11.17 Water and Waste

Question 1

What are the three subsystems of the aircraft water and waste systems?
A) Fuel, Hydraulic, Electrical
B) Potable water, Toilet, Wastewater
C) Cabin air, Drainage, Engine coolant

Answer 1

B) Potable water, Toilet, Wastewater

Question 2

What is the purpose of the potable water system?
A) To dispose of toilet waste
B) To provide water to engines
C) To store, deliver, monitor, and control drinkable water

Answer 2

C) To store, deliver, monitor, and control drinkable water

Question 3

Where is potable water typically stored on an aircraft?
A) In the wing tanks
B) Below the cabin floor, usually in cargo area sidewalls
C) Above the passenger cabin

Answer 3

B) Below the cabin floor, usually in cargo area sidewalls

Question 4

What is commonly used to pressurise the potable water tanks?
A) Cabin air conditioning
B) Aircraft pneumatic system or electric pump system
C) Fuel boost pumps

Answer 4

B) Aircraft pneumatic system or electric pump system

Question 5

What do the air filters in the water pressurisation system prevent?
A) Overfilling of water tanks
B) Fuel contamination
C) Contamination and dirt entering the potable water system

Answer 5

C) Contamination and dirt entering the potable water system

Question 6

What component prevents over-pressurisation of the potable water tanks?
A) Mixer valve
B) Drain mast
C) Pressure relief valve

Answer 6

C) Pressure relief valve

Question 7

Where are potable water system distribution lines typically routed?
A) Through landing gear bays
B) Behind cabin ceiling panels
C) Inside engine nacelles

Answer 7

B) Behind cabin ceiling panels

Question 8

How is freezing in water lines prevented in cold fuselage sections?
A) By using refrigerant lines
B) By closing all valves
C) By using insulation, heat tapes, inline heaters, and heated hoses

Answer 8

C) By using insulation, heat tapes, inline heaters, and heated hoses

Question 9

When must the potable water system be completely drained?
A) During refueling
B) When the aircraft is parked in freezing weather
C) After every flight

Answer 9

B) When the aircraft is parked in freezing weather

Question 10

What does the fill/overflow valve do?
A) Prevents reverse air pressure
B) Allows filling of the potable water system
C) Controls cabin air temperature

Answer 10

B) Allows filling of the potable water system

Question 11

What activates the infrared faucet in a lavatory?
A) A manual handle
B) A push-button
C) A reflective sensor unit

Answer 11

C) A reflective sensor unit

Question 12

What is the capacity of a typical lavatory water heater tank?
A) 5 litres
B) 1.5 litres
C) 10 litres

Answer 12

B) 1.5 litres

Question 13

How is wastewater drained from the aircraft in an overboard system?
A) Through engine exhaust
B) Into fuel tanks
C) Through drain masts

Answer 13

C) Through drain masts

Question 14

What helps generate wastewater flow in flight?
A) Engine thrust
B) Differential pressure between cabin and drain mast
C) Gravity only

Answer 14

B) Differential pressure between cabin and drain mast

Question 15

What are the three positions of a lavatory drain valve?
A) OPEN, CLOSE, AUTO
B) ON, DRAIN, OFF
C) PRESSURE, VACUUM, BYPASS

Answer 15

B) ON, DRAIN, OFF

Question 16

What is the primary function of the toilet waste system on an aircraft?
A) To provide potable water to the lavatory
B) To collect and store waste from toilets in waste tanks
C) To monitor cabin air pressure

Answer 16

B) To collect and store waste from toilets in waste tanks

Question 17

What are the two main types of toilet waste systems found on aircraft?
A) Gravity and pressurized systems
B) Modular and centralized systems
C) Flush motor toilets and vacuum toilet systems

Answer 17

C) Flush motor toilets and vacuum toilet systems

Question 18

Where is the waste holding tank typically located in a modular lavatory installation?
A) In the cargo hold
B) Inside the lavatory unit itself
C) Behind the cockpit bulkhead

Answer 18

B) Inside the lavatory unit itself

Question 19

What component is used to attach a modular lavatory unit to the aircraft structure?
A) Adhesive mounts
B) Riveted joints
C) Tierods

Answer 19

C) Tierods

Question 20

What initiates the flush in a flush motor toilet?
A) A proximity sensor
B) A timer activated by the flush handle
C) A manual lever under the toilet

Answer 20

B) A timer activated by the flush handle

Question 21

What type of pump is used in a flush motor toilet system?
A) Piston pump
B) Gear pump
C) Impeller pump

Answer 21

C) Impeller pump

Question 22

What type of motor is used in a flush motor toilet?
A) Single-phase AC motor
B) DC stepper motor
C) High-power three-phase electric motor

Answer 22

C) High-power three-phase electric motor

Question 23

What is the typical flush duration in a flush motor toilet system?
A) 3–5 seconds
B) 8–12 seconds
C) 15–20 seconds

Answer 23

B) 8–12 seconds

Question 24

How many uses can a flush motor toilet system generally support before needing to be drained?
A) About 50 times
B) About 75 times
C) About 100 times

