Pneumatic, Bleed Air Flashcards
What pneumatic sources are available on the ground?
APU, ground air source, or engines
What pneumatic sources are available in flight?
Either operating engine and/or APU
What does the Engine Bleed Air OFF light indicate?
Engine bleed air valve closed
How is the APU protected from reverse air flow?
System logic and a check valve
After the aircraft is secured for flight but prior to engine start someone notices that
there is no bleed air pressure with the APU running. Is there a procedure for this
non‐normal condition?
Yes, the procedure can be found in AOM chapter 4,
supplemental
What systems rely on pneumatics?
Air conditioning/pressurization and engine start
What does the APU Bleed Air VALVE light indicate?
APU bleed air valve position disagrees with signaled
position or valve in transit
What does the Isolation VALVE light indicate?
Isolation valve position disagrees with commanded
position
(757) What does the HI STAGE light indicate?
Engine bleed system pressure is excessive
(757) What does the BLEED light indicate?
Indicates bleed air temperature is excessive
(757) What does a DUCT LEAK light indicate?
High temperature bleed air leak is detected
(757) What is indicated with an Engine Bleed Air OFF light and L or R ENG BLEED OFF
EICAS message illuminated?
Engine bleed air valve is closed for a system fault
(767) What does the OVHT light indicate?
Engine bleed air temperature is excessive
(767) What does the BLEED light indicate?
Engine high pressure bleed air valve and/or pressure
regulating valves are open when they should be closed
(767) What does a DUCT LEAK light and EICAS message indicate?
High temperature bleed air leak is detected
