Air Systems Flashcards by Aaron Mazyck

What does the Air Conditioning system use to control temperature?

The 3 packs

How well did you know this?

Not at all

Perfectly

What are the temperature zones?

Flight Deck
Upper Deck
Crew Rest
Forward and aft Main Deck
Forward and aft Lobe cargo

How well did you know this?

Not at all

Perfectly

What is the route of air from the engine to the cabin?

Engine > Packs > Distribution system> Cabin

How well did you know this?

Not at all

Perfectly

On the ground with the packs off, how can we air condition the cabin?

With LP air connected to the distribution system

How well did you know this?

Not at all

Perfectly

What can power the packs?

Engines
APU
HP ground air

How well did you know this?

Not at all

Perfectly

What is the PTC?

Pack Temperature Controller

How well did you know this?

Not at all

Perfectly

On the Temperature display what are the temperature indications?

Magenta - Target
Actual - White

How well did you know this?

Not at all

Perfectly

What is the function of the trim air system?

Can add bleed air to any zone so that each zone may be independently controlled

How well did you know this?

Not at all

Perfectly

What is the advantage of normal flow over high flow?

Improved fuel efficiency

How well did you know this?

Not at all

Perfectly

How many temperature zones are on the Freighter B747 Aircraft?

How well did you know this?

Not at all

Perfectly

T/F: As a precaution both Pack Temperature Controllers are active at the same time.

False

How well did you know this?

Not at all

Perfectly

The three identical packs are normally supplied bleed air from the __________.

Engines

How well did you know this?

Not at all

Perfectly

The master temperature for the Cabin can be adjusted between ________ and ________.

18C -29C
65F - 85F

How well did you know this?

Not at all

Perfectly

What is the route of airflow inside the pack?

Through the 2 heat exchangers, the compressor, turbine, and water separator.

How well did you know this?

Not at all

Perfectly

What happens when a pack selector is set to OFF

-Resets the pack fault protection system
-Extinguishes the SYS FAULT light (if it was illuminated due to a fault in the associated pack).
-EICAS memo message PACK 1,2, or 3 OFF displays
-OFF will also be displayed on the ECS synoptic display

How well did you know this?

Not at all

Perfectly

What will happen if a fault is detected on a PTC that a pack is using?

The associated pack will automatically switch to the other PTC, with trim air ON

How well did you know this?

Not at all

Perfectly

What will happen if a fault is detected on a PTC that a pack is using, with trim air OFF?

The associated pack will select PTC A in manual or auto and B can only be used if A fails, with trim air OFF

How well did you know this?

Not at all

Perfectly

What determines the flow rate when the HI FLOW switch is OFF?

Automatically controlled.

How well did you know this?

Not at all

Perfectly

What does it mean when the PACK RST SYS FAULT light illuminates?

a PTC fault or a pack overheat is detected, and the respective pack valve will close with the result of a pack shutdown

How well did you know this?

Not at all

Perfectly

What happens if PTC A and B fail?

The packs will operate in a backup mode

How well did you know this?

Not at all

Perfectly

If PTC A is selected and PTC A fails, does the pack automatically switch to the PTC B?

Yes

How well did you know this?

Not at all

Perfectly

T/F: Packs will only operate in HIGH FLOW Mode when the HIGH FLOW Switch is selected ON.

FALSE

How well did you know this?

Not at all

Perfectly

Fuel consumption is reduced approximately _______ for each pack in normal flow.

.3%

How well did you know this?

Not at all

Perfectly

If all packs are selected OFF, what EICAS Memo Message will display?

Packs OFF

How well did you know this?

Not at all

Perfectly

What does the Equipment Cooling System provides cool air to?

Flight Deck Electrical Equipment and for the Electrical and Electronic (E&E) compartments.

What happens to the exhaust air form the E&E compartment on the ground with the engines not operating?

May be routed overboard for warm ambient temperatures or routed to the forward cargo compartment for cold ambient temperatures. The determination of the routing of the air is based upon the ambient temperature, the position of the Lower Lobe Cargo Conditioned Air Flow Rate selector, and the temperature that is selected by the Forward Lower Lobe Cargo Temperature Selector.

When is flight configuration automatically selected for equipment cooling?

When at least 1 engine on each wing is running.

How can flight configuration be manually selected for equipment cooling?

By selecting STBY

What can a EQUIP COOLING EICAS message indicate?

-Equipment cooling airflow is inadequate -Overheat or smoke detected -Equipment cooling selector to OVRD and diff pressure for reverse flow cooling is inadequate -Ground exhaust valve not in commanded position

What is the EQUIP COOLING selector OVRD for?

Ensures equipment cooling when the internal fans are inoperative via reverse airflow

With the aircraft on the ground, no engines running, and cool ambient temperatures, what mode is the Equipment Cooling System operating in?

Flight Mode

T/F: The EICAS caution message EQUIP COOLING displays only when an overheat or smoke is detected in the Equipment Cooling System.

False

What powers the trim air in the lower lobe cargo?

Supplied directly from the bleed air duct

What determines pack flow rate?

-Phase of flight -Number of packs operating -Position of lower lobe car rate selector

What is ZTC in air conditioning?

Zone Temperature Controller

How does the ZTC maintain temperature?

By setting cold pack outlet and adding trim air to selected zones

What is the MAIN DECK TEMP selectable range?

4C to 29C

When a temp selector is in manual, what happens when selecting temperatures C or W?

