Pneumatics And Air Conditioning Flashcards
How many bleed sources are there per engine?
2 (NL and NH)
When does Nh bleed air help to supply the pnuematic system?
when pnuematic pressure is below 55PSI in the air or below 65PSI on the ground
When does the 18PSI system recieve pressure
when the engine is on
BLEED HOT
bleed air exceeds 287 deg. valves auto close
If one bleed valve is closed, will pressurisation be affected?
No
What do the air conditioning packs provide?
conditioned air to the cabin and flight deck, air for pressurisation
If one air con pack is off will pressurisation be affected?
No
How many air con packs are there?
2
If both packs are off will pressurisation be affected?
Yes - no bleed air in
CABIN PACK HOT
1 pack air cycle machine exceeds 207deg or 75psi. Auto shutoff/valve close
FLT COMP PACK HOT
2 pack air cycle machine internal temp 207deg or 75psi. Auto valve shutoff
How is the Air conditioning system controlled in manual mode?
with the cold/hot toggles
How many outflow valves are there?
3 (2 AUTO rear, 1 manual front)
How are the rear outflow valves opened and closed?
using 18PSI against a spring, controlled by the pressure controller unit
What happens if the aircraft lands pressurised?
the cabin will climb at 600ft/min for 1min then dump (with less than 2.5PSI diff)