Pressurization Flashcards
What are the Ram Air Doors and when would they open?
NACA vents on the underside of the fuselage. Ram air doors in “emergency” position allow ambient air to flow into the cabin but will not pressurize the cabin. They open/go to emergency position any time the aircraft is in flight with both PACKS off.
What is the purpose of the pressurization static ports located on the lower rear portion of the fuselage?
The purpose of the pressurization static ports is to provide over pressure and under pressure relief should the cabin exceed 8.1 psi or -0.3 psi.
What is the function of the DUMP button on the automatic pressurization controller?
The DUMP button will de-pressurize the cabin of the aircraft to an altitude of 14,500’ MSL or the actual altitude of the aircraft, whichever is lower.
Will the DUMP button work if the Digital Controller is set to Manual Mode?
No. The DUMP button will only work if the Digital Controller is in AUTO mode.
Describe the amplified procedure for Pressurization set during the Before Start Check?
Ensure the landing elevation is set in the digital controller. Confirm that the AUTO/MAN pushbutton is set to AUTO (deselected) and guarded. Confirm that the DUMP pushbutton is deselected and guarded. Set the manual controller knob to the full DN position.
Describe the amplified procedure for Pressurization checked during the After Takeoff Check?
Confirm that the aircraft pressurization system is functioning properly:
• Check cabin altitude remains steady
• Check pressurization differential increasing
• Check rate of change remains zero
Describe the amplified procedure for Pressurization checked and set during the Arrival Check?
Verify the field elevation is set in the digital pressure controller and the cabin altitude is trending toward 300 ft. below field elevation.
If landing elevation is not set, what altitude does the Auto Pressurization Digital Controller default to?
If not set, system assumes 8,000’ landing elevation.
What occurs when the DUMP button is pressed (automatic and manual modes)?
- Provides rapid cabin depressurization up to 14,500 ft.
- When pressed, an ON inscription illuminates inside the button.
- This button is effective in the automatic mode only.
What cabin altitude triggers a “cabin, cabin” aural warning?
The CPAM sends a signal to the aural warning system to alert the crew when cabin altitude is above 9,900 ± 100 ft.
Describe Manual Mode Operation?
Manual operation is accomplished through the manual controller which actuates only the pneumatic outflow valve, while the electro-pneumatic outflow valve is kept closed, by selecting MAN in the Pressurization Mode Selector Button and rotating the Manual Controller until the desired cabin rate of change is reached. The crew is responsible for monitoring cabin differential pressure within acceptable values.
In manual mode, the DUMP button is not effective and a rapid cabin depressurization is commanded by turning the manual controller to the UP position (clockwise stop). In this mode, the cabin altitude limitation at 15,000 ft. does not exist as it does in the automatic mode.
