King Air C90GTi, Руководство по подготовке пилотов

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tor will actuate the actuator downlock switch
to inter r upt cur rent to the pump motor. The
motor will continue to r un until all three
landing gears are down and locked. A spring-
loaded downlock assembly is f itted to each
main gear upper drag leg, providing posi-
tive downlock action for the main gear.
In flight, with the LDG GEAR CONTROL
in the DN position (Figure 14-8), as the land-
ing gear moves to the fully down position,
the downlock switches are actuated, and they
cause the landing gear relay to inter rupt cur-
rent to the pump motor. When the red GEAR-
I N - T R A N S I T l i g h t s i n t h e L D G G E A R
CONTROL switch handle extinguish, and
the g reen NOSE-L-R indicators illuminate,
the landing gear is in the fully down-and-
locked position.
A solenoid mounted on the valve body end
o f t h e p u m p i s e n e rg i z e d wh e n t h e L D G
GEAR CONTROL is in the UP position and
actuates the gear select valve, allowing sys-
tem fluid to flow to the retract side of the
s y s t e m . T h e g e a r s e l e c t va l v e i s s p r i n g -
loaded in the down position and will move
to the up position only when energized. The
nose gear actuator will unlock when 200 to
400 psi of hydraulic pressure is applied to
the retract por t of the nose gear actuator.
The landing gear will begin to retract after
the nose gear actuator is unlocked.
Hydraulic system pressure performs the up-
lock function, holding the landing gear in
the retracted position. When the hydraulic
pressure reaches approximately 1,850 psi,
the uplock pressure switch will cause the
landing gear relay to open and inter r upt the
cur rent to the pump motor. The same pres-
sure switch will cause the pump to actuate
should the hydraulic pressure drop to ap-
proximately 1,600 psi.
The landing gear control circuit is protected
by a 2-ampere circuit breaker located on the
pilot’s inboard subpanel. Power for the pump
motor is supplied through the landing gear
motor relay and a 60-ampere circuit breaker,
both of which are located under the cabin floor
in the wing center section. The motor relay is
energized by current from the 2-ampere cir-
cuit breaker and the downlock switches.
HYDRAULIC FLUID LEVEL
INDICATION SYSTEM
A c a u t i o n a n n u n c i a t o r p l a c a r d e d “ H Y D
FLUID LOW” (Figure 14-9), in the annun-
ciator panel, will illuminate (yellow) when-
ever the hydraulic fluid level in the landing
gear power pack reser voir is low. The an-
n u n c i a t o r i s t e s t e d by p r e s s i n g t h e H Y D
FLUID SENSOR TEST button located on the
pilot’s subpanel.
If the HYD FLD LOW annunciator comes
on, nor mal extension may be attempted, but
the pilot should be prepared for an emer-
gency manual extension.
Control
T h e l a n d i n g g e a r hy d r a u l i c p owe r p a c k
m o t o r i s c o n t r o l l e d by t h e l a n d i n g g e a r
s w i t c h h a n d l e p l a c a r d e d “ L D G G E A R
CONTROL” with UP and DN positions, lo-
cated on the pilot’s right subpanel (Figure
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
14-8
FOR TRAINING PURPOSES ONLY
14
LANDING
GEAR
AND
BRAKES
Figure 14-8. Landing Gear Control
Switch Handle