(b)
Keep the center hydraulic system without pressure for not less than 2 minutes to permit the pressure to bleed from the RAT.
(c)
Do these steps: 1) Pressurize the center hydraulic system (AMM 29-11-00/201). 2) Make sure that the RAT turbine blades and hub do not turn. 3) If the turbine blades and hub turn, remove the pressure
from the center hydraulic system and permit the pressure to fully bleed from the RAT.
(d)
Do the above steps until the RAT turbine blades and hub do not turn when the center hydraulic system is pressurized.
S 865-104
(21)
Remove power from the center hydraulic system (AMM 29-11-00/201).
S 215-105
(22)
Make sure the RAT green pressure light on the engine start/RAT control panel goes off when the center system pressure is removed.
NOTE: The RAT pressure light can go off because of internal
____ pressure bleedoff before the center system pressure is removed.
S 865-106
(23)
Move the back-drive handle to the back-drive position and then release the handle.
S 215-107
(24)
Make sure the spring puts the handle back in the usual position.
S 435-108
(25)
Safety the back-drive handle with wire.
S 215-109
(26)
Make sure there is no leakage at the RAT swivel valves or hydraulic connections.
S 225-110
(27)
Make sure the RAT shaft seal leakage is no more than one drop in 30 minutes with the RAT not in operation.
S 095-111
CAUTION: REMOVE THE RAT SAFETY SCREEN BEFORE YOU RETRACT THE RAT.
_______ IF THE RAT IS RETRACTED WITH THE SAFETY SCREEN IN POSITION, EQUIPMENT DAMAGE CAN OCCUR.
(28) If you used the alternate method of roping off the area, remove the rope. If you used the RAT safety screed method, do these steps to remove the RAT safety screen (Fig. 502):
(a) Move the lifting fixture below the safety screen.
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MAINTENANCE MANUAL
(b)
Lift the safety screen support with the lifting fixture until the support touches the screen.
(c)
Put the strap around the safety screen and tighten the strap.
(d)
Remove the bolts and move apart the forward and aft cages of the safety screen.
CAUTION:_______REMOVE THE SAFETY SCREEN FORWARD CAGE CAREFULLY. IF THE CAGE TOUCHES THE TURBINE BLADES IT CAN CAUSE DAMAGE TO THE BLADES OR THE GOVERNOR MECHANISM.
(e)
Move the forward cage away from the RAT and lower the cage with the lifting fixture.
(f)
Loosen the knurled retainer nut on the adjustment screw on each side of the brace in the aft cage.
(g)
Turn both adjustment screws to retract the pads on the end of the adjustment screws.
NOTE: This will give clearance to remove the aft cage from the
____
RAT hydraulic pump.
(h)
Hold the aft cage and remove the top bolt, spacer, and nut from the brace inside the cage.
(i)
Remove the aft cage from the RAT.
(j) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：757 AMM 飞机维护手册 液压 CHAPTER 29 - HYDRAULIC POWER 2(61)
