Which factor does NOT typically affect the trajectory of mortar fire?

The size of the mortar crew does not typically affect the trajectory of mortar fire. The trajectory, which is the path that the projectile follows, is primarily influenced by physical and environmental factors. These include wind conditions, which can alter the projectile's path; temperature, which affects air density and can influence the performance of the round; and the type of projectile, as different designs have varying ballistic characteristics that can affect how they travel through the air.

In contrast, the size of the mortar crew is more related to operational considerations such as loading, firing, and follow-up tasks rather than the physics that dictate the projectile's flight path. The crew may impact the efficiency and speed of operations, but it does not play a direct role in the trajectory itself.