Where is the water / waste quantity gauge located?

• A. Overhead panel
• B. Flight deck
• C. Cabin ceiling panel
• D. Control panel in 2L

Answer: (D)

The main idea is where cabin crew need quick, regular visibility of how much potable water is left and how full the lavatory waste tanks are. That kind of status information is most useful in the cabin, not the flight deck or hard-to-reach areas. Placing the water and waste quantity gauge on the control panel in 2L makes it easily accessible to crew during service, refilling, and waste management, so they can monitor and respond without leaving the galley area or climbing to overhead or ceiling panels.

Overhead panels and cabin ceiling panels are not practical for this purpose—they’re less accessible during service and aren’t standardly used for monitoring potable water or lavatory waste. The flight deck is meant for pilots and flight-critical systems, not routine cabin service gauges. So the control panel in 2L is the most logical, convenient spot for this gauge.