How can the bleed air shutoff valve be closed?

The bleed air shutoff valve can be closed by pulling the engine fire handle. This action is part of the aircraft's emergency procedures designed to contain an engine fire or prevent potential hazards related to a malfunctioning engine. When the fire handle is pulled, it typically triggers a set of actions that include shutting off fuel supply and bleed air, which helps to isolate the affected engine and minimize the risk of further damage or fire spread.

In contrast, other methods listed may not provide the immediate or specific closure of the bleed air shutoff valve. Shutting down the main engine might not directly close the valve, as there may be residual pressures or other factors at play. Pressing a control button could be a possibility, but it generally depends on the specific aircraft system and does not universally apply across all aircraft. Finally, manual operation of the valve is not the standard procedure in emergency situations where rapid action is required, making it less effective in scenarios where immediate response is critical. Thus, pulling the engine fire handle is a definitive and direct means of addressing engine-related emergencies efficiently.