According to FAA regulations, when must the bulbs of aviation warning lights on water storage tanks be replaced?

The correct choice highlights the importance of reliability and safety in aviation operations. According to FAA regulations, bulbs of aviation warning lights must be replaced before they reach 75% of their life expectancy. This proactive approach ensures that the lights remain functional and visible, which is critical for aircraft safety, particularly in areas with water storage tanks that might pose hazards to flying.

Replacing bulbs before they reach this threshold minimizes the risk of failure during operation, as lighting is essential for alerting pilots to the presence of obstacles. The rationale behind this regulation centers on maintaining optimal visibility and compliance with safety standards. With a replacement strategy that prioritizes this 75% marker, operators can effectively manage maintenance schedules and ensure continuous operation of critical warning systems, helping to prevent dangerous situations related to low visibility or unexpected obstacles.