Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

B747 > Air Conditioning > Flashcards

Air Conditioning Flashcards

(99 cards)

Start Studying
1
Q

There are 3 packs, what are they and where do they normally receive bleed air from?

A

Pack 1: Left pneumatic manifold
Pack 2: Center manifold
Pack 3: Right manifold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many packs can the APU supply bleed air to? Ground and in-flight?

A

3 on the ground, 1 in flight up to 15000ft*
APU can not be started in flight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many air zones are on the 747F

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Pack Control Selector: what does it do?

A

Off:
closes the associated pack valve
resets pack fault protection system
extinguishes the sys fault light
displays EICAS memo message pack 1,2 or 3 OFF
—-
NORM
normal ops automatically alternate between pack temperature and controllers A and B
—
A: selects PTC A
—
B: Selects PTC B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Pack values are Blank controlled and Blank operated?

A

Electrically and pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

If a pack is in HI FLOW how much will that increase the fuel consumption?

A

.3 % per pack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

If Both PTC A and B fail what happens to the air conditioning packs?

A

They operate in backup mode and pack overheat protection system continues to operate normally. A pack overheat results in a shutdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does it do?: Pack RST switch

A

Resets pack fault protection system
restarts pack after automatic shutdown if fault no longer exists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pack system FAULT Light

A

pack overheat or other system fault has occurred
may illuminate briefly when automatically or manually switching from pack temperature controller A to B or B to A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does it do?: FLT Deck fan switch

A

On - with all packs off, recirculated cabin air supplied to flight deck
with at least one pack on, fan increases flow of conditioned air supplied to the flight deck, fan disabled in flight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

FLT deck temperature selector

A

AUTO: auto control of flight deck temp, range from 65-85F 18-29C, in back up mode, range from C to W is set for the flight deck temp, cabin panel control is inhibited and automatic control of main deck zone temp is inhibited.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does it do?: zone RST switch

A

resets zone temp controller if fault no longer exists
reopens master trim air valve if duct overheat no longer exists
reopens forward or aft lower lobe cargo trim air shut off valve if duct overheat no longer exists.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Zone system Fault Light

A

Illuminated (amber)
-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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Main Deck temp selectors

A

auto: provides automatic control of main deck conditioned air temp
range c to w sets temp from 40C to 85C, in back up mode auto control of main deck temp is inhibited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does it do?: Forward lower lobe temp selector

A

auto:
provides automatic control of forward lower lobe cargo conditioned air temperature when lower lobe cargo conditioned air flow rate selector in FWD HIGH, BOTH LOW and FWD LOW, range from 40-85c
Man: same as auto except its manual, resets forward lower lobe cargo conditioned air supply duct shutoff valve if valve closed by duct overheat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does it do?: After lower lobe temp selector

A

Auto:
provides automatic control of aft lower lobe cargo conditioned air temperature when lower lobe cargo conditioned air flow rate selector in AFT HIGH, BOTH LOW and AFT LOW, range from 40-85c
Man: same as auto except its manual, resets after lower lobe cargo conditioned air supply duct shutoff valve is valve closed by duct overheat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does it do?: Trim Air switch

A

On:
automatic and manual selection of pack controller A or controller B enabled
mater trim air valve open and flight deck, upper deck, and main deck zone trim air valves operate automatically.
Off:
-master trim air valved closed
-pack output temperature in backup mode regulated to provide average flight deck temp from 65 to 85 as selected by flight deck temp selector in auto
-cabin temp panel control of 400f crew rest and upper deck zone temp inhibited
-pack controller A selected and both automatic and manual selection of controller b inhibited
-if pack controller A failed, pack controller b selected automatically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does it do?: Equipment cooling selector

A

STBY:
ground exhaust valve closed
automatic control bypassed to configure system for flight: inboard exhaust valve open
with a single internal fault, equipment in board exhaust valve closes and cooling system reconfigures to allow internal closed loop recirculation of cooling air.

Norm:
Ground operation based on ambient temperature, position of lower lobe conditioned air flow rate selector and temp selected by the forward lower lobe cargo temp selector; equipment cooling air exhausted overboard or exhausted into forward cargo compartment.

2 or more engines running, lower lobe cargo conditioned air flow rate selector in OFF, AFT LOW, or aft HIGH, cooling air exhausted into forward cargo compartment and ground exhaust valve closed.

