Aircraft Hydraulic Power Requirements.
**CH-47 (Chinook) (Utility)
Models D, MH47-E (Flt Cont)
AH-1 (Huey Cobra)
* When using the return bypass in the OFF position, the aircraft reservoir may fill to the full position. This
is satisfactory for hydraulic operation.
** On CH-47D model aircraft the RESERVOIR selector valve (item 6, figure 2-15), must be in the AGPU position
until the OUTPUT switch (item 14, figure 2-15), is set on the ON position. The aircraft will then be supplied
with hydraulic power. The Reservoir Selector valve is then placed in the AIRCRAFT position and the Return
Bypass to BYPASS position. When hydraulic operations are completed, the Reservoir Selector valve is set to
AGPU position and the bypass valve is cycled to the OFF position to fill aircraft reservoir, to the BYPASS
position to drain aircraft reservoir, to bring the aircraft reservoir to operating range.
Hold the PRESSURE switch to IN-
Set OUTPUT switch to ON. Observe that
CREASE position until the specified aircraft operation
output light illuminates.
When using aircraft reservoir (CH-47D)
Shut Down Hydraulic System.
place the RETURN BYPASS to the BYPASS position
and then place the RESERVOIR selector valve to the
On the AH-64 move the RETURN BY-
PASS is in the OFF position.
Failure to reduce system pressure prior to shut-
ting down the hydraulic power can cause dam-
On the UH-60 move the RETURN BY-
age to the pressure compensator motor on the
PASS is in the BYPASS position or its reservoirs will
hydraulic pump and limit switched.