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pressurized cabin pressure. This schedule is
referred to as the climb schedule which is dif-
ferent for each takeoff altitude. There is no
fixed climb schedule as there is for descent.
For takeoffs and landings that occur below
8,000 feet the schedule (Figure 12-7) is ap-
plicable. After lift-off, the cabin altitude is
controlled to the takeoff field elevation (-150
feet). As the airplane climbs, the controller
continually checks the climb schedule (aircraft
altitude against the takeoff altitude in the
cabin). When the climb schedule value ex-
ceeds the current cabin altitude, the system be-
gins to rate the cabin up proportionally at a rate
not to exceed 600 fpm until the airplane stops
climbing. The maximum altitude the cabin
will reach is 8,000 feet at an airplane altitude
of 51,000 feet.
If an inflight abort is necessary after takeoff,
the controller retains the takeoff field alti-
tude in a stored memory. This allows the cabin
pressure to return to the takeoff field eleva-
tion if the airplane descends 1,000 feet within
10 minutes after takeoff and is 6,000 feet or
less above the takeoff field elevation (Figure
12-8).
When a descent is initiated from cruise alti-
tude and the airplane has descended 1,000
feet or more below cruising altitude, the con-
troller establishes the cabin altitude on the de-
scent schedule until landing (Figure 12-9).
As the aircraft altitude changes during the de-
scent the cabin altitude also descends, but at a
rate not to exceed 375 fpm until the selected
landing field elevation has been reached.
While in the descent mode (Figure 12-9), if the
controller detects a true airspeed of less than
65 knots and the left thrust lever is below
MCR, or the squat switches sense weight-on-
wheels, the controller enters the landing mode.
Upon landing the system will automatically
open the outflow valves to depressurize the air-
12-15
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
AIR
CR
AFT C
LIM
B
CABIN CLIMB RATE
PROPORTIONAL TO
AIRCRAFT CLIMB
CLIMB SCHEDULE
CALCULATION
COMPLETED
THROTTLES
ADVANCED
LIFT-OFF
1,000 fpm (MAX)
SL
TAKEOFF
FIELD
ALTITUDE
TIME
Figure 12-7. Controller — Takeoff and Climb