Answer 24

C) About 100 times

Question 25

What component controls a vacuum toilet flush operation? A) Flush handle timer B) Cabin pressure sensor C) Flush Control Unit (FCU)

Answer 25

C) Flush Control Unit (FCU)

Question 26

Where are the vacuum toilet waste tanks typically located? A) In the overhead cabin B) In the cargo compartment C) Behind the forward lavatory

Answer 26

B) In the cargo compartment

Question 27

What safety system shuts down the vacuum toilet system when the tanks are full? A) Mechanical override switch B) Electronic control module C) Emergency dump valve

Answer 27

B) Electronic control module

Question 28

What phenomenon can occur if there is a leak in the waste drain valve at altitude? A) Hydraulic failure B) Cabin decompression C) Blue Ice

Answer 28

C) Blue Ice

Question 29

What tool is used to drain a flush motor toilet waste tank? A) A central valve handle B) A spring-loaded telescoping guide tube C) A foot-operated lever

Answer 29

B) A spring-loaded telescoping guide tube

Question 30

How much chemical solution is added to a flush motor waste tank after servicing? A) 5–10 litres B) 13–31 litres C) 40–55 litres

Answer 30

B) 13–31 litres

Question 31

What is the purpose of the separator in the latest waste holding tanks? A) To clean the tank walls B) To block odours from escaping C) To allow particle-free vacuum air to be expelled

Answer 31

C) To allow particle-free vacuum air to be expelled

Question 32

What must be worn when handling toilet cleaning chemical solutions? A) High-visibility clothing B) Ear protection C) Personal Protective Equipment (PPE)

Answer 32

C) Personal Protective Equipment (PPE)

Question 33

What is the main risk of chemical cleaning solution contact? A) Electrical shock B) Frostbite C) Skin and eye irritation or burns

Answer 33

C) Skin and eye irritation or burns

Question 34

How is the waste tank of a vacuum toilet system accessed for servicing? A) Through the cockpit B) Via a service cart panel in the galley C) From a central waste panel on the lower fuselage

Answer 34

C) From a central waste panel on the lower fuselage

Question 35

What is done after all T-handles are pushed up during vacuum toilet servicing? A) Immediately disconnect the hose B) Wait one minute before removing the waste hose C) Rinse with additional water

Answer 35

B) Wait one minute before removing the waste hose

Question 36

Why must rinse lines be drained before closing the rinse fitting cap? A) To prevent odour buildup B) To avoid electrical faults C) To prevent freezing

Answer 36

C) To prevent freezing

Question 37

What is a major threat posed by undetected corrosion in aircraft structures? A) Increased engine vibration B) Decrease in fuel efficiency C) Decrease in load-carrying capacity leading to cracks

Answer 37

C) Decrease in load-carrying capacity leading to cracks

Question 38

Why are lavatory and galley areas especially susceptible to corrosion? A) They are not made of aluminium B) They are exposed to constant vibration C) They are frequently exposed to water

Answer 38

C) They are frequently exposed to water

Question 39

What structural material is significantly more resistant to corrosion than aluminium? A) Steel B) Titanium C) Copper

Answer 39

B) Titanium

Question 40

What is one function of built-in catch basins and drains in lavatory and galley areas? A) To collect waste fluid for recycling B) To direct water flow and reduce corrosion C) To store spare fluids for maintenance

Answer 40

B) To direct water flow and reduce corrosion

Question 41

What often signals corrosion or leaks under lavatories or galleys? A) Cabin humidity B) Water from lower bilge drains C) Engine performance drop

Answer 41

B) Water from lower bilge drains

Question 42

Which of the following is NOT listed as an anti-corrosion measure around lavatories and galleys? A) Applying Corrosion Preventative Fluids B) Increasing cabin air pressure C) Sealing floor panels

Answer 42

B) Increasing cabin air pressure

Question 43

What should be done if liquid is seen exiting from lower bilge drains? A) Apply more sealant B) Perform a routine engine check C) Investigate the source immediately

Answer 43

C) Investigate the source immediately

Question 44

What kind of environment is required when applying Corrosion Preventative Fluid (CPF)? A) Completely sealed and enclosed B) High humidity C) Well-ventilated with face mask use

Answer 44

C) Well-ventilated with face mask use

Question 45

What does CPF do when applied to aluminium surfaces? A) Increases electrical conductivity B) Attracts moisture to the surface C) Displaces water and adheres to the surface

Answer 45

C) Displaces water and adheres to the surface

Question 46

Before applying CPF, what document should be consulted? A) Maintenance Schedule Card B) Aircraft Maintenance Manual (AMM) C) Flight Operations Manual

Answer 46

B) Aircraft Maintenance Manual (AMM)

Question 47

What is the pre-mix liquid that is added to a clean waste tank A) Water and a disinfectant chemical B) Distilled water and bleach C) Water and acetic acid

Answer 47

A) Water and a disinfectant chemical

Question 48

What is the name of the water displacing fluid that adhered to the surface of clean aluminium and its alloys? A) Corrosion perservative liquid (CPL) B) Corrosion preventative liquid (CPF) C) Clean preventative water (CPW)

Answer 48

B) Corrosion preventative liquid (CPF)