switch/indicator. Should either ADC input
later become valid, the system automatically
returns to the auto mode.
Whether the manual mode is entered auto-
matically or is manually selected, the cabin
pressure rate control always begins at zero
fpm rate of change, regardless of the position
of the MANUAL DN-UP rotary knob. In man-
ual, the crew can change the cabin altitude by
rotating the knob. As the knob is rotated, de-
tents can be felt which represent rate position
increments. Each detent will command a 100
fpm climb or descent with a limit of + 2,500
fpm.
When the MANUAL rate knob is rotated,
“MR” (manual rate) and the desired vertical
speed value set with the MANUAL rate knob
appears on the line of the LCD that normally
displays CAB RATE-FPM. Five seconds after
the last movement of the MANUAL rate knob,
the display reverts back to actual cabin rate.
It may be more convenient to use the ECS sys-
tem schematic display on the EICAS when
using the manual controller since it displays
actual CABIN RATE and desired MANUAL
RATE at the same time.
During manual mode operation, adjustment of
the landing altitude knob has no effect on the
pressurization system. If manual mode is en-
tered while the airplane is on the ground, the
12-17
FOR TRAINING PURPOSES ONLY
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
FlightSafety
international
ALTITUDE
TIME
CABIN HOLDING
AT DESCENT
SCHEDULE
ALTITUDE
DESCENT
ON CABIN
DESCENT
SCHEDULE
CABIN HOLDS AT
SELECTED LANDING
FIELD ELEVATION
DESCENT RATE
(375 fpm MAX)
CABIN AT CLIMB
SCHEDULE ALTITUDE
AIRCRAFT ALTITUDE
CHANGE EXCEEDS 200 FT
AIRCRAFT ALTITUDE CHANGES
<
±
100 FT WITHIN 1 MINUTE
DESCENT DETECTED
1,000 FT BELOW CRUISING ALTITUDE
MAXIMUM AIRCRAFT
CRUISING ALTITUDE
Figure 12-9. Controller — Descent Mode