Air systems/Bleed Flashcards
What sources supply air to the bleed air (pneumatic) system?
Eng, APU, Ext.
What systems rely on bleed (pneumatic) air for operation?
Air Cond/Press, Wing/Engine Anti-Ice, Engine Starting, Hyd Res Press, Water Tank Press, NGS
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 Eng bleed air down via an air to-air heat exchanger.
What causes Bleed Trip Sensors to automatically close the Engine Bleed Air Valve?
Excessively high engine bleed air temp, or pressures. Illuminates BLEED TRIP OFF light, AIR COND
annunciator, and MASTER CAUTION.
How is the bleed trip condition reset?
Push the TRIP RESET switch if Condition must no longer exist
What do the WING-BODY OVERHEAT, BLEED TRIP OFF, and DUAL BLEED amber lights on the Bleed Air Panel indicate?
a. WING-BODY OVERHEAT: a duct leak in a critical area
b. BLEED TRIP OFF - Sensors around the Bleed air Valve sense an over temp/pressure
c. DUAL BLEED – 2 sources on left duct, APU and Eng 1 bleed, or Eng 2 bleed and isolation valve open
What is the purpose of the APU Bleed Air Valve, and how is it operated?
APU bleed air to the left duct. DC-controlled, pneumatically operated. APU Bleed Switch
What is the purpose of the Isolation Valve?
Isolates the left and right bleed air ducts during normal ops
What do the Isolation Valve positions CLOSE, OPEN, and AUTO do?
a. CLOSE: remains closed
b. OPEN remains open
c. AUTO - Isolations valve will auto closes when Both engine bleed ON and Both PACKs AUTO/HIGH and
switching any to OFF. (four corner switches)
How do the Engine BLEED Air or Air Conditioning PACK switches impact operation of the Isolation Valve?
a. Turning any engine bleed air switch or pack switch OFF will OPEN the valve
Where is the external pneumatic air connection located?
e right side of the aircraft (immediately aft of the right landing light)
What is the path of conditioned air from an external (ground) source?
Directly into the mixing manifold
. When connected to external air, which position should the PACK switches be in?
off
What is the primary source of conditioned air to the Flight Deck?
Left pack
To the passenger cabin?
Right pack