During the start-up of a TF-2, which switch is NOT required?

The throttle control is not required during the start-up of a TF-2 engine. During the initial start-up phase, the primary focus is on ensuring that the engine fires and reaches idle conditions. The other components listed play crucial roles in this process.

The glow plug engage switch is essential for preheating the combustion chamber, particularly in colder conditions, to facilitate ignition when starting. The starter switch is critical because it initiates the engine's overall starting sequence, engaging the starter motor to crank the engine. Additionally, the fault bypass push button may also be involved to override any system faults that could prevent a successful start.

In contrast, once the engine is running, throttle control can be adjusted as needed but is not necessary for starting the engine itself. This distinguishes the throttle control's function from that of the other switches, which are integral to getting the engine up and running successfully.