What is the purpose of using a dark water-soluble dye solution in liquid aircraft systems?

The use of a dark water-soluble dye solution in liquid aircraft systems serves a very practical purpose: making leaks or plugged drop pipes easy to identify. When a dye is introduced into the liquid system, it allows for clear visual confirmation of how the liquid is flowing and whether it is leaking from any point. This is particularly important for maintenance and inspections, where identifying and diagnosing issues quickly can save time and resources.

By coloring the fluid, any abnormalities in the system, such as leaks, clogged pipes, or irregular flows, become apparent. This visibility is crucial for ensuring operational safety and efficiency. The dye solution provides a straightforward method for technicians to find and address potential problems, thereby maintaining the integrity of liquid systems on aircraft.