C: Trim air valve closed W: Trim air valve open

Can the flight deck fan be used in flight?

No, it is disabled regardless of switch position

What is the FLT DECK TEMP selectable range?

18C -29C

What occurs with TRIM AIR OFF

-The master trim air valve closes. -The pack output temperature operates in the backup mode. -The cabin temperature panel control of the upper deck and crew rest zone temperatures is inhibited. -PTC A is selected and both automatic and manual selection of PTC B is inhibited unless PTC A fails.

When will the air conditioning ZONE RST SYS FAULT illuminate?

-A temperature zone duct overheat or ZTC fault has occurred OR -The master trim air valve has failed closed OR -The Trim Air switch is OFF OR -The master trim air valve is closed and pack air continues to flow.

What causes the TEMP ZONE advisory EICAS message

-A zone duct overheat is detected OR -The master trim air valve has failed closed OR -If the ZTC has failed.

What happens to the air conditioning system when TEMP ZONE advisory EICAS message is displayed?

The master trim air valve is closed and the pack temperature control operates in the backup mode.

What does pressing the ZONE RST switch do?

If no fault remains, it will reopen the master trim air and lower lobe cargo trim air shutoff valves.

How does The pilot know trim air is not available to the Flight Deck, Upper Deck, Crew Rest, and Main Deck areas?

-The EICAS advisory message of TEMP ZONE is displayed -The center section of the bleed duct is isolated -The EICAS advisory message of TRIM AIR OFF is displayed -The Master TRIM AIR switch is OFF.

What controls the temperature in the main and upper areas when Trim air is failed or off?

Temperature control backup

How can you clear the temperature control backup mode?

Positioning the temperature control selector from AUTO to MAN or MAN to AUTO.

The packs supply air at what temperature?

At the coldest zone requested temperature

The ______________ selector is used to determine how much air from a pack is delivered to a specific lower lobe cargo compartment.

Lower Lobe Cargo Conditioned Air Flow Rate

The Flt Deck Temp selector can automatically adjust the temperature between _________-__________

18C -29C

If a fault or duct overheat no longer exists an attempt to restore zone temperature control can be made by pushing the ___________.

Zone Reset switch

TEMP CARGO HEAT EICAS advisory message

Overheat cargo detected in aft cargo

T/F: The heated air from the E&E compartment heats the forward cargo compartment.

True

The Aft Cargo Heat Switch is normally ______ before engine start.

OFF

In the A/C, what happens when the MAIN cargo fire system is armed?

E/E is cooling to closed loop to starve the affected zone of fresh air, minimize air movement, purge smoke from the flight deck and passenger cabin, and insure the supply of fresh air to the flight deck.

In the A/C, what happens when the FWD or AFT cargo fire system is armed?

E/E is cooling goes to smoke override, to starve the affected zone of fresh air, minimize air movement, purge smoke from the flight deck and passenger cabin, and insure the supply of fresh air to the flight deck.

How is cabin pressurization controlled?

2 outflow valves

What controls the outflow valves?

The cabin altitude controller A/B

Do we need both outflow valves to maintain pressurization?

What happens if both outflow valves fail?

Positive and negative pressure release valves are provided by mechanical relief

When will positive pressure relief valves open?

9.4 psid

What will happen automatically if the positive pressure relief valve opens?

Pack 2 will shutdown.

PREE RELIEF EICAS advisory message

Either pressure relief valve open with all packs operating

Max cabin pressure Differential

9.4 psid

Max cabin pressure differential for takeoff or landing

.11psid

What powers the outflow valves?

AC motor automatic DC motor manual

What is the function of the cabin altitude limiter?

Closes both outflow valves in the event cabin altitude exceeds 11,000'

How can the cabin altitude limiter be bypassed?

By selecting Outflow valve Manual to ON

OUTFLOW VLV L , R EICAS advisory message

Automatic control of the outflow valve inop, or Outflow valve manual switch ON

CABIN ALT AUTO EICAS caution message

Both cabin altitude controllers inop or both outflow valve manual switches ON

What protections are there when both outflow valves are in the manual mode?

Only the mechanical pressure relief valves

When will the PRIMARY EICAS display pressurization information?

-The landing altitude is manually selected, or -The cabin altitude is in a caution (amber) or warning (red) range, or -The cabin differential pressure is in a caution (amber) or warning (red) range, or -Either the ECS or ENG synoptic is selected for view on the Secondary EICAS display.

When will ECS Duct pressure turn amber?

at 11 psi or less

LANDING ALT EICAS advisory message

Disagreement between controller landing altitude and FMC landing altitude or landing altitude in MAN

What altitude will the cabin altitude controllers in cruise mode assume if no cruise altitude is available from the FMC?

39,000'

What is the normal cabin altitude range?

8,000' or less

When will pressurization descent mode activate?

Reaching TOD or the aircraft descends more than 1,000' from cruise altitude.

What is the Available landing elevation range?

1,000' bsl to 14,000' asl

What altitude will the cabin altitude controllers upon landing assume if no cruise altitude is available from the FMC?

2,000'

If landing above 8,000' what altitude will be manually selected in the LDG ALT?

8,000'

The maximum cabin differential pressure is ______psi.

9.4

With the pressurization AUTO SELECT switch in the A position ______________________

the A controller is designated as the primary but the B controller is selected if the A controller fails.

Selecting an Outflow Manual Switch to ON bypasses the _________ and _________ for the selected valve.

Automatic control, cabin altitude limiter