TM 55-1520-240-23-4
5-70
REPAIR BLADE FAIRING — DOUBLE SKIN
(Continued)
5-70
j.
Start vacuum pump. Check for leaks.
Reposition polyvinyl sheet (E284) (38) or add
tape (E396) (34) 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 140º - 160ºF (60º - 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 (21º -
27ºC) in 24 hours. Vacuum may be
removed after 12 hours.
m.
Turn off vacuum pump.
n.
Remove sheet (38), tubes (35), tape (34),
fiberglass (33), rubber (32), fabric (31), and
peel ply (30).
o.
If squeezeout fairing is not satisfactory, fair
patch (15). Use adhesive (E40, E41, E43, or
E47.1). Follow step 18, 19, 20, or 21 to mix
adhesive.
NOTE
All blade repairs, weight adjustment,
painting, or balancing will be recorded
on rotor blade DA Form 2408-16,
each blade requires a separate form.
If the rotor blade does not have a DA
Form 2408-16, one must be prepared
and all actions recorded, as example;
location of repair, size of repair,
weight of repair, and required weight
adjustments for track and balance.
5-398
