PS Magazine - TB 43-PS-580
PS, The Preventative Maintenance Monthly
ISSUE 580
MARCH 2001
PS 580
MAR 01
39
CH-47D…
So, if you’re raising the ramp, keep your
hands on the ramp control handle and eye-
ball the ramp as it closes. If the sequence
valve sticks and the cargo door shoots out
too late, you can prevent the damage by
stopping the ramp before it closes.
Do not overtighten screws
Tighten
until lock-
washers
stop
slipping
Adjust
if ramp
sequence
valve
sticks
Keep
hands on
control
to stop
ramp
If you have trouble with the cargo
door, adjust the sequence valve per Task
7-282 of TM 1-1520-240-23. If it con-
tinues to stick, have your AVIM shop
test or repair it per Tasks 7-280 and
7-278 in the TM.
C
hinook crews, if you’ve got a sticking cargo door ramp sequence valve, you could
end up with a ramp that won’t close or seal properly. That could sink you like the
Titanic if you have to land your bird in the drink.
The sequence valve determines when
the cargo door extends from the ramp as
the ramp is closed.
When you set the control to close the
ramp, the valve may stick. If it does, the
cargo door extends too late. It tears the
ramp fiberglass coaming and rips the
weather seal around the ramp frame.
That seal is what keeps excess water out
in a water landing.
UH-60…
lack Hawk mechanics, don’t over-
tighten screws when you install access
panels after your 10-hour/14-day
inspections.
It’s easy to bear down too hard on the
screws when you reinstall the right and
left tail cone panels and the stabilator
panel.
But if you do, you’ll probably end up
rounding out the screw heads when you
remove them for the next inspection.
But avoid all that trouble by tighten-
ing the screws only until the lock wash-
ers stop slipping.
If you round out a
screw head, get your lead mechanic to
help you remove it. Always refer to your
general aircraft TM 1-1500-204-23 for
checking how tight a screw should be.
580. 38-39 (C)
1/31/01
11:11 PM
Page 1
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