Waste tank negative pressure is provided by cabin differential air pressure when the aircraft is above ______________

Waste tank negative pressure is provided by cabin differential air pressure when the aircraft is above ______________

• A. 12,000 ft
• B. 16,000 ft
• C. 20,000 ft
• D. 28,000 ft

Answer: (B)

Waste tank suction is produced by the difference between cabin pressure and outside air pressure. When the airplane climbs high enough, the outside pressure drops while the cabin is kept at a fixed pressurization, creating a differential that acts like a vacuum on the waste system. The design specifies this suction becomes effective around 16,000 ft, so the waste tank can maintain a negative pressure and function properly. Below this altitude, the differential isn’t large enough to provide reliable negative pressure, so the system relies on other means or the suction isn’t available. Hence, the altitude at which cabin differential provides the waste tank negative pressure is 16,000 ft.

Waste tank suction is produced by the difference between cabin pressure and outside air pressure. When the airplane climbs high enough, the outside pressure drops while the cabin is kept at a fixed pressurization, creating a differential that acts like a vacuum on the waste system. The design specifies this suction becomes effective around 16,000 ft, so the waste tank can maintain a negative pressure and function properly. Below this altitude, the differential isn’t large enough to provide reliable negative pressure, so the system relies on other means or the suction isn’t available. Hence, the altitude at which cabin differential provides the waste tank negative pressure is 16,000 ft.