Air Management System

Question 1

What are the 4 things that the engine/APU bleed air can provide for?

Answer 1

Anti Ice (Engine bleed air Only)

Water Pressurization

PACKS/ECS (APU can up to 15,000ft)

Engine Start

Question 2

Where does the bleed air come from?

Answer 2

Engines and APU

Question 3

Takeoff ECS ON or ECS OFF differences

Answer 3

ECS ON = Engine providing bleed air for ECS

ECS ECS OFF = APU providing bleed air for ECS

Question 4

Purpose and function of the Air Recirculation Fans? When will AUTO shut down?

Answer 4

Recycles the cabin air and will turn on automatically when one PACK comes on

Will automatically turn off if both PACKs are off and when smoke is detected in the cargo or recirculation bay

Question 5

Total flow and consistency of recirculation fans?

Answer 5

52% fresh air and 48% recycled

Question 6

Components of pressurization system

Answer 6

• 2 CPCs - Cabin Pressure Controllers. Regulators that control the cabin pressure.
• OFV - Outflow Valve. Modulates airflow and controls pressurization
• NPRV - Negative Pressure Relief Valve. Automatically opens and keeps the max differential pressure above -0.5psi
• Safety Valve - Positive Pressure Relief Valve. Automatically opens if cabin differential pressure exceeds 8.6 PSI. Keeps the max differential pressure below 8.8psi Spring loaded/mechanical (requires no power)
• Static Port - a heated port that sends information to the Safety Valve to keep plane within

Question 7

OFV

Answer 7

Outflow Valve. Modulates airflow and controls pressurization

Question 8

NPRV

Answer 8

Negative Pressure Relief Valve. Automatically opens and keeps the max differential pressure above-0.5psi

Question 9

Safety Valve

Answer 9

Positive Pressure Relief Valve. Automatically opens if cabin differential pressure exceeds 8.6 PSI. Keeps the max differential pressure below 8.8psi Spring loaded/mechanical (requires no power)

Question 10

Static Port-

Answer 10

a heated port that sends information to the Safety Valve to keep plane within tolerances

Question 11

Where is the Ram Air Valve and what is the purpose?

Answer 11

Underneath on the belly of the aircraft Provides emergency ventilation in case of PACK shutdown or smoke removal The Ram Air Valves are automatically commanded OPEN if both PACKs are OFF below 25,000ft Includes a check valve that only allows ram air into the cabin when ram air pressure > cabin air pressure

Question 12

What is a PACK?

Answer 12

Pneumatic Air Conditioning Kit that provides cabin heating, A/C, and pressurization from the same side engine. There is a Xfeed for the PACKs bleed air if engine or pack fails however aircraft is limited to FL310

Question 13

When will the PACK come on and off in AUTO?

Answer 13

Will come on when engine or APU bleed air is available

Will turn off during engine start or an associated bleed duct leak is suspected (amber light on button)

Question 14

When will the XBleed come on and off in AUTO?

Answer 14

Will come on when bleed air is available on one side but not the other

Will turn off bleed leak is detected (unless starting an engine) or when the engine fire extinguisher handle is pulled

Question 15

What are the external air connections?

Answer 15

High Pressure for engine starting (Huffer Cart) and is used when APU is INOP. IS shown on ECS synoptic page Low Pressure for cabin heating and cooling (used at most airports). IS NOT shown in cockpit

Question 16

When will Engine Bleed come on and off in AUTO?

Answer 16

Will come on when respective engine bleed is available

Will turn off if fire is detected in respective engine or there is a bleed duct leak or overpressure detected

Question 17

When will APU Bleed come on and off in AUTO?

Answer 17

Will come on when APU bleed is available
Will turn off:
if bleed duct leak is detected
A/I comes on or
left engine bleed is available

Question 18

What does MAN do in the pressurization panel mode selector

Answer 18

Manual control of OFV. Moving Down closes the outflow valve pumping more air in. Moving Up opens outflow valve letting air flow out

Question 19

What does AUTO do in the pressurization panel mode selector

Answer 19

Generates a pressurization schedule based on the departure, cruise, and destination heights set in the FMS

Question 20

What does LFE CTRL do in the pressurization panel mode selector. How do you know it is on?Is pressurization still AUTO?

Answer 20

If destination elevation is not in the FMS database we can manually set it; however the pressurization will still be automatic. Manual elevation will have a cyan M on the EICAS

Question 21

When would you use the CABIN ALT knob?

Answer 21

When the QRH says to manually take over the pressurization.

Question 22

Does the function of the CABIN ALT knob rely on a position of the MODE knob?

Answer 22

Yes, you need to be in Manual mode.

Question 23

Does the function of the LFE knob rely on the position of the MODE knob?

Answer 23

Yes, you need to be in LFE mode

Question 24

Where does the LFE altitude read out in the aircraft?

Answer 24

On the EICAS screen Cyan M

Question 25

What happens when I press the dump button with the mode selector in AUTO? LFE CTRL? MAN?

Answer 25

In Auto and LFE it will shut off the re-circ fans, shut off the PACKs, and open the outflow to allow a 2000fpm climb in cabin altitude up to 12,400.

In Manual, the re-circ and PACKs shut off only