Because captain sits on the left, left-hand traffic patterns are more common. In order to avoid a head-on collision, each airplane must turn right. Since the captain sits on the left, they will have an unrestricted view of the other airplane, and therefore can assess the situation easily.

The convention of pilots sitting on the left side (specifically the Pilot-in-Command or PIC) dates back to early aviation and the establishment of left-hand traffic patterns. Because most early aircraft had a natural tendency to turn left due to the torque and P-factor of their engines, pilots found it aerodynamically easier to make left turns. Consequently, sitting on the left provided the best visibility of the runway and other aircraft during these standard left-hand circuits. This practice was further solidified by the design of early two-seater aircraft like the Wright Model A, which placed controls for the left seat. While modern aircraft are balanced and technologically advanced, the tradition remains a worldwide safety standard, allowing for consistent cockpit layouts and better visual referencing for captains during critical phases of flight like landing and taxiing.