Air Conditioning Flashcards
How long does it take to move the ram air modulating valve through full travel using the manual toggle?
15 seconds.
At what temp does duct o’heat illuminate?
148°C
300°f
List three ways the windshield heat s.o.v. Could be opened?
- Select windshield bleed high or low.
- Place air source select to emer.
- Have a total d.c. electrical failure.
If the pylon air inlets were covered with tape what would be affected? Would the precooler ability be affected?
- Cabin heat exchanger and
- windshield Anti-Ice heat exchanger,
- fresh air ability with air source select knob.
No! The preecooler uses Fan Bypass air.
How is the flow of the fan bypass air for the precooler controlled?
Automatically, by a 23psi modulating valve.
How is cabin heat controlled,
mechanically speaking, and from the cockpit?
Mechanically controlled by a modulating valve that controls the amount of pylon ram air through the cabin heat exchanger.
From the cockpit by moving the hot / cold toggle switch in manual mode or by selecting a temp in auto mode.
If there were a total loss of dc power would emer pressurization be available?
No.
The emergency pressure valve is failsafe closed.
The cabin air temperature in the AUTO mode will keep the cabin temperature in a selectable range of?
18°C to 29°C
65°F to 85 °F
You are just about to initiate a gpu start on a hot day in vegas, when the passenger complains his overhead vents don’t work. How would you respond?
Advise that is normal until an engine is running.
You notice a foul odor comming from a diaper change going on in the cabin while taxiing out. What would be your best course of action? It happens again in cruise what would you do different and why?
On the ground select fresh air (air source select knob)to allow maximum ventilation. In the air fresh ai would depressurize the cabin so manual cab alt select and raise the cabin alt. would be more advisable.
What is the normal temp. range of bleed air after the precooler and what temp.triggers a bleed o’heat caution?
450-500°F (232°C - 260°C) is normal
560°F (293°C) triggers the BLD AIR O’HEAT
You have the air source select in L and passing FL180 get a L bleed air o’heat. Assuming you take no action what will happen?
The L overheat will cause the L prsov to close causing the cabin to depressurize at a normal leak rate.
Your cruising along at altitude when you decide some fresh air is in order. You turn the air source to fresh air and the cabin starts to lose pressurization. You expected that, but your not getting any fresh air…what gives?
The residual cabin pressure will prevent fresh air from entering the cabin until the cabin diff. leaks down.
Which way do the prsov valves fail in a total electrical failure?
They fail as if BOTH was selected on the air source select knob.
L&R PRSOV and windshield Anti-Ice Control Valve fail open,
Cabin Emergency Pressurization Valve fails closed.
