Air System Flashcards
What sources supply air to the bleed air (pneumatic) system?
Engines, APU, External High Pressure Air
What systems rely on bleed (pneumatic) air for operation?
Air Conditioning/Pressurization, Wing/Engine Anti-Ice, Engine Starting, Hydraulic Reservoir Pressure, Water Tank Pressure, Nitrogen Generation System
What is the purpose of the Engine Bleed Air Valve, and how is it operated?
Pressure regulator and shutoff valve. DC-controlled, pressure-operated.
What is the purpose of the Precooler System?
Regulates (cools) the temp of the Engine bleed air down via an air to air heat exchanger.
What causes Bleed Trip Sensors to automatically close the Engine Bleed Air Valve? What is the indication?
Excessively high engine bleed air temperatures (254c)
Excessively high pressure (220 psi)
What causes Bleed Trip Sensors to automatically close the Engine Bleed Air Valve? What is the indication?
Excessively high engine bleed air temperatures (254c)
Excessively high pressure (220 psi)
BLED TRIP OFF (amber) light
Can the bleed trip condition be reset?
Yes with the TRIP RESET switch if the exceedance(s) no longer exist
Where does the APU Bleed Air Valve provide air to? How is it controlled/operated?
APU bleed air to the left duct
With the APU Bleed Switch which is DC-Controlled, pneumatically operated
What is the purpose of the Isolation Valve?
Isolates the left and right bleed air ducts during normal ops.
What is the position of the Isolation Valve in Auto?
Isolation valve will auto close when both engine bleed ON and Both PACKs AUTO/HIGH and switching any to off (four corner switches)
What does a DUAL BLEED (amber) light indicate?
Illuminates when the APU Bleed Air Valve is open and:
Engine 1 Bleed Switch is On and/or
Engine 2 Bleed Switch is On with the isolation valve open.
What does the WING-BODY OVERHEAT (amber) light on the Bleed Air Panel indicate?
Indicates an overheat has been detected.
What is the primary source of conditioned air for the flight deck? Passenger cabin?
Flight deck: Directly from the Left pack.
Passenger Cabin: Excess air from the Left pack, air from the Right Pack, and air from the Air Recirculation System
Where does the Mix Manifold mix air come from?
Left and Right Packs, as well as recirculated air
A single pack in high flow mode can maintain pressurization to what altitude
FL410
What is the AUTO logic of the Pack Switches with a pack or engine failure
With the flaps up if an Engine or a Pack fail the operating Pack automatically goes into HIGH mode.
What is indicated by the PACK (amber) light on the Bleed Air Panel?
Indicates failure of both the primary and standby pack controls for the same pack.
How is the PACK system cooled?
PRIMARY HEAT EXCHANGER: Bleed air is introduced into the exchanger where ram air lowers the bleed air temperature.
What is indicated by bright blue RAM DOOR FULL OPEN light?
Illuminates whenever a ram door is fully open.
What is the purpose of the recirculation fans?
-Reduce load on engines
-Increase cabin humidity
-reduce airborne particulates and micro-organisms in the cabin using HEPA filters
What are the zones of the temperature control? How are temperatures controlled?
Flight Deck, Forward Cabin, Aft Cabin
Through the Air Conditioning Panel using the Trim Air System
What does ZONE TEMP (amber) light indicate?
Indicates a supply duct overheat and the associated Trim Air Modulating Valve closes.
What limitations, if any, are there when using external pneumatic air?
Both PACK switches should be positioned to OFF
Which, if any, of the cargo compartments are heated?
Forward Cargo compartment.
