PS Magazine - AUGUST 1985
PS, The Preventative Maintenance Monthly
ISSUE 393
AUGUST 1985
True, aircraft shims
aren't very sexy-
not even when they'Re
welL stacked. Admi±±edly²
i±'s
·
hard ±o get exci±ed abou±
³hem
:
which may be why ±hey
don'±
g
e± the at±ention ±hey deserve.
But if´ You lose a shiMµor
C
an'±
remember which
¶
one goeS where after
you've removed an engIne,
¸
¹r
º
ansmis»
¼
sion, pylon isoLa±ion mouN½ or
01±
cooler
mount¾i± couLd get embarrassing.
Worse ye±² i± could cos± ±he Army big
bucks. Tha±'s because your bird will
need a compLe±e Fselage alignment¿ ±o
de±eÀmine the proper ±hickness of each
shim repLacement. Tha± transLates into
special Ác±ory tooLing by depot mainteÂ
nance. ñ's ±he sor± of mÄstake ±hat could
pu± you in±o the doghouse wi±h your
main±enance supervisor¾permanen±ly.
Åosing or conFsing shims is easy if
you're no± extra careFl when removing
power plan± moun±s and suppor±s Ær
main±enance. Çhims are precisely
AUG 85
.±
Èachined and bonded ±o ±he Éselage ±o pr
he exact amoun± of cushion
under each mount fitting so ±hat all components are perÊctly aligneD.
Shims are precisely
Machined
The bes± way ±o avoid improper shimming is to measure ±he ±hickness of all
shims and record their Loca±ions on ËA Ìorm
24²³-´µ.
To keep Íom Losing shims ±ha± vibra±e loose, bond ±hem back in place as soon
²easure thickness aNd
rec
³
ORd
Location
o·
´f aLL µhIms
8
•
±
E
8
- )
¶
BoNd loose shims
bacK in place
as you discover ±hey're Loose. Apply adhesive, ÎÇÏ
³²4²-²²¶²´6-³662,
around
±he outer edges of ±he shims to secure ±hem. Ãf they can'± be rebonded to ±he
Ðselage right away, ±ag or marK them Ñr positive identiÒication and pu± ±hem
in a saÓ place.
AUG ·¸
57
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