11.17 Water & Waste

Question 1

What are the 3 subsystems of a water & waste system?

Answer 1

potable water system, toilet system, water waste system

Question 2

Where is potable water stored?

Answer 2

below the cabin floor in the cargo area sidewalls

Question 3

What is potable water used for?

Answer 3

galley & lavatory components

Question 4

What can be used to pressurize the potable water system?

Answer 4

a water tank pressurization system, or an electric pump

Question 5

What is the most common air filter used in a water tank pressurization system?

Answer 5

replaceable 10-micron filtration cellulose element

Question 6

What is the function of an air filter?

Answer 6

prevent contamination & dirt, from the air supply, entering the portable water system

Question 7

What is the function of the check valves?

Answer 7

prevent reverse pressurization to air supply when its pressure is lower than the water tank pressure

Question 8

Where is the PRV located?

Answer 8

between the pressure switch & water storage tanks

Question 9

When must you completely drain the water system?

Answer 9

before disinfecting the system, when parking in freezing weather, every 3 days to prevent bacteria growth

Question 10

Which 2 places can you service the portable water system from?

Answer 10

water service panel & water drain panel

Question 11

Where is the water service panel located & why is it located there?

Answer 11

in a recess on the lower part of the fuselage, covered by an access door - wont interfere with other servicing activities during turn-arounds

Question 12

What are the 2 ways a faucet assembly is controlled?

Answer 12

mechanically or infrared

Question 13

How is an infrared faucet controlled?

Answer 13

by a reflective sensor unit with 2 lenses

Question 14

What happens when water is required in an infrared system?

Answer 14

the reflective sensor unit opens a solenoid-operated SOV on the mixer valve

Question 15

What is the purpose of a water heater?

Answer 15

provides hot water to the washbasin in each lavatory

Question 16

How much water can a heater tank hold?

Answer 16

1.5litres

Question 17

What is the function of a waste water system?

Answer 17

removes used water from washbasins in lavatory & galley areas & drains it out the aircraft through drains & drain masts

Question 18

What makes the wastewater flow?

Answer 18

gravity

Question 19

What prevents water freezing in drain masts & wastewater lines?

Answer 19

they are electically-heated

Question 20

What is wastewater also known as?

Answer 20

grey water

Question 21

What is not classified as greywater & what is greywater used for?

Answer 21

toilet waste - assist toilet flushing

Question 22

What are the 2 types of toilet waste systems?

Answer 22

flush motor toilets & vacuum toilet systems

Question 23

What does a separator do & where is it located in a flush motor toilet?

Answer 23

prevents splash & vision of tank contents - between tank & bowl

Question 24

How long is the flush time on a flush motor toilet?

Answer 24

8-12secs

Question 25

What is the motor described as in a flush motor toilet & what is it controlled by?

Answer 25

high power 3-phase electric motor - timer

Question 26

What type of pump does a flush motor toilet system contain?

Answer 26

impeller

Question 27

What is the liquid in a flush motor toilet waste tank a mixture of?

Answer 27

water & a chemical

Question 28

How many times can flush motor toilets be used & what must happen after this is exceeded?

Answer 28

100 times - tank must be drained from an external service panel

Question 29

How is a vacuum toilet system controlled?

Answer 29

electronically by a FCU (Flush Control Unit)

Question 30

How many central waste tanks does a vacuum waste system have & where are they located?

Answer 30

2 or more - cargo compartment

Question 31

When is blue ice phenomenon formed in a vacuum toilet system & what is the associated danger?

Answer 31

if there is a leak at the waste drain valve assembly whilst aircraft is flying at altitude - blue ice formed can cause damage on ground

Question 32

How much chemical solution can the flush motor toilet system tank be charged with during servicing & what is used to do this?

Answer 32

13-31litres - connect chemical line from service cart to ground flush line fitting

Question 33

What is CPF (Corrosion Preventative Fluid)?

Answer 33

water-displacing fluid that adheres to the surface of clean/primed aluminum & its alloys