TM 55-1520-240-23-4
5-81.3.1
REPLACE LIGHTNING PROTECTION JUMPER STRIP
(Continued)
5-81.3.1
17.
Bond repair as follows:
a.
Cover repair with layer of peel ply (E270) (9)
and layer of Teflon-impregnated fabric (E170)
(10). Make layers large enough to overlap
patch (22) 1 inch.
b.
Cover Teflon-impregnated fabric (E170) (10).
Use thick rubber pad (E318) (11).
c.
Cover repair area with fiberglass cloth (E132)
(12). Cut cloth large enough to cover rubber
pad (E318) (11).
d.
Surround cloth (E132) (12) with sealing tape
(E396) (13). Keep tape clear of cloth.
e.
Attach tube (14) to vacuum pump hose.
f.
Wrap tube (14) with two layers of fiberglass
cloth (E132) (15). Apply masking tape (E388)
over cloth.
g.
Position tube (14) on cloth (E132) (12)
covering repair. Wrap tube with sealing tape
(E396) (16) where tube crosses sealing tape
(13) already applied.
h.
Press tube (14) onto tape (13) to make
airtight seal.
i.
Press polyvinyl sheet (E284) (17) smoothly
onto tape (13) to make airtight seal.
j.
Start vacuum pump. Check for leaks.
Reposition polyvinyl sheet (E284) (17) or add
tape (E396) (13) as needed.
k.
Maintain 20 inches Hg vacuum through
adhesive cure.
Do not exceed 160ºF (71ºC) at blade
surface. Damage to fiberglass can
occur.
l.
Cure adhesive at 150º - 160ºF (66º - 71ºC)
for 2 hours. Use heat lamp. Monitor
temperature. Use temperature indicating
strips (E413).
NOTE
Serviceable cure can be achieved
without heat at 70º - 80ºF (21 -
27ºC) in 24 hours. Vacuum may be
removed after 12 hours.
m.
Turn off vacuum pump.
n.
Remove peel ply (9) fabric (10), rubber (11),
fiberglass (12), tape (13), tube (14), and
sheet (17).
18.
Fair adhesive squeezeout to surrounding blade
surface. Use abrasive paper (E9). If fairing was
not achieved by squeezeout, mix additional
adhesive (E40, E41, E43 or E47.1) as directed
in step 8, 9, 10, or 11.
FOLLOW-ON MAINTENANCE:
Refinish repair area (Task 5-82).
END OF TASK
5-483
