Pneumatics Flashcards
What is the function of the Air Management System Controller, (the dual- channel, software based, electronic digital controller)?
Monitors the performance of the:
- heating and cooling
- WHSAIS
- pressurization
Maintains system functionality through system logic.
What sub-systems are considered pneumatic?
3
Air conditioning, cabin pressurization, WHSAIS (wing and horizontal stab anti-ice system)
How/where is the bleed system controlled?
By two bleed Pressure Regulating Shutoff Valves (PRSOV) located in each pylon.
What are the functions of the two Pressure Regulating Shutoff Valves (PRSOVs)?
(2)
Regulate the hot bleed air ( released to the ECS and AIVs) Provide a firewall shutoff capability for the bleed air lines.
What would you expect regarding the AMS if the temperature were above 30c on the ground (WOW)?
A white crew awareness CAS message stating that one or both bleed valves has closed. At TO/GA power they will open.
(which can be verified on the ECS schematic page)
Does a PRSOV automatically close in case of a single engine takeoff condition?
Yes
In case of a single engine takeoff condition, the PRSOV closes automatically. Can the remaining bleed air then supply all of the bleed air required by the system?
Yes, via the Cross Bleed Valve, (XBV).
How can the pilot override the RH PRSOV to the closed position?
By placing the pneumatic Bleed 2 toggle switch to the OFF position.
What does turning the ECS knob to OFF VENT do?
3
Opens the Ram Air Valve (RAV) in the rear fuselage providing fresh air to both the cabin and cockpit
Closes both FCSOVs (ECSs)
Closes both PRSOVs (bleeds)
What two modes control cockpit and cabin temperature?
Auto and Manual
How does the crew transfer cabin temp control to the passengers?
By dialing the Cabin Temp Knob full counter-clockwise into the detent.
How is temperature of the air to the cabin controlled?
Temperature Modulating Valves (TMVs) mix cooled air from the heat exchangers with hot bleed air based on temperature selection on the cockpit control panel.
What is the function of the Vapor Cycle System, (VCS)?
Provides cooling air for the cabin and cockpit and is operated automatically by the ECS controller. (The VCS uses a refrigerant, evaporators, condenser and a fan to produce the cold air).
When can the VCS be operated on the ground?
With GPU power, or one engine operating.
What is used to cool the heat exchanger?
ground vs. flight
Ground cooling fan on the ground or ram air in flight.
For the pressurization system to operate automatically, what input is required by the flight crew prior to departure?
LFE must be set.
What is the purpose of the Dump Button?
Provides cabin depressurization by opening the outflow valve. If pressed a second time, the system returns to normal. It also turns off the recirculation fans.
Where is the Outflow Valve located?
It is mounted on the aft pressure bulkhead .
What is the purpose of the negative and positive relief valves?
They are designed to prevent over or under pressurization of the fuselage; they are not actuated during normal operation.
The ECS dial switch on the pressurization panel does what?
Opens and closes FCSOVs, Flow Control Shutoff Valves, and can open the ram air in off/vent.
When you hit the DUMP button?
Opens outlaw valve and turns off recirc fans.
The outflow valve is a ____ second valve?
6 seconds to fully open or close.
Pneumatic panel off and auto switch controls what?
PRSOVs at the pylon.
The temperature rheostats in the cockpit control what?
Temp through the TMVs (temperature modulating valves)
If you hit the DUMP button and then reset it does everything reset?
Yes
