ECS

Question 1

Need for ECS

Answer 1

Humans need protection for the effects that changes in environments cause.

Question 2

Temperature, its effect

Answer 2

Low temp- Humans cant stand low temps for long as it causes lack in judgement and motor functions. eventually will cause death

high temp-High temps cause you to sweat, if this fails you become overheated leading to fall in mental state, fatigue and unconsciousness.

Question 3

Humidity.

Answer 3

low moisture content of air causes cold sensation because dry air causes moisture to dry around the body. can be tolerated for a short time before discomfort and lack of efficiency

Question 4

Cabin environment meaning

Answer 4

methods used are designed to over come injurious effects of the outside atmosphere may cause, provide complete protection for crew and aircrew

Question 5

aspects of cabin environment

Answer 5

Temperature
humidity
Ventilation
purity
pressure

Question 6

Temperature

Answer 6

maintain suitable temp inside cabin

control release of heat from equiptment and occupants

Question 7

Humidity

Answer 7

Prevent misting by removing moisture
limit the rise in humidity above certain levels
prevents low humidity

Question 8

ventilation

Answer 8

prevent CO2 levels from getting to high

stops smells

Question 9

purity

Answer 9

stop gases from being introduced into cabin, my making air pure
removes fumes and dust that are harmfull to health and can damage systems

Question 10

pressure

Answer 10

maintain pressure to prevent the harmful effects of high pressure

Question 11

air conditioning

Answer 11

controls temp. provide air supply to satisfy ventilation and pressurisation requirements. make cockpit comfy

Question 12

engine bleed air

Answer 12

air condition uses this air from the late compressor stage of the turbine engine.

compressor bleed air is used for deicing and anti ice, cabin pressurisation, heating and cooling systems

Question 13

Auxillary power unit

Answer 13

a/c with apu can use the bleed air to condition the a/c when it its grounded.

Question 14

ground trolley

Answer 14

ground vehicle thats used to supply air. when external source is connected, internal check valves open and pressurised air come through. external air/ground receptacle allows this

Question 15

Ram air

Answer 15

intake ducts guide air into the cabin. forward movement pushes air into the air ducts causing a pressure build up

Question 16

Air condition

Answer 16

Complete system, control both temp and humidity and heating and cooling if necessary

provide adequate movement of air through vents, cabin doors should come off.

Question 17

Air cooling

Answer 17

hot compressor bleed air taken from engine , basic physics used to cool air then mix with hot bleed air to achieve desired temps.

Question 18

heat exchangers

Answer 18

radiatior that has metal fins that catch the hot bleed air, uses cold ram air to cool the bleed air

Question 19

fans

Answer 19

fans provide air flow to cool heat exchangers

Question 20

Cold air unit (CAU)

Answer 20

turbine engine extracts energy from burning fuel to turn compressor. compressed air taken from engine bleed air fed into CAU where it turn the fans inside. large amount of its energy is used for this resulting in a pressure loss, resulting in lower temps

Question 21

water extraction

Answer 21

Moisture from the CAU is fed into a fibreglass sock which catches the moisture, then slung into the sides of the container then carried overboard by the drain valve.

Question 22

Cabin temp sensor

Answer 22

use in tandem with a/c air con, thermistor with a protective sleeve used to tell the difference.

Question 23

Whats a thermistor

Answer 23

electrical resistor which resistance is reduced by heating

Question 24

temperature control.

Answer 24

located in cabin to control temp. cooled air passes through mixer then the controller uses sense difference to determine how much of the mixed air to release, two mode automatic and manual

Question 25

shut off

Answer 25

ac shutoff valve is used to control the flow of air. can either shut off the valve or modualte the flow of the air

Question 26

cabin distrobution

Answer 26

Air vents near the feat and lower body parts , controlled by the user. cold air only on vents that are opened by used.

Question 27

Ventilation

Answer 27

could be a window of little valve that deliver ram air. some fans to help airflow when a/c is grounded.

Question 28

conditioning systems

Answer 28

hot air from engine compressors routed through primary and secondary heat exchanges and cold air unit.
to provide airstream at req temp, enters mixing chamber where its mixed with recycled cabin air and hot moist bypass air. any water is removed here.

Question 29

operation of conditioning systems

Answer 29

bleed air enters primary heat exchangers and cooled by ram air before sent to on/off valve.

when off bleed air cannot flow into system
when on bleed air operates at a reduced temp and pressure to the CAU where the air is compressed again.

Question 30

what happens when air is compressed in the CAU

Answer 30

temp is raised then ducted to secondary heat exchanges where temp is reduced again before flowing into CAU turbine inlet. during passage air is expanded and temp and press reduced. finally sent through water extractor.

Question 31

what does fully cold mean.

Answer 31

fully cold- at temp control mixer will remain closed. all air is passed into cabin beofr entering both heat exchanges and CAU

Question 32

what does intermediate temperature mean

Answer 32

air flow of pre cooled air skips secondary heat exchange/CAU, mixed with air from primary heat exchange before entering the cabin.

if temp valve is increase more by pilot it allows more of this air into the cabin

Question 33

what does hot operation mean

Answer 33

Temperature control valve opened fully al hot air bypass Secondary heat exchanges and is entered into the cabin

Question 34

cabin warning indicators

Answer 34

failure of these system can cause serious affects., warning system incorporated so that crew can see if one fails. some have individual warning devices but most are at the central warning panel

Question 35

What is the sign for excessive cabing temp.

Answer 35

illumination of “Air T” on CWP, done by using a “high limit” thermostat which will remain lit until temps return to normal operating level.