Pneumatics

Question 1

What is the function of the Air Management System Controller, (the dual-channel, software based, electronic digital controller)?

Answer 1

It continuously monitors the performance of the pneumatic system components, the WHSAIS as well as the airflow schedule of the ACS and maintains system functionality through system logic.

Question 2

What sub-systems are considered pneumatic?

Answer 2

Air conditioning, cabin pressurization, wing and horizontal stab anti-ice system

Question 3

How is the bleed system controlled?

Answer 3

By two bleed Pressure Regulating Shutoff Valves (PRSOV) located in each pylon.

Question 4

What are the functions of the two Pressure Regulating Shutoff Valves (PRSOVs)?

Answer 4

They regulate the hot bleed air released to the ECS and AIVs and provide a
firewall shutoff capability for the bleed air lines.

Question 5

What would you expect regarding the AMS if the temperature were above 30c?

Answer 5

A white crew awareness CAS message stating that one or both bleed valves has
closed, which can be verified on the ECS schematic page.

Question 6

Does a PRSOV automatically close in case of a single engine takeoff condition?

Answer 6

Yes

Question 7

Can the remaining bleed air then supply all of the bleed air required by the system?

Answer 7

Yes, via the Cross Bleed Valve, (XBV).

Question 8

How can the pilot override the RH PRSOV to the closed position?

Answer 8

By placing the pneumatic Bleed 2 toggle switch to the OFF position.

Question 9

What does turning the ECS knob to OFF VENT do?

Answer 9

Opens the Ram Air Valve (RAV) in the rear fuselage providing fresh air to both the cabin and cockpit, closes both FCSOVs (ECSs), and closes both PRSOVs (bleeds).

Question 10

What two modes control cockpit and cabin temperature?

Answer 10

Auto and manual mode.

Question 11

How does the crew transfer cabin temp control to the passengers?

Answer 11

By dialing the Cabin Temp Knob full counter-clockwise into the detent.

Question 12

How is temperature of the air to the cabin controlled?

Answer 12

Temperature Modulating Valves (TMVs) mix cooled air from the heat exchangers with hot bleed air based on temperature selection on the cockpit control panel.

Question 13

What is the function of the Vapor Cycle System, (VCS)?

Answer 13

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).

Question 14

When can the VCS be operated on the ground?

Answer 14

With GPU power, or one engine operating.

Question 15

What is used to cool the heat exchanger?

Answer 15

Ground cooling fan on the ground or ram air in flight.

Question 16

For the pressurization system to operate automatically, what input is required by the flight crew prior to departure?

Answer 16

LFE must be set.

Question 17

What is the purpose of the Dump Button?

Answer 17

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.

Question 18

Where is the Outflow Valve located?

Answer 18

It is mounted on the aft pressure bulkhead

Question 19

What is the purpose of the negative and positive relief valves?

Answer 19

They are designed to prevent over or under pressurization of the fuselage; they are not actuated during normal operation.