What happens when the TOGA buttons are pressed prior to takeoff?

When the TOGA (Takeoff/Go Around) buttons are pressed prior to takeoff, they serve multiple critical functions that enhance flight safety and performance. Primarily, pressing the TOGA buttons activates the autopilot's command for takeoff mode. This action provides command bars in the TO/TO mode on both Primary Flight Displays (PFDs), which visually assist the flight crew during the initial phase of takeoff by indicating the required flight path.

In addition to this, pressing the TOGA buttons also initiates the engine start sequence. This is crucial as it allows the engines to reach the necessary thrust settings for takeoff. The combination of these two functionalities is essential for a safe and effective takeoff, ensuring that both the pilots have the necessary guidance and the engines are prepared to deliver maximum thrust when needed.

By understanding these dual functions, pilots are equipped to respond adequately during the critical takeoff phase, ensuring both operational readiness and adherence to safety protocols.