Cabin Pressurization Panel Flashcards
1
Q
OFF SCHED DESCENT light
A
- aircraft has started descent at least 1,000 ft prior to reaching the altitude set in the FLT ALT window
- if the FLT ALT indicator is changed, the automatic abort capability to the original takeoff field elevation is cancelled
2
Q
ALTN light
A
- indicates pressurization system operating in alternate mode
- selected automatically or manually
- if the mode selector is in AUTO, illumination of both the ALTN and AUTO FAIL lights indicate a single controller failure and automatic transfer to the ALTN mode
3
Q
MANUAL light
A
- pressurization system operating in MANual mode, selected with the mode switch
- operate the outflow valve to maintain proper cabin altitude and cabin rate of change
4
Q
DIGITAL PRESS MODE SELECTOR
AUTO -
ALTN -
MAN -
A
AUTO
- automatic pressurization control (normal mode of operation) uses a DC motor
ALTN
- automatic pressurization control (alternate mode of operation) uses another DC motor
- second of two digital cabin pressure controllers, so auto mode has dual redundancy
- the green ALTN light illuminates if ALTN is selected
MAN
- overrides and bypasses the two cabin pressure controllers
- has its own valve motor system for triple redundant architecture
- 28v dc bat bus power source
5
Q
AUTO FAIL light
A
- illuminates if automatic pressurization system failure detected:
- indicates a single controller failure when ALTN light is also illuminated
- indicates a dual controller failure when illuminated alone
- MASTER CAUTION and AIR COND annunciator lights come on