S 865-181
(19)
Make sure the RAT blades and hub stop.
NOTE: It is possible that the RAT blades and hub will continue to
____ turn slowly after you release the control handle. The cause of this condition is a check valve, in the RAT strut, which did not open while the speed of the RAT blades decreased. The check valve will open when you remove the hydraulic pressure. When you supply hydraulic pressure again, the RAT blades will not move. It is not necessary to reject parts because of this condition.
S 215-182
(20)
If the RAT blades and hub continue to slowly turn when the handle is not in the back-drive position, do these steps:
(a)
Remove the center hydraulic system pressure (AMM 29-11-00/201).
(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.
(21)
Remove power from the center hydraulic system (AMM 29-11-00/201).
S 865-183
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MAINTENANCE MANUAL
S 215-184
(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 865-185
(23)
Move the back-drive handle to the back-drive position and then release the handle.
S 215-186
(24)
Make sure the spring puts the handle back in the usual position.
S 435-187
(25)
Safety the back-drive handle with wire.
S 215-188
(26)
Make sure there is no leakage at the RAT swivel valves or hydraulic connections.
S 225-189
(27)
Make sure the RAT shaft seal leakage is no more than one drop in 30 minutes with the RAT not in operation.
S 095-190
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) Do these steps to remove the RAT safety screen (Fig. 502):
(a)
Move the lifting fixture below the safety screen.
(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.
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