Air Conditioning And Pressurization Flashcards
What is normally operating max differential pressure as applied by the controller
7.46 psi
At that differential pressure what is the cabin altitude at 35000 ft
8000ft
What is the diff pressure limited by the outflow valves
7.65
Cabin Alt limiting at 12500ft +/- 1500ft
What is the altitude limiter set to
12000ft +/- 1500ft
What warning is there of excessive cabin altitude
An excessive cabin Altitude warning is presented when the cabin Altitude reaches 10000ft
How is the fuselage protected against negative pressure
The cabin is automatically depressurised upon landing, two inward pressure relief valves prevent negative cabin pressure
How do you set the panel for automatic operation
Set the landing elevation and rate control knob in the datum.
What happens if the active Channel fails
The standby channel takes over, level 1 alert
How do you manually change channels on the controller
Pressing the PRESS CONTROL p/b twice in succession
What happens if both channels fail? What do you do
Manual mode is automatically activated and an alert is generated level 2 alert CAB PRESSURE CONTROL
How do you control pressurisation in manual
Bu selecting PRESS CONTROL p/b and the up and down toggle and decrease or increase the rate with the rate knob
What pressurisation alerts are there and at what level
CABIN PRESSURISATION CONTROLLER CHANEL FAULT- level 1
CABIN PRESSURISATION CONTROLLER FAULT—level 2
EXCESSIVE CABIN ALTITUDE— level 3
how many air conditioning packs are installed
Two, Pack 1 and Pack 2
Is a single pack enough to satisfy the requirements
Yes single pack can meet all requirements
Which pack supplies what area
Pack 1 serves Flightdeck
Pack 2 serves cabin
What conditions must be met for a pack valve to open
when pressure is >10 psi and system is on
When will auto shutoff of both packs occur
Auto Shut-off of both packs occurs: - On the ground during engine starting or when both thrust reversers are unlocked. - If an engine failure is detected during take-off or in flight at altitudes below 13 500 ft and a thrust lever setting above MIN TO is selected.
How is pack operation restored after an auto shutoff due to engine failure
In case of an auto shut-off due to engine fail-ure, pack operation is restored by operating the AIRCOND AUTO SHUT p/b located at the ram air panel or by selecting a lower thrust lever setting. Pack operation will be automatically restored when climbing above 13 500 ft
How are normal and economy flows selected
There are three modes of flow control: nor- mal, economy and augmented. Normal and economy flows can be selected manually. Economy flow is obtained when both pack valves are open and the automatically con-trolled cabin temperature is within a preset range from the selected temperature. Econ- omy flow is automatically selected:
What is augmented flow
High output flow of 140%
If you are in economy mode and a pack fails, what happens
How do you select a cabin or Flightdeck temperature
The temperature may be controlled automat-ically or manually via the temperature selec-tors. The air temperature of cabin, cabin supply, and flight deck supply can be dis-played
Where is air temperature displayed
The air temperature of cabin, cabin supply, and flight deck supply can be dis-played on the overhead panel
How is the flight deck and cabin air distributed
Conditioned air from the manifold is distrib- uted to the flight deck and cabin via indepen-dent ducts
How many recirculating fans are there, what do they do and how are they controlled
4 fansCabin air is distributed overhead along each cabin wall. The cabin air can be recirculated by four recirculation fans which are mounted in the cabin ceiling. The fans are controlled by the RECIRC FANS p/b’s
How and when would you introduce Ram air into the aircraft
During unpressurized flight ram air may be introduced to the manifold via a valve. Control is by the RAM AIR p/b located at the ram air panel
What happens to the air conditioning system if an engine failure occurs above 13500ft? And below 13500ft
On the ground during engine starting or when both thrust reversers are unlocked. - If an engine failure is detected during take-off or in flight at altitudes below 13 500 ft and a thrust lever setting above MIN TO is selected. In case of an auto shut-off due to engine fail-ure, pack operation is restored by operating the AIRCOND AUTO SHUT p/b located at the ram air panel or by selecting a lower thrust lever setting. Pack operation will be automatically restored when climbing above 13 500 ft.
Is there anytime the automatic switch to economy flow will not work
Economy flow is inhibited when both temper-ature control p/b’s are in manual mode and 1 pack is off
If an external air conditioning unit is supplying ventilated air, what precautions must you take and why
Open avionics hatch or cockpit windows before connecting the unit
What would you do to reduce cabin air temperature during ground ops and initial flight
Low pressure conditioned air can be supplied to the manifold for distribution throughout the aircraft via a ground connection provided at the forward right section of the aircraft.
