Final answer:
When the pilot is at the aircraft line-up, they press the TOGA switch to engage the takeoff thrust mode and confirm the engines are producing the required thrust for takeoff. This procedure is critical for a successful takeoff.
Step-by-step explanation:
When the pilot is at the aircraft line-up and prepares for takeoff, they will press the Takeoff/Go-around (TOGA) switch. The TOGA switch is typically located on the throttle quadrant and is used to engage the takeoff thrust mode of the aircraft's engines. It provides maximum power for a safe takeoff.
Pressing the TOGA switch allows the pilot to confirm that the engines are producing the required thrust for takeoff. It also triggers various automatic systems in the aircraft to set the correct takeoff configuration, such as deploying the flaps and adjusting the flight control surfaces.
This procedure is critical in ensuring a successful takeoff and is an integral part of the pre-flight checklist for pilots.