Pneumatics And Pressurization Flashcards
Pneumatics provides compressor air for what systems?
ECS
Pressurization
Wing anti ice
At what stages does compressor air get used for pneumatics?
P2.5
P3
What is P2.5 air used for?
ECS and pressurization
What is P3 air used for?
Wing anti ice
When would P3 air be used for ECS instead of P2.5 air?
Idle power or less than 36 psi on P2.5
At what Ng and psi does the P2.5 line carry the ECS load?
62% Ng or 43 psi
At what pressure is bleed air supplied to the wing anti ice system?
14 psi
When must ECS be shutoff?
Engine fire suspected
When would ECS automatically shut down?
Pressure greater than 40 psi (high pressure)
290 C upstream of shutoff valve (high temp)
105 C downstream of water separator (high temp)
Firewall SOV closed
What component provides air for the ECS system?
Air cycle machine
What will happen in the cabin if the ECS firewall shutoff is pulled?
Pressurization cannot be maintained
CPCS components
Outflow valve
Safety valve
Manual control valve
Auxiliary volume tank
Check valve
Ejector valve
Solenoid valve
Where is the outflow valve located?
Bottom right firewall
How can you depressurize the aircraft after an aborted takeoff?
Dump switch
Where is the safety valve located?
Bottom left firewall
What is the function of the safety valve and when does it open?
Opens automatically between 6.15 and 6.35 psi
What does the check valve do?
Prevent high pressure air from entering the control unit when a system blockage occurs
What is the function of the ejector valve?
Operates the outflow valve
What is the function of the solenoid valve?
Depressurizes aircraft from the squat switch or the condition lever
Cabin rate of climb can be adjusted within what range?
100 fpm and 2000 fpm
Pulling the ECS emergency shutoff handle does what?
Closes the outflow valve
Opens the ram air scoop
When would you get a cabin pressure warning on the CAWS panel?
Cabin altitude 10,500 (+/- 200)
>5.75 psi differential
Set cabin altitude is maintained unless…
AC descends below selected altitude
AC climbs and max pressure differential is reached
Pilot changes the setting
What cabin altitude would be reached at 30,000’?
10,000
Where should the controller be set for landing?
500’ above field elevation
Cabin rate of descent should be set how?
To achieve LFE set prior to getting to that altitude (descend the cabin faster than you get there)
What ensures no pressure bump when landing?
Cabin pressure will maintain 150’ (+/- 100) below field elevation on landing
What should you do if the cabin controller fails?
Use manual control
Where should you check pressurization during flight?
After takeoff and at 10,000’
