King Air C90GTi, Руководство по подготовке пилотов

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The r udder boost system consists of pneu-
matic actuators in the empennage which pro-
v i d e t h e r e q u i r e d r u d d e r d e f l e c t i o n u p o n
loss of an engine. A differential pressure
switch, mounted on the pneumatic manifold,
senses engine P
3
pressures. Upon sensing a
loss of P
3
on one engine, this pressure switch
will energize a solenoid to direct pneumatic
manifold air to the appropriate actuator.
D u r i n g o p e r a t i o n , a d i ff e r e n t i a l p r e s s u r e
switch senses bleed air pressure differences
between the engines. If the bleed air pres-
sure differential exceeds about 50 psi dif-
f e r e n t i a l p r e s s u r e , a s i g n a l f r o m t h e
differential pressure switch to one of the
lines to the r udder boost ser vos causes the
solenoid valve to open, and one of the ser-
vos is actuated. The pressurized ser vo will
then pull on one of the rudder cables. Tension
springs in the connection between the ser-
vos and the r udder cables take up the slack
in the r udder cable when one or the other of
the ser vos is actuated.
A drop in bleed air pressure from the left
engine will actuate the appropriate ser vo
and the right r udder pedal will move for-
ward. A drop in bleed air pressure from the
right engine will cause the left r udder pedal
to move forward. Pedal rigging causes the
opposite pedal to move in the opposite di-
rection. This system is intended to help com-
p e n s a t e f o r a s y m m e t r i c a l t h r u s t o n l y.
Appropriate trimming is to be done with the
trim controls.
The system is controlled by a toggle switch
( F i g u r e 1 5 - 7 ) , p l a c a r d e d R U D D E R
BOOST–OFF, located on the pedestal below
the aileron trim control knob. The switch
is to be in RUDDER BOOST position be-
fore flight.
T h e c i r c u i t i s p r o t e c t e d by t h e 5 - a m p e r e
RU D D E R B O O S T c i r c u i t b r e a ke r o n t h e
right side panel.
A preflight check of the system can be per-
for med during the r un-up by retarding the
power on one engine to idle, and advancing
power on the opposite engine until the power
d i ff e r e n c e b e t we e n t h e e n g i n e s i s g r e a t
enough to close the switch that activates the
r udder boost system. Movement of the ap-
propriate r udder pedal (left engine idling,
right r udder pedal moves forward) will be
noted when the switch closes, indicating the
system is functioning properly for low en-
gine power on that side. Repeat the check
with opposite power settings to check for
movement of the opposite r udder pedal.
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
15-6
FOR TRAINING PURPOSES ONLY
15
FLIGHT
CONTROLS
Figure 15-7. Rudder Boost Switch