Pneumatics Flashcards
When is High Pressure P3.0 used?
At low pressure settings to supplement the P2.7 supply.
What is P2.2 Air used for?
To cool higher-pressure air from the other two sources.
How is the Bleed Air Supply System affected by a loss of the Main DC Bus Power?
Both HPSOUs and Nacelle FCSOUs will close.
Where does the APU Bleed Air enter the Bleed Duct.
At the pack control shut off valve PFSOV
Can APU Bleed Air be used if the engines are running?
No
What conditions would bring on a single BLEED HOT Caution?
Over-temperature, over-pressure or a leak in one of the Bleed air ducts, upstream of the Wing Duct Check valve.
What is the function of the Bypass Valves in the Air Conditioning System?
Regulate the temperature of the air sent into the aircraft.
How is Conditioned Air divided between the Flight Deck and the Cabin?
75% Cabin and 25% Flight Deck
What does the Recirculation Fan do?
Draws air from the Cabin and Flight Deck to mis it with outside air.
How does the TEMP CONTROL system function with the Pack Switched in AUTO?
ECU uses the digital channel to control the temperature between 15 and 22 deg C
How does the TEMP CONTROL system function with the Pack Switched in MAN?
Duct Supply Temperatures are directly controlled by the bypass valves between 2.7 and 71 deg C
What determines the relative Cabin Flow Rate to the upper and lower Distribution Ducts?
The Distribution Valve
How is Emergency Ram Air Ventilation accomplished?
Closing the rear outflow valve and opening the forward outflow valve. Must have Packs off and 150 KIAS
How are the Avionics cooled?
An extraction type cooling system. 3 fans DC powered automatically.
How is aircraft pressurisation normally controlled?
Automatically by the cabin pressure controller modulating valve.
How is the fuselage protected from over-pressure or under-pressure?
Two safety valves one on the rear pressure dome and one on the forward bulkhead
What prevents the Cabin from pressurising on the ground?
Aft safety valve and rear outflow valve move to fully open if the PL
When and how does the Forward Outflow Valve function?
To purge smoke from the cockpit, using FWD outflow VALVE selector.
What happens when the DUMP/MAN/AUTO Switch is set to MAN?
Pressurisation diff controlled manually from Pressurisation control panel.
What happens when the DUMP/MAN/AUTO Switch is set to DUMP?
Aft outflow valve is opened fully
How should the LDG ALT Control be set, before departure?
Landing altitude at destination.
What value should be indicated on the DIFF Indicator when climbing through FL100?
4 psi
What is the Maximum permitted DIFF during Taxy, Take-off and Landing?
0.5 psi
What is the Maximum permitted DIFF?
5.95 psi
What is the Maximum permitted Cabin Altitude when pressurised?
8,000ft
When should the CABIN PRESS Warning Illuminate?
At Cabin Altitude 9,800ft
How is Cabin Temperature controlled if APU Bleed Air is being used?
By COLD/WARM selectors on the AC power.
How do the Air Bleed Selector settings of NORM and MAX effect the flow of Bleed air when operating on one Engine?
No effect, Bleed air flow controlled automatically be the ECU.
How is Engine Oil cooled on the ground?
Air is drawn through the Heat exchanger by Ejector valves.
