DO NOT use oil or oil based materials
as NDI couplants on advanced composite
components. Use only water or water based
materials. Disbonds may result and loss of
structural integrity