Subtask 10.1.5 Operate Air Management System Flashcards
Recite maximum and minimum pressure differential limitations.
8.4 PSI = MAX differential cabin pressure
8.8 PSI = MAX differnential cabin overpressure
-0.5 PSI = MAX differential cabin negative pressure
0.2 PSI = MAX differential cabin pressure for T/O & landing
What happens when the dump button is pressed while the mode selector is in AUTO? LFE CTRL? MAN?
In AUTO or LFE CTRL – provides rapid cabin depressurization by opening the outflow valve and commanding the packs and recirculation fan off. (2000’/min til 12,400)
In MAN mode – the outflow valve will not be commanded open. PACKS and fans turn off.
When would I use the LFE CTRL on the pressurization panel?
When an airport field elevation is not in our database. Allows manual input of landing field elevation, although the pressurization system will remain in automatic mode.
What does the outflow valve do? Positive pressure relief valve? Negative pressure relief valve? Cabin pressure controllers?
Outflow valve- modulates airflow from the pressurized cabin into surrounding environment
Positive pressure relief valve(safety valve)- Spring loaded check valve that works without any electrical power, and is independent of the CPCS. Its function is to protect the airplane structure against damage due to positive overpressure. In case of outflow valve failure, the positive pressure relief valve opens if pressure differential exceeds 8.6 PSI.
Negative pressure relief valve – Spring loaded check valve that works without any electrical power, and is independent of the CPCS. Its function is to protect the airplane structure against damages due to a negative differential pressure.
Cabin pressure controllers – basic function is to control cabin pressure by commanding the outflow valve to modulate airflow through the valve from the pressurized airplane volume to the surrounding environment. Can be operated in automatic or manual mode.
