Why are periodic checks of fuel tank sumps and system strainers necessary?

Periodic checks of fuel tank sumps and system strainers are crucial to safeguard the integrity of the aircraft's fuel system. Contamination can occur from various sources, such as water ingress, dirt, and microbial growth. Water can accumulate in fuel tanks, leading to corrosion and the potential for ice formation in colder temperatures. Dirt or particulates can clog fuel filters and strainers, leading to reduced fuel flow and potentially resulting in engine performance issues or failures. By regularly checking sumps and strainers, any contamination can be detected early, allowing for corrective actions to maintain the safety and operational efficiency of the aircraft.

Ensuring compliance with regulations, determining fuel type, and keeping an inventory, while important in their own rights, do not directly address the immediate concerns regarding the safety and functionality of the fuel system as contamination does. Thus, the focus on contamination makes this answer critical for aviation safety.