B747-400 PRESSURIZATION EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS VERIFIED
How is the pressurization controlled?
Regulating the discharge of air from the two aft mounted outflow valves.
How are the outflow valves controlled?
By the cabin altitude controller A or B, or MANUALLY.
What happens if one outflow valve fails?
The remaining valve can maintain full cabin altitude & full ventilation rates.
When the two cabin outflow valves cannot maintain pressure, what other devices
are available?
Positive & Negative pressure are provided by mechanical relief valves.
When will the positive pressure relief valve open?
9.4 PSI
While either valve is open, WHICH pack will shut down to assist in relieving
excess cabin pressure?
Pack 2
Where are the negative pressure relief valves located?
Forward & Aft Cargo doors
What other functions to the negative pressure relief valves provide?
Relieve any positive pressure on the ground. Assists in ground crew handling.
Maximum Allowable Cabin Pressure Differential For Takeoff & Landing
, .11 psi
What modes does the pressurization come equipped with?
Automatic & Manual
How are the outflow valves powered?
AC & DC Motors
Which mode utilizes DC power? AC power?
Manual, Automatic
What automatic inputs are provided by the FMS?
Takeoff elevation
Cruise altitude
Landing field elevation
When the Manual Outflow valves in the OFF position, the pressurization operates
in the ________________ mode.
Automatic
No specific flight crew action is required for flights with a landing elevation below
______________.
8,000 feet
How many cabin altitude controllers are there?
2
What if one cabin altitude controller fails?
The remaining takes over
The _______ position on the Cabin Altitude Selector will allow for automatic
switching of the primary controller (A or B)
WITH COMPLETE SOLUTIONS VERIFIED
How is the pressurization controlled?
Regulating the discharge of air from the two aft mounted outflow valves.
How are the outflow valves controlled?
By the cabin altitude controller A or B, or MANUALLY.
What happens if one outflow valve fails?
The remaining valve can maintain full cabin altitude & full ventilation rates.
When the two cabin outflow valves cannot maintain pressure, what other devices
are available?
Positive & Negative pressure are provided by mechanical relief valves.
When will the positive pressure relief valve open?
9.4 PSI
While either valve is open, WHICH pack will shut down to assist in relieving
excess cabin pressure?
Pack 2
Where are the negative pressure relief valves located?
Forward & Aft Cargo doors
What other functions to the negative pressure relief valves provide?
Relieve any positive pressure on the ground. Assists in ground crew handling.
Maximum Allowable Cabin Pressure Differential For Takeoff & Landing
, .11 psi
What modes does the pressurization come equipped with?
Automatic & Manual
How are the outflow valves powered?
AC & DC Motors
Which mode utilizes DC power? AC power?
Manual, Automatic
What automatic inputs are provided by the FMS?
Takeoff elevation
Cruise altitude
Landing field elevation
When the Manual Outflow valves in the OFF position, the pressurization operates
in the ________________ mode.
Automatic
No specific flight crew action is required for flights with a landing elevation below
______________.
8,000 feet
How many cabin altitude controllers are there?
2
What if one cabin altitude controller fails?
The remaining takes over
The _______ position on the Cabin Altitude Selector will allow for automatic
switching of the primary controller (A or B)
