Alternate Extension System Shuttle Valve
Figure 6A
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(2)
The door locked switch is a mechanical rotary-type switch. It is used to supply an input when the door safety valve is turned and locked in the OFF (safety) position. The switch operates when its roller touches the safety valve cam. When the safety valve is locked in the safety position, the door is hydraulically safe. The locked switch will then make the red door not safe light go off. The door switch for the main landing gear is installed behind the door safety valve in the wheel well for the main landing gear. The door switch for the nose landing gear is installed below the door release interlock actuator in the wheel well for the nose landing gear.
J.
Door Ground Control Switches (Fig. 10)
____________________________
SEE A
FWD
ALTERNATE HYDRAULIC EXTENSION
NOSE WHEEL WELL (CEILING)
PRESSURE PRESSURE SWITCH LINE
A
Hydraulic Pressure Switch Figure 7
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SEE B
SEE A
MAIN LANDING GEAR WHEEL WELLS
MAIN LANDING GEAR WHEEL WELLS (KEEL BEAM)(OUTBOARD WALL)
SEE C
DOOR SAFETY VALVE
DOORCLOSED SWITCH
A
B
DOOR LOCKED SWITCH
SEE D
DOOR
VALVE CAM SAFETY SWITCH LOCKED DOOR ON OFF DOOR SAFETY
VALVE
LATCH CAM
C D
Main Landing Gear Door Closed and Locked Switches
Figure 8
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SEE B
FWD
SEE A
DOOR
NOSE LANDING GEAR WHEEL WELL
CLOSED
(FORWARD WALL)
SWITCH
A
SEQUENCING
CRANK CAM
DOOR RELEASE
INTERLOCK
ACTUATOR
LATCH
ON OFF
DOOR
LOCKED DOOR
SWITCH LOCKED
SEE C SWITCH
B C
Nose Landing Gear Door Closed and Locked Switches Figure 9
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NOSE LANDING GEAR LEFT EQUIPMENT PANEL, P63
SEE A
DOOR CLOSE
S10193
OFF
SWITCH NOSE DOOR CLOSE ON
OFF
S00324
SWITCH NLG
W/W INSP LT
S10361
NOSE GEAR DOOR
UNSAFE LIGHT
PRESS TO TEST SW
A
N0SE LANDING GEAR DOOR CLOSE SWITCH
MAIN WHEEL WELL ELECTRICAL SERVICE PANEL, P72
SEE C SEE B
RIGHT MAIN ALL DOORS ALL DOORS OPENLANDING OPEN SWITCH ARM SWITCHGEAR DOOR
MAIN LANDING GEAR DOOR CLOSE SWITCH
B
C
Door Ground Control Switches Figure 10
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(1)
The door ground control switches are used to open and close the landing gear doors to get access to the wheel wells. There are two switches, the ALL DOORS OPEN ARM and the ALL DOORS OPEN switches. They are operated at the same time to open all three landing gear doors together. These switches are momentary toggle switches which supply electrical power to the power pack the same as the ALTN EXTENSION switch. There is a switch to close the doors for the nose landing gear and a switch to close the doors for the two main landing gear. They operate independently. With hydraulic power supplied and the control lever for the landing gear in DN, the MAIN or NOSE GEAR DOOR CLOSE switch is operated to close the related doors. These switches are also momentary toggle switches. They supply electrical power to the door-release-interlock-actuator solenoid.
(2)
The two (door open) switches and the main landing gear (door close) switch are found on the electrical service panel for the MLG wheel wells, P72. This panel is found on the bottom of the fuselage immediately aft of the doors for the main landing gear. The nose landing gear (door close) switch is found on the left equipment panel for the nose landing gear, P63. This panel can be found on the shock strut for the nose landing gear.
3. Operation (Fig. 11)
_________
A. Functional Description
(1)
Landing Gear Alternate Extension
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本文链接地址：757 AMM 飞机维护手册 起落架 CHAPTER 32 - LANDING GEAR 2(92)
