Air Systems Flashcards
what are the 3 sources of high pressure air
Engine bleed Air, Apu bleed, external air
Pnuematic system supplies
Air conditioning/pressurization, engine starting, wing and engine anti-ice, hydraulic reservoir head pressure
Isol valve is only a manual valve?
True (Open and Close)
Describe the “bleed air malfunction” HI STAGE light illumination
At low idle settings, low bleed air may not be enough and can kick to h bleed automatically (no indication of this). If high bleed over pressures the system HI STAGE illuminates and auto locks hi stage bleed valve closed
L or R Eng Bleed Air amber message means
Automatically due to system fault, the switch is off, the engine is not running.
Can APU bleed air be ran for anti-ice operation
NO
Can you use one air start cart for engine starting?
Yes, but only if it has two connections or hoses. Also can use two carts, both having one hose.
Leak detection loops protect which areas
APU, L/R and Crossover
What indications of a duct overheat
Caution Beeper, BLD Duct Leak on eicas, DUCT leak on overhead
767 - how many ducts?
L isol, R isol, C isol, not automatic
How many controllers for pressurization?
2 auto controllers.
What indications that both controllers have failed
Auto INOP light illuminates
When does cabin altitude light illuminate and extinguish?
C A exceeds 10,000 ft and when it returns below 8,500 ft.
What 4 pieces of date do controllers use?
ADS for ambient pressure, selected cabin auto rate, takeoff alt, selected landing alt
What does the auto rate set at index for preflight indicate?
500fpm climb and 300 fpm descent
How is the outflow valve controlled?
auto = AC and Manual = DC
Location on Positive and Neg Relief valves on 757/767
757 - positive relief valve is aft left and neg relieve is fwd right
767 - two negative relief valves on each cargo door and one forward of positive relief valve.
What makes up the air conditioning system?
Two packs, two controllers, mix manifold and Recirc fan
How many compartments?
3 Deck, FWD and AFT
PACK INOP light indicates?
Pack outlet overheat or fault in the automatic controller system
Pack in auto position means
Pack flow valve is open
Any indications of flow management for engine failure in flight deck?
No, all flow management is automatic with no indications
Why is the L recirc fan guarded?
essential part of the equipment cooling system, remains on.
Recirc fan inop light if…
Fan fails, switched off, not operating
FWD Cargo Fire armed does what?
Turns both recirc fans off
AFT Cargo Fire armed turns both recirc fans off?
No, just the R recirc fan.
Does fuel consumption increase with recirc fans off?
Yes, slight increase in fuel consumption with each fan that is off
What is Trim air?
Warm air mixed into compartments, used to differentiate between compartments. If no trim air the compartments will all maintain constant temps. Trim air is controlled with auto compartment air selector.
Shoulder and Foot heaters work on the ground and in flight?
No, just in flight.
Equipment OVHT light illuminates if…
Either supply fan fails or inop, overboard exhaust valve is closed with the L recirc fan failed or switched off
Can you select another supply fan?
Yes ALTN can be selected manually, with some a/c this is automatic and will not receive an OVHT light
FWD EQPT SMOKE light illuminates if smoke in the system and turns off when…
Both recirc fans are turned off and the slats are in the up position, PACKS to high flow when recirc fans are off, overboard exhaust valve opens
Does the AFT equipment cooling have smoke detection?
NO
-300 have how many compartment controllers
4, 2 backup fans for equip, if on 3rd one (Aux fan) non essential avionics and electrical equipment are subject to failure. Aux fan driven by the hydraulic driven gen.
767 - equipment cooling is controlled how?
Automatically based on air temp, air/ground mode and engine operation
767 - what does the OVRD position indicate
reverses airlflow and dumps it overboard. Illumintes no cooling light
767 - OVHT light illuminates for cargo, what does that mean?
Valve closes because temp is high, when it returns to normal around 45 F it will open and the message will disappear
767-Bulk Cargo Heat selector position should be ?
Vent - turns the vent fan on and keeps it at higher than normal temperature
Which a/c has gasper fan?
767-300
Why is the C ISOL guarded on 767?
to prevent damage to air pump.
