• MCR (maximum cruise thrust)
• IDLE
• CUTOFF
The full range of the thrust levers is approxi-
mately 50 degrees from the CUTOFF posi-
tion to the forward stop at APR.
The APR position is a forward limit stop rather
than a detent and is sometimes referred to as
manual power reserve (MPR). This position al-
lows the crew to directly select the additional
thrust that would be provided by APR, but
without arming the system.
From the MCR detent forward, the DEEC only
recognizes four different power settings (i.e.
MCR, MCT, T/O and APR). It is not practical
to try to set power settings between these de-
tents.
When the thrust levers are set to one of the de-
tents, the DEECs individually compute the
N1 for that position based on ambient condi-
tions (temperature, pressure altitude, etc.) and
other computer inputs. The DEECs then po-
sition the N1 bug reference and signals the
torque motor in the fuel controller to sched-
ule fuel to achieve the computed N1. Between
IDLE and MCR, the thrust levers are more
conventional, allowing the operator to set de-
sired N1 manually.
When the thrust levers are positioned to one
of the detent positions, the position selected
is annunciated as a green MCR, MCT, T/O or
APR on the EICAS just outboard of the N1 dig-
ital displays (Figure 7-8).
The IDLE position provides either flight idle
or ground idle depending on the signal from
the squat switches. With the thrust levers at the
IDLE position, flight idle is approximately
65% N2 at low altitude and increases propor-
tionately with altitude. Ground idle (approx-
i m a t e l y 5 2 % N 2 ) w i l l b e c o m m a n d e d 2 0
seconds after the aircraft touches down unless
a higher engine speed is commanded through
the use of the thrust reversers. Stops at the idle
position prevent inadvertent movement of the
thrust levers to cutoff. The idle stops can be
released by lifting a trigger on the outboard
side of each thrust lever (Figure 7-12).
When a thrust lever is placed in the CUT-OFF
position, the shutoff valve in the fuel control
unit is mechanically closed, and a switch also
actuates to provide a discrete signal to the
DEEC to initiate engine shutdown. In the com-
puter-on or computer off mode of operation,
the DEEC will initiate a white “L/R ENG
SHUTDOWN” message through the CAS
when the thrust lever is placed in the cutoff po-
sition. This will preempt messages for low fuel
pressure, low oil pressure, low hydraulic pres-
sure and generator failure.
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
7-17
FOR TRAINING PURPOSES ONLY
FlightSafety
international
Figure 7-12. Thrust Levers