic operations, and airspace structure. Controllers assess these factors when assigning SIDs and will include the necessary transitions to facilitate safe operations.

While pilots can request transitions, and traffic conditions can influence the decision, the overriding reason for including a transition is based on safety and operational requirements. Aircraft weight is less relevant in this context, as it primarily affects performance but not the necessity of a transition in a SID.