ECS Air Con

Question 1

What happens to the outflow valves upon touchdown?

Answer 1

they go full open

Question 2

If one outflow valve is in manual, will the other outflow valve operate in auto?

Answer 2

yes

Question 3

Where/When can I observe cabin altitude and rate, landing altitude, and differential pressure?

Answer 3

Primary EICAS when:- landing altitude in manual- cabin altitude in caution or warning - cabin differential pressure in caution or warning - ECS or ENG selected on lower EICAS

Question 4

Is there auto switching of cabin altitude controllers if one should fail?

Answer 4

yes

Question 5

When does the cabin altitude waring siren sound?

Answer 5

excessive cabin altitude (greater than 10,000 ft)

Question 6

What is the max allowable cabin differential pressure for takeoff and landing?

Answer 6

0.11 PSI

Question 7

What is the max differential pressure?

Answer 7

9.4 PSI

Question 8

How many positive pressure relief valves are there nd where are they located?

Answer 8

2 in E&E compartment (left front compartment)

Question 9

Where are the negative pressure relief valves located?

Answer 9

side cargo door and forward and aft cargo doors

Question 10

What is the temp range for the flight deck?

Answer 10

18C-29C

Question 11

What does the manual position of the temperature controllers do?

Answer 11

sets the trim air valves manually

Question 12

What will cause a zone system fault light to illuminate?

Answer 12

NAME?

Question 13

What will cause a pack system fault light to illuminate?

Answer 13

NAME?

Question 14

What happens when you press the trim air switch to off?

Answer 14

NAME?

Question 15

On the ground, engines not running, where is Equip. Cooling exhaust air routed?

Answer 15

• into the lower forward cargo compartment when temp < 7C- ducted overboard when temp > 7C

Question 16

What happens to the Equip. Cooling system on the ground when engines are running?

Answer 16

configures for flight, closing the outboard exhaust valve, venting the air into the lower FWD cargo compartment

Question 17

What does the STBY position of the Equip. Cooling system do?

Answer 17

manually configures the aircraft for flight

Question 18

What does the OVRD position of the Equip. Cooling system do?

Answer 18

the fans are deactivated and the air is vented overboard using cabin differential pressure

Question 19

What position is the APU bleed air switch normally in?ENgine bleed air switches?

Answer 19

On- air con logic automatically opens and closes the valveOn- will indícate closed if other bleed sources are powering AC (APU or ground air)Also will show off until pressure is available to open the valve.

Question 20

Which section does bleed air normally come from?

Answer 20

IP - Intermediate section

Question 21

During start what do the bleed valve AND PRV valves do on the starting engine?

Answer 21

When you pull the start switch on the overhead:The Bleed valve opens to allow air to pass through the start valve to get to the engine to turn it.The PRV VALVE closes to prevent flow into the compressor sectionWhen you put the FUEL CONTROL SWITCH on the CENTER pedestal to RUN that opens the START VALVE turning the engine.At 50%N2 the start valve closes again, the PRV valve then opens allowing the engine to supply bleeds to the packs once again.

Question 22

Do the lower cargo lines receive air conditioned by trim air?

Answer 22

No, it’s straight from the bleed air ductThus if the master trim air valve is closed it does not affect the lower cargo heat.

Question 23

What is meant by the master trim valve?

Answer 23

It is the valve that allows the hot bleed air to flow to 3 other trim air modulating valves that supply the different zones.The modulating valve that serves the coldest zone remains closed to allow maximum cooling.

Question 24

What is the temp range for cargo and main deck?

Answer 24

4-29C

Question 25

Which packs supply air directly to the fwd and aft cargo?

Answer 25

Fwd- pack 3Aft - pack 2In LOW positions the associated pack provide 2/3 flow to cargo and 1/3 to ac manifoldOFF- they provide no air to the cargo. 100% to the AC manifold.HIGH - all of the associated pack conditions the assoc cargo compartment.Basically OFF and HIGH are opposites. One or the other manifold or cargo

Question 26

On the ground, before having at least two engines started where does the equipment cooling air exhaust to?After the second engine is started where does the air go?

Answer 26

Before the second engine is started it exhausts into the fwd cargo. If the temp is high then it flows outside through the GROUND EXHAUST VALVE.After the second engine start, the GROUND EXHAUST VALVE closes. You can force this by turning the equip cooling switch to STANDBY

Question 27

If in NORM OR STBY modes for equip cooling and 1 supply fan fails, what does the system automatically do?

Answer 27

Goes into a closed loop mode by closing the GROUND EXHAUST VALVE, INBOARD SUPPLY VALVE and the INBOARD EXHAUST VALVE.(Basically shuts off incoming and outgoing air)

Question 28

Explain how the aft cargo heat works?

Answer 28

When you turn the switch on it opens two valves: TEMP CONTR VALVE AND OVERHEAT SHUTOFF VALVE. These allow air to flow into the compartment from pack 2.The heat control is in the cargo compartment (HI/LO)If using the LLCAFR switch it will close the TEMP CONTROL VALVE. However if the temp in the floor of the aft cargo that valve reopens heating the compartment.