曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
mechanism. Hydraulic power for thrust reverser operation is supplied
by the aircraft hydraulic system. A selector valve for each thrust reverser
is installed in the tailcone. The selector valves control hydraulic flow
to the associated system actuators in response to electrical inputs from
the associated thrust reverser lever and position switches via the thrust
reverser control unit.
The thrust reverser levers and the system circuit breakers are the only
controls used by the crew to operate the system. Electrical power for
thrust reverser control and indication circuits is 28-vdc supplied by the
L and R ESS buses through the L and R REVERSER circuit breakers. The
L REVERSER circuit breakers located in the ENGINE group of the pilot’s
circuit breaker panel include the 5-amp DEPLOY, the 3-amp ANN,
and the 3-amp STOW. The R REVERSER circuit breakers located within
the ENGINE group of the copilot’s circuit breaker panel also include a
5-amp DEPLOY, a 3-amp ANN, and a 3-amp STOW.
In order to arm the thrust reversers, both main gear weight-on-wheels
switches must be in the ground mode (aircraft weight on the main gear)
and the thrust levers must be in the IDLE position. When fully armed
(reverser system relays and switches are properly sequenced), the associated
isolation valve is open and the system is ready for deploy/stow
commands by operation of the thrust reverser levers.
The clam-shell type blocker doors are held in the stowed position by
latch hooks. The latch hooks are hinged to the unlatch actuator, and are
rotated away from the blocker doors for thrust reverser deployment.
When the deploy cycle is initiated, hydraulic pressure is applied to the
stow side of the primary actuators which move the doors into an
Pilot’s Manual
2-26 PM-126A
overstowed condition. Overstowing the thrust reversers allows the unlatch
actuators to rotate the latch hooks. As the latch hooks begin to rotate,
the unlock switch signals the thrust reverser control unit of the
unlocked condition. As the latch hooks clear the blocker door receptacles,
an unlatch switch signals the thrust reverser control unit that the
blocker doors are unlatched. After the latch hooks are unlatched, hydraulic
pressure is applied to the deploy side of the primary actuators
which push the doors open.
Stow is initiated automatically whenever an unlock condition is detected
and the thrust reverser lever is forward of the thrust reverser deploy
detent. This occurs during the normal stow cycle and also to correct an
abnormal condition in flight. During autostow, hydraulic pressure is
applied to the stow side of the primary actuators and the blocker doors
move towards the overstow position. As the doors reach overstow, the
spring-loaded latches close. When the latches close, the unlock switches
are deactivated. The selector valve then releases stow pressure on the
primary stow/deploy actuator. Exhaust gas pressure and springs return
the doors to the normal stowed position.
An automatic throttle retard mechanism is installed on each thrust reverser
to ensure that thrust reverser stow and deploy does not occur
with an engine thrust setting above idle. The throttle retard mechanism
consists of an actuator, crank, and lever. Whenever hydraulic stow
pressure is applied to the thrust reverser actuators, the throttle retard
mechanism will position thrust lever to the IDLE position. When hydraulic
stow pressure is removed, the mechanism will return to a neutral
position and release retard pressure to the thrust lever.
THRUST REVERSER LEVERS
A thrust reverser control lever for each thrust reverser is mounted
piggy-back fashion on each main thrust lever. The thrust reverser levers
are inoperable and cannot be moved unless the associated main thrust
levers are at the IDLE stop. Similarly, the main thrust levers cannot be
moved from the IDLE position until the associated thrust reverser lever
is in the stow (full down) position. When fully armed, a thrust reverser
may be independently deployed by lifting the corresponding thrust reverser
lever to the first (idle/deploy) stop. A throttle release will activate
and the thrust reverser lever may be pulled beyond the idle/
deploy stop to increase reverse thrust. If both thrust reversers are deployed,
a detent limits thrust reverser lever travel to approximately
MCR.
The thrust reverser is stowed by first returning the thrust reverser lever
to the idle/deploy stop and then moving the lever to the stow (full
down) position at engine idle speed.
Pilot’s Manual
PM-126A 2-27
THRUST REVERSER INDICATIONS
Thrust reverser control is automatic and status indications are displayed
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Bombardier_Learjet-General_Description(19)
