Air conditioning ***

Question 1

What is the flight deck temperature range with the Flight Deck (FLT) temperature Selector in AUTO?

Answer 1

• 18C to 29C

Question 2

What valve are you controlling when you select MAN with the flight deck temperature controller?

Answer 2

• Flight deck trim air valve

Question 3

What does the Zone System (SYS) Fault Light indicate?

Answer 3

• Temperature zone duct overheat or
• Zone temperature controller fault has occurred.
• Master trim air valve failed closed
• Trim air switch off
• Master trim air valve closed and pack air continues to flow.

Question 4

What is the temperature range with the main deck and forward and aft lobe temperature selectors in AUTO?

Answer 4

• 4C to 29C

Question 5

Under what conditions would trim air be unavailable to the flight deck, upper deck, crew rest, and main deck?

Answer 5

• EICAS advisory TEMP ZONE is displayed.
• Center section of the bleed duct is isolated.
• EICAS Advisory message TRIM AIR OFF is displayed.
• The Master Trim Air switch is OFF.

Question 6

If trim air is not available to the flight deck, upper deck, crew rest, and Main deck distribution system, how is temperature controlled in the cabin?

Answer 6

• Operate in Backup modes control temperature

• If the flight deck temp selector setting is available to the PTC, pack outlet
temperature of all packs is regulated to an average temp between 18C and 29C, as set by the Flt Deck Temp selector, or

• If unavailable to the PTC, the last temperature set, or
• If last temp unavailable to the PTC, then 24C

Question 7

What target temperature is set to the upper deck and crew rest zone when electrical power is initially applied to the airplane?

Answer 7

• 24C

Question 8

How many pack temperature controllers (PTC) are provided?

Answer 8

• Two – A and B

Question 9

How many separate channels are provided in the PTCs?

Answer 9

• Each PTC has three separate channels, one for each pack.

Question 10

What happens if a pack temperature controller (PTC) detects a fault in a pack channel?

Answer 10

• Control of the respective pack switches to the other PTC.

Question 11

How can you restore pack operation for a failed PTC?

Answer 11

• Push the Pack Reset Switch.

Question 12

What would happen if a fault or an overheat of the PTC is detected?

Answer 12

• The respective pack valve closes, resulting in a pack shutdown.

Question 13

What are the 7 temperature zones for the 400F?

Answer 13

• Flight deck/upper deck/crew rest
• Forward and aft main deck
• Forward and aft lower lobe cargo zones

Question 14

What is the function of the Lower Lobe Cargo Conditioned AIR FLOW RATE Selector? (LLCCAFR)

Answer 14

• Provides forward and aft lobe cargo air conditioning.

Question 15

With the LLCCAFR Switch Off, what controls pack outlet temperature?

Answer 15

• The flight deck, upper deck, and crew rest zone requiring the coolest temperature.

Question 16

What zone and what pack is affected with the LLCCAFR selector in FWD HI?

Answer 16

• All of pack three air is sent to the forward lower cargo lobe.

Question 17

What zone and what pack is affected with the LLCCAFR selector in AFT HI?

Answer 17

• All of pack two air is sent to the aft lower cargo lobe.

Question 18

Explain the position of the LLCCAFR selector in BOTH LOW.

Answer 18

• 2/3 of pack 3 and 2/3 of pack 2 conditioned air distributed respectively to
forward and aft lower lobe cargo compartments.

Question 19

What Position of the LLCCAFR selector would result in all packs remaining in High flow during Cruise

Answer 19

FWD HI/AFT HI

BOTH LOW

Question 20

describe overheat protection of the cargo heat system

Answer 20

an overheat thermal switch provide overheat protection by opening and closing an overheat / shutoff valve at higher temperature

Question 21

What is the source of heat for the forward cargo compartment?

Answer 21

when the cooling system inboard exhaust valve is open the heated air exhaust from electrical and electronic (E&E) compartment heats the Forward cargo compartment

Question 22

What is the source of heat for the AFT cargo compartment?

Answer 22

Aft cargo heat is provided by bleed air from the center section of the bleed air duct.

Question 23

Explain the position of the LLCCAFR with the selector in the following positions:

FWD LOW
AFT LOW
BOTH LOW

Answer 23

1- 2/3 of pack 3 to FWD lower lobe
2- 2/3 of pack 2 to AFT lower lobe
3- 2/3 of pack 3 to FWD lower lobe and 2/3 of pack 2 to AFT lower lobe

Question 24

What zone and what pack is affected with the LLCCAFR selector in the following positions:

FWD HI?
AFT HI?

Answer 24

1- All of pack 3 air is sent to foward lower cargo lobe

2- All of pack 2 air is sent to the aft lower cargo lobe

Question 25

What provides equipment cooling with the equipment cooling selector in override?

Answer 25

Differential pressurized air is drawn over equipment and vented overboard through the Smoke/Override valve.

Question 26

With the loss of trim air, what happens in the air conditioning pressurization
system?

Answer 26

Backup modes control temperature in the cabin, depending on the position of the flight deck temperature selector.

If flight deck temp selector setting is available to PTC will
regulate to achieve an average temp between 18C and 29C.

If flight deck temp selector not available to PTC regulated to achieve last flight deck temp set or

if flight deck temp set is unavailable to PTC will regulate to flight deck temp of 24C

Question 27

How is the forward cargo compartment heated?

Answer 27

This depends on the position of the LLCCAFR switch and temp selected.

If the LLCCAFR switch is in FWD LOW, BOTH LOW or FWD HIGH and the temp selected is lower than 10C the inboard exhaust valve is closed and equipment cooling is recirculated in a closed loop mode.

With higher selected temp or all other positions of
the LLCCAFC, the inboard exhaust valve is open and the warm equipment cooling air discharges into the forward cargo compartment

Question 28

The master trim air switch controls the temperature to which zones

Answer 28

5 zones

Flight deck
Upper deck
Crew Rest
Fwd Main Deck
Aft Main Deck