Commercial Pilot License (CPL) Practice Exam

Turning the master switch OFF is the appropriate action to take in the event of an electrical fire in an aircraft. This action helps to immediately cut off the electrical power supply, which significantly reduces the risk of worsening the fire by eliminating further sources of electricity that could fuel the flames. Since electrical fires can escalate quickly, promptly de-energizing the affected systems is crucial for ensuring the safety of both the crew and passengers. Checking fuel levels, increasing engine power, or opening air vents could either distract from the primary need to address the fire or inadvertently contribute to more hazardous conditions. For instance, checking fuel levels does not address the immediate threat and may take precious time away from managing the emergency. Increasing engine power can potentially complicate the situation and generate more heat, while opening vents could introduce additional oxygen to the fire, exacerbating the situation. Thus, turning off the master switch is a direct and effective method to manage an electrical fire in-flight.