In the Lavatory, the water shut-off valve is located:

In the Lavatory, the water shut-off valve is located:

• A. Under the Sink, Behind the Access Door, Below the Water Heater
• B. Behind the Lavatory Mirror
• C. Inside the Overhead Bin
• D. On the Exterior of the Lavatory Door

Answer: (A)

The key idea is that the lavatory water shut-off valve should be quickly reachable by crew from inside the lavatory while staying protected from passenger access. Placing the valve under the sink, behind the access door, just below the water heater meets that need: it sits right where the potable water lines originate, is sheltered inside the cabinet for protection, and remains accessible for a rapid shut-off in case of leaks or contamination. Other locations are impractical: behind the lavatory mirror is hard to reach quickly and not intended for valve operation; inside an overhead bin is not a reliable access point during an emergency; and on the exterior of the lavatory door is exposed and awkward to operate, plus it could be damaged or tampered with.

The key idea is that the lavatory water shut-off valve should be quickly reachable by crew from inside the lavatory while staying protected from passenger access. Placing the valve under the sink, behind the access door, just below the water heater meets that need: it sits right where the potable water lines originate, is sheltered inside the cabinet for protection, and remains accessible for a rapid shut-off in case of leaks or contamination.

Other locations are impractical: behind the lavatory mirror is hard to reach quickly and not intended for valve operation; inside an overhead bin is not a reliable access point during an emergency; and on the exterior of the lavatory door is exposed and awkward to operate, plus it could be damaged or tampered with.