Section II – Air Systems Flashcards
What is the significance of a Compartment Temperature INOP light when it is illuminated?
Fault in the zone temperature controller, Associated controller is OFF, and/or Trim air switch is in the off position.
With respect to the Cabin Altitude AUTO RATE control, at what rate will the pressurization system establish a climb and descent when set to the index mark?
Index mark establishes 500 fpm climb and 300 fpm descent.
What is the significance of the Pack INOP light when it is illuminated?
The pack is overheated,the pack outlet temperature is high , there is a fault in the automatic control system. ( reset possible thru QRH )
What is accomplished by pushing a PACK RESET switch?
It resets an overheated pack if the pack has cooled to a temperature below the
overheat level.
What is the available temperature range of a compartment temperature controller?
Rotating the control toward C (cool) or W (warm) sets the desired temperature between 65 F (18C) and 85 F (30C).
Describe a situation that would cause the AUTO INOP light to illuminate on the pressurization panel?
The AUTO INOP light illuminates when automatic pressurization control fails (1 & 2) or when cabin altitude mode selected is MAN.
When does the pressurization system begin pressurizing the airplane under normal operations?
On takeoff, the system supplies a small positive pressurization to cause a smooth cabin altitude transition
When does the pressurization system enter the “cruise” mode?
Shortly after the airplane levels off, the system enters cruise mode. The landing altitude and the scheduled cabin altitude are compared and the higher of these two is selected for the cruise cabin altitude.
What scenario would cause a BLEED light to illuminate on the overhead bleed panel?
a. 767-200: The engine high pressure bleed valve is open when it should be closed.
b. 767-300: The engine high pressure bleed air valve or pressure regulating valves are open when it should be closed.
What are some systems that require the use of engine bleed air?
Air Conditioning, Pressurization, Engine Start, Wing and Engine Anti Ice, ADP,Hydraulic Reservoir pressurization, Thrust Reversers (-300 only).
What is accomplished by selecting an engine bleed switch into the ON position (engines not running)?
Arms the associated bleed valve to open when bleed pressure is sufficient to cause forward flow. The valves are pressure regulated and remain close until engine bleed air is sufficient to cause forward flow.
Under normal operations while in flight, the L + R ISLN valves are normally _________ while the C ISLN valve is normally __________ ? (2.40.2)
a. Closed (selected out, no flow bar) b. Open (selected in, flow bar).
What scenario would cause the NO COOLING light to illuminate on the equipment cooling panel?
Active in the OVRD mode only; means there is no reverse air flow through the E/E avionics
What would cause the CABIN ALTITUDE light on the equipment cooling panel to illuminate?
When the cabin altitude exceeds 10,000 feet. Extinguishes when cabin altitude descends below 8,500 feet.
How many fans recirculate air through the equipment cooling system while the aircraft is on the ground? How many operate while in flight?
a. (2) While on the ground, a supply fan and exhaust fan either recirculate the cooling air back in the system or port it overboard.
b. (1) While in flight, only the exhaust fan operates, and the air is recirculated through the system.
What is the significance of a VALVE light when illuminated on the equipment cooling panel?
a. The VALVE light illuminates if the system fails to reconfigure during automatic operation.
What would cause an engine HP (high pressure) compressor valve to automatically open?
HP air is used during descent and other low power setting operations.
What is the maximum NORMAL cabin pressure differential?
The maximum normal cabin differential pressure is 9.1psi.
In flight, APU bleed air is available up to what altitude?
17,000 feet.
What temperature will the pack provide if you have 3 different temperatures selected ?
The pack will provide the lowest of the 3 temperatures and trim with hot air thru the trim air valves.
What do the packs do when the trim air valves are inoperative or trim air switch is off
During operation with the trim air system off, the packs attempt to maintain all compartments at an average temperature
What is the significance of PACK OFF and INOP light on the overhead panel ?
A pack INTERNAL overheat exists.
What valves need to be open in order to have air supplied to aft cargo heat ,center hydraulic res. and ADP with engines running and APU off ?
Center isolation valve for all of the above. If APU is ON then it does not need to be open.
The ground pneumatic ground cart is on what side of the system ? If you are attempting to start the right engine with a APU INOP and a ground cart what switches need to open ? How about the left engine ?
Ground pneumatic is on the left side . Only the Right Isolation valve would need to open . The left engine will start regardless of isolation valves switch positions
If you have a BLD DUCT LEAK message and the bleed source has been turned off what does it indicate ?
There is a bleed duct leak between the L ISLN and R ISLN valves
A PACK TEMP message has appeared and you select a standby mode such as N,C,W how long must you wait before resetting the pack ?
5 minutes per QRH
In OVRD mode what happen with the equipment cooling system ?
All valves close except the smoke override valve . Fans off.
What does each cargo heat switch control ? What areas do they control ?
Controls the shutoff valve and the heat control valve. The lower cargo areas
Explain the operation of the bulk cargo heat switch positions .
In normal it works the same as the other cargo compartments ( maintains 45 f ) and in vent is controls to a higher temperature ( 65 f ).
Does the airplane land with positive or negative pressure ?
During the descent the cabin pressurization controller decreases cabin altitude below selected landing altitude to ensure a POSITIVE pressure on landing.
If the cabin altitude exceeds what altitude will command outlflow valve FULL closed ?
11,000 feet cabin altitude
What systems prevent cabin pressure from exceeding max differential or negative cabin pressure ?
The positive and negative pressure relief valves
