Manual Mode Operation
A green MANUAL Light illuminates with the pressurization mode selector in the MAN position.
Manual control of the cabin altitude is used if both the AUTO and ALTN modes are
inoperative. In the MAN mode, the outflow valve position switch is used to modulate the
outflow valve by monitoring the cabin altitude panel and valve position on the outflow valve
position indicator. A separate DC motor, powered by the DC standby system, drives the
outflow valve at a slower rate than the automatic modes. Outflow valve full range of motion
takes up to 20 seconds.
A green MANUAL Light illuminates with the pressurization mode selector in the MAN position.
Manual control of the cabin altitude is used if both the AUTO and ALTN modes are
inoperative. In the MAN mode, the outflow valve position switch is used to modulate the
outflow valve by monitoring the cabin altitude panel and valve position on the outflow valve
position indicator. A separate DC motor, powered by the DC standby system, drives the
outflow valve at a slower rate than the automatic modes. Outflow valve full range of motion
takes up to 20 seconds.
| Flight Path Events – Auto Mode |