2 or more engines running, lower lobe cargo conditioned air flow rate selector in fwd low, both low or fwd high and forward lower lobe cargo temperature selected less tha 50, inboard exhaust valved closed and equipment colling air recirculated in a closed loop mode.

with a single internal fault equipment inboard exhaust valve closes and cooling system reconfigures to allow internal closed loop recirculation

OVRD:
inboard exhaust valve closed
ground exhaust valve closed
equipment supply valve closed: cooling air supplied through flight panels
smo0ke/override valve open; differential pressure exhaust cooling air overboard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does it do?: Pack High Flow switch

A

on:
all operating packs configured to high flow
EICAS memo message PACKs high flow display
off:
LLCCAFR in high or both low - no effect on pack flow rates, all packs remain in high floow
LLCCAFR in fwd low, packs one and two controlled automatically, pack three remains in high flow
LLCCAFR in aft low - packs one and three controlled automatically. pack two remains in high flow
LLCCAFR in off - pack air flow controlled automatically.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does it do?: AFT cargo Heat switch

A

On;
overheat shutoff valve opens to provide bleed air heat ot aft and bulk cargo compartments
temperature control valve closes and opens to maintain temperature
overheat shutoff valve closes and opens for overheat protection

Off;
shuts off aft cargo heat bleed air to compartment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

AFT cargo temp light

A

illuminated amber;
compartment temperature excessive
overheat shutoff valve closes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does it do?: Crew rest reset switch

A

Push:
opens and resets crew rest air supply valves if valves were closed by crew rest smoke detection system and smoke is no longer detected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the LLCCAFR

A

low lobe cargo conditioned air flow rate selector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does it do?: LLWWAFR selector

A

Off:
-Forward and aft lower lobe cargo air conditioning off
-resets lower lobe cargo conditioned air supply duct shutoff valves if valves closed by duct overheat.

FWD LOW: 2/3rds of pack three conditioned air disturbed to forward lower lobe cargo compartment.

AFT LOW: 2/3rds of pack two conditioned air disturbed to after lower lobe carbo compartment

BOTH LOW: 2/3rd of pack three and pack two conditioned air distributed to respectively to forward and aft lower lobe cargo compartments

FWD HIGH: All pack three conditioned air distributed to forwaed lower lobe cargo compartment

