General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

Which component is affected when the ENG fire switch is activated?

1. Fuel transfer pumps

2. Engine bleed air valves

3. Only the engine fuel valves

4. Power to cabin lights

The correct answer is: Engine bleed air valves

When the engine fire switch is activated, it specifically affects the engine bleed air valves. The engine fire switch is part of the aircraft's fire protection system and is designed to mitigate the effects of an engine fire. When engaged, it typically closes the engine bleed air valves to prevent the spread of fire by stopping the supply of bleed air to the engine components. In contrast, while fuel valves may also be shut off during a fire event, the specific action taken by the fire switch primarily includes closing the bleed air valves to limit airflow that could potentially feed the fire or fuel the combustion process in the engine. Additionally, the system does not directly impact the cabin lights or fuel transfer pumps in the same immediate manner as it does the bleed air system. Thus, the primary function of the engine fire switch is to ensure that the bleed air supply is terminated in response to an engine fire alert.