Learjet 60 - Page 305

Pilot's Manual

Learjet 60
GENERAL FLIGHT CHARACTERISTICS
(CONT)
Although
the flight control systems are
manual, stick forces are light
to moderate
throughout the flight envelope .
Stability is good at all air-
speeds and
airplane configurations . Aircraft
responsiveness and flight
control authority
are very good throughout
the flight envelope . A
yaw damper is
employed to damp lateral
oscillations caused by
tur-
bulent air ;
however, it is not required
for dispatch . Trim
changes due
to use
of the landing gear, flaps
and power are slight ;
however, a trim
change is required when
spoilers are extended or retracted .
The dual stall warning
system provides an excellent
indication of im-
pending airplane
stall . Additionally, the airplane
exhibits an aerody-
namic stall
warning buffet in all configurations .
The shaker actuates
at
least 7% above the stall speed
published in the Airplane Flight
Manual
. The shaker system produces a
high-frequency, low-
amplitude
vibration transmitted to the
control columns . As the shak-
ers actuate, the red low-speed awareness
cue reaches the center of the
airspeed display on the EFIS, the
angle-of-attack indicator needle
en-
ters the yellow arc and the stall warning
lights illuminate and flash .
Recovery is easily accomplished by
lowering the nose of the airplane
while simultaneously advancing
power as necessary to accelerate out
of the stall regime . Good
aircraft response, to elevator inputs, occurs
throughout the aircraft
operating envelope .
The spoiler
system provides an effective means of increasing
normal
rates of
descent and may be used as a drag device to achieve rapid
airspeed
deceleration . The spoilers are used just after touchdown to
spoil the lift for more effective braking action and to increase drag
for
minimum landing roll . Aileron augmentation is accomplished by the
spoiler system when the SPOILER switch is in the RET or ARM posi-
tion and the flaps are lowered beyond 25° .
8- 2
PM-123
Change l