AFT High - all pack two conditioned air distributed to aft lower lobe cargo compartment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what does it do?: Landing Altitude switch
Push: alternately changes landing altitude control between automatic and manual manual landing altitude set by rotating landing altitude selector landing altitude followed by MAN displayed on primary EICAS the EICAS advisory message LANDING ALITUDE is displayed Automatic: landing altitude set auto from FMC landing altitude followed by auto displayed on primary EICAS
26
Outflow valve manual switch
ON: outflow valve is controlled manually bypasses automatic outflow valve control and cabin altitude limiter OFF: outflow valve controlled automatically bypasses automatic out
27
Cabin Altitude AUTO selector
NORM: Cabin altitude controller A or B selected automatically on alternate flights selected controller is the primary controller; selects secondary controller if primary controller fails A - selects cabin altitde controller A as primary controller, selects B if A fails B - selects cabin altitude controller B as primary controller, selects A if B fails
28
isolation valve light
Amber: isolation valve position disagrees with switch position
29
isolation valve switches
ON; valve open off: valve closed
30
APU Bleed Air switch
On - valve commanded open when EICAS memo message APU running displayed Off- valve closed
31
Engine bleed AIR system (SYS) FAult lights
amber: bleed air overheat bleed air overpressure or HP Bleed valve open when commanded closed or PRV open when commanded closed
32
Engine Bleed Air Switches
ON: Engine bleed air valve opens for engine start engine bleed air valve, PRV and HP bleed valve open by system logic when bleed air pressure available. OFF engine bleed air valve, PRV and HP bleed valve closed PRV opens when nacelle anti-ice on, unless PRV closed by: prior or present bleed air overheat, or start valve not closed or hp bleed valve failed open
33
engine bleed air off lights
amber: engine bled air valve closed
34
APU Bleed air valve light
APU Bleed air isolation valve position disagrees with switch position
35
When are Duct pressure, cabin altitude, rate, landing altitude, and differential pressure are displayed ?
Landing altitude man cabin altitude in caution or warning range cabin differential pressure in caution or warning range ECS or ENG synoptic selected on secondary EICAS display
36
Bleed air duct pressure amb/white values
white = 12 psi and above amber 11 psi or less
37
When is a TT (target temperature) displayed for a zone temp main deck and above?
at least one pack operating and passenger temp selector in auto and temperature control is not in backup mode
38
When is a TT (target temperature) displayed for a zone temp lower lobe?
FWD: displaced when LLCCAFR selector is FWD low, FWD high, both AFT: Displayed when LLCCAFR selector is aft low, aft high or both
39
when is external air shown on the synoptic?
displayed if a pack is operating with APU and engines off, or bleed air ducts are pressurized with APU and engines off
40
What controls the packs?
two identical pack temp controllers (PTC) A and B.
41
how many channels does a PTC have to a pack?
3 channels 1 for each pack
42
What happens when a cargo fire arm switch is pushed?
Pack operation and air distribution is configured to starve the affected zone of fresh air, minimize air movement, purge smoke from the flight deck and passenger cabin, assure supply of fresh air to the flight deck
43
what happens when a pack overheats or PTC fault is detected?
the respective pack valve closes resulting in a pack shut down
44
pack flow rate is configured by?
the position of the LLCCAFR selector, phase of flight and number of operating air conditioning pack -- in the event of pack shut down or failure the system reconfigures
45
Where does the forward lower lobe cargo conditioned air supplied from?
pack three
46
how is the volume of conditioned air supplied to the forward lower lobe carrgo?
LLCCAFR
47
with the LLCCAFR selector in FWD HI
all pack three air is distributed to the forward lower lobe cargo all packs remain in high flow during cruise
48
with LLCCAFR selection in FWD LOW
2/3rds of pack three air is distributed to the forward lower lobe cargo compartment and one third is distributed to the cabin pack 3 remains in high flow during cruise
49
with the LLCCAFR in both low
2/3rds of pack three air is distributed to the forward lower lobe cargo compartment and one third to the cabin all pack remain in high flow during cruise
50
with the LLCCAFR selector in OFF or AFT what happens to the forward lower lobe cargo compartment? what happens to that air?
conditioned air to the forward lower lobe cargo compartment is shut off all pack three air is distributed to the cabin the cargo exhaust system discharges the air to prevent odors from migrating into the cabin. the flight exhaust system discharges the air overboard through the overboard valve on the fuselage side skin
51
Where does the aft lower lobe cargo compartment get its air?
Pack 2
52
what controls the volume of air to the after lower lobe cargo compartment??
LLCCAFR selector
53
with the LLCCAFR selector in aft hi what happens?
all pack two air is distributed to aft lower lobe cargo all packs Remian in high flow during cruise
54
with the LLCCAFR selector in aft low what happens
pack two air is distributed to both aft lower lobe cargo and the cabin pack two remains in high flow during cruise
54
with the LLCCAFR selector in OFF or FWD what happens to the aft lower lobe cargo compartment? what happens to that air?
conditioned air to the aft lower lobe cargo compartment is shut off, all pack 2 air is distrusted to the cabin
54
with the LLCCAFR selector in both low what happens
pack two air is distributed to both after lower lobe cargo and the cabin all packs remain in high flow during cruise
55
zone temps are controlled how?
zone temp controllers
56
with the LLCCAFR selector in off what zone controlls pack outlet temp?
the zone requiring the coolest temperature
57
If the LLCCAFR selector is in FWD HI what happens to the pack outlet temps
pack 3 outlet temp is controlled to maintain forward lower lobe temp. the coolest of flight deck/upper deck/crew rest/ main deck requested temps control pack outlet temp for pack 1 and 2.
58
If the LLCCAFR selector is in AFT HI what happens to the pack outlet temps
pack 2 outlet temp is controlled to maintain aft lower lobe cargo compartment commanded temperature. the coolest of flight deck/upper deck/crew rest/ main deck requested temps control pack outlet temp for pack 1 and 3.
59
if the LLCCAFR selector is in low what does the ZTC do regarding pack outlet temperature?
