Which position is NOT part of the master controller (MC) on the PA5?

The position that is not part of the master controller (MC) on the PA5 is the SLOW speed. In the context of train operations, the master controller manages the various operational modes of the train, including how power is applied and how the brakes are controlled.

The EMER brake position is essential for activating the emergency braking system, which is a critical safety feature. MIN power allows for minimum traction and speed control, useful for smooth starts and gentle operation. MAX power, on the other hand, is necessary for achieving the train's maximum speed and performance in normal operating conditions.

The SLOW speed position, while it may seem like it would be relevant for moving the train at a lower speed, is not classified as a distinct controller position. Rather, slower speeds are typically achieved through adjustments in power settings such as MIN power, rather than a specific "slow" position on the master controller. Thus, it is not recognized as a standard part of the PA5 master control functionalities.