What does the left Primary Flight Display (PFD) indicate?

The left Primary Flight Display (PFD) is designed primarily to present critical flight information to the pilot, including altitude, airspeed, and attitude, but it also plays a key role in indicating the status of essential systems. In this case, the essential bus power status is particularly important as it informs the pilot about the availability of crucial electrical power systems needed to maintain aircraft operations, especially during critical phases of flight or in the event of a power failure.

Knowing the essential bus power status ensures that the pilot can manage electrical loads effectively and confirm that the aircraft's vital systems remain operational when they are most needed. Understanding this aspect of the PFD is crucial for pilots operating under Part 135 regulations, making this information vital for safety and compliance in various operational scenarios.