it limits pack outlet temperature of the pack supplying the selected lower lobe cargo compartment to be not higher than the pack outlet temp of the other two packs. the ZTC regulates the temp of the selected lower lobe cargo compartment by; closing the trim modulating valve and supplying cooler air from the pack supplying conditioned air to the compartment or modulating the cargo trim air valve to supply warmer conditioned air.
60
When is trim air not available to the flight deck upper deck crew rest main deck?
TEMP ZONE displayed on EICAS the center section of the bleed duct is isolated TRIM AIR OFF is displayed or MASTER Trim Air Switch is OFF
61
What happens if to the flight deck / upper deck / crew rest / main deck if trim air is not available?
if the flight deck temp selector setting is avilable to ptc, pack outlet temp of all packs is regulated to achieve an average between 65-85F. or if flight deck temp selector setting is unavailable to the PTC, pack outlet temp is regulated to achieve the last flight deck temp set or if the last flight temp is unavailable to the PTC, pack outlet temp is regulated to 75
62
when is trim air not available to the aft lower lobe cargo?
center section of the bleed duct is isolated or EICAS temp zone due to lower aft zone duct overheat or for ztc fault that causes that aft forward to trim air valve to close
62
when is trim air not available to the forward lower lobe cargo?
center section of the bleed duct is isolated or EICAS temp zone due to lower forward zone duct overheat or for ztc fault that causes that lower forward to trim air valve to close
63
if trim air is not available to the lower forward or aft how does the back up mode control temperature?
if the forward or aft lower temp setting is available to the PTV pack 3 (pack 2 for aft) is regulated to the achieve the temperature set by the selector or if the forward or aft lower temp setting is not aviable to the PTC, pack 3 (pack 2 for aft) is regulated to achieve the cargo temp sensed at the time backup mode was initiated or if forward or aft lower lobe cargo temp is unavailable to the PTC, pack 3 (pack 2 if aft) is controlled to the pack outlet temp senses at the time back up mode was intiated.
64
if a system fault or overheat occurs in the flight deck, upper deck, crew rest, or main deck, what happens to the trim air?
master trim air closes and backup ,mode controls cabin temp
65
if a system fault or overheat occurs in lower cargo what happens?
cargo zone trim air shutoff valve closes and a back up mode controls temperature.
66
how would you reset the cargo air trim shutoff valve?
position the cargo temp selector from auto to man or from man to auto, positioning LLCCAFR selctor to off does the same thing.
67
What heats the forward Cargo?
exhaust from the E/E
68
what heats the aft cargo?
bleed air from the center section of the bleed air duct. a thermal switch in the compartment opens and closes the temp control valve. an overheat thermal switch provides overheat protection
69
What are 3 possibilities for the E/E exhaust air?
Forward cargo, closed loop (cool temps), overboard (hot temps)
69
When does the E/E configure for flight?
no engines running on the ground when its cold. 1 or more engines on the ground running. position the selector to stby
69
What is flight configuration for E/E (freighter)
dependent on the LLCCAFR selector and forward LLcargo temp selector; colder than 50 degrees LLCCAFR in FWD low/high or both low, inboard exhuast valve is closed, goes to closed loop. warmer than 50 and the inboard exhaust valve is open
70
when is conditioned air from the packs directed into te lfight deck electrical equipment?
when two or 3 packs operating
71
how is cabin pressurization controlled?
2 outflow valves located near the rear of the cabin, they operate in Parrell
72
how many cabin altitude controllers?
2, A and B, each controller controls both outflow valves
73
what protects the aircraft against excessive pressure differential?
positive and negative relief vales
74
how do the cabin altitude controllers calculate a pressurization schedule?
FMC flight plan data and ambient pressure
75
how many positive pressure relief valves are there?
two mechanical prevent over pressurization
76
if cruise altitude is unavailable from the FMC in AUTO what does the cabin altitude controller assume for ALT?
FL390
77
where are the negative pressure relief valves located?
side cargo door
78
In the event of over pressurization what happens?
pThe positive pressure relief valves open and pack 2 will shuts down to assist in relieving excess pressure
79
where is engine bleed air supplied from?
from either the IP or HP engine sections. IP section during high power settings, HP for lower power settings.
80
What limits bleed air pressure?
the PRV
81
What regulates bleed air temperature?
fan air Precooler
82
when does a engine bleed air valve close?
when a ground cart is supply air if a bleed air over temperature occurs if a bleed air over pressure occurs if a bleed source loss occurs if a blee air duct leak occurs when an engine fire switch is pulled
83
if the engine start valve fails to close what happens?
the respective engine nacelle anti ice is not available
84
what happens if the engine bleed air switch is off?
the respective engine bleed air valve and prv and HO bleed valved are closed/
85
if a bleed air overheat is detected what happens?
the PRV and and HP blled vavles close.
86
bleed air is available for nacelle anti ice operation with the engine bleed air switch on except when?
start valve is not closed PRV has failed closed PRV has been closed due to a bleed air overheat
87
bleed air is not available for nacelle anti ice operation with the engine bleed air switch off except when?
start valve is not closed PRV has failed closed PRV has been closed due to a bleed air overheat the HP bleed valve is failed open
88
bleed air is available for thrust reverser operation with the engine bleed air switch either on or off except when
prv has failed closed or prv has been closed due a bleed air overheat or start valve is not closed.
89
where is apu bleed air supplied to?
the center section of the bleed air dct.
90
what prevents reverse flow of bleed air to the apu?
a check valve
91
if the apu shuts down for an overheat can it be restarted?
no
92
how is a duct leak or overheat detected?>
by the bleed duct overheat system, if detected it can be isolated by closing the respective isolation and engine bleed air valves.
93
if the center duct is isolated, what does pushing the AFT cargo heat switch off do?
closes the electrically operated aft cargo heat valves to prevent cabin air flowing in reverse through the aft cargo heat supply duct and into the leaking center duct. all temp zones operate in back up mode since trim air wouldn't be available. potatable water pressurization and cargo smoke detection are not available.
93
if the left or right duct is isolated what happens?
the respective leading-edge flaps operate in secondary mode

B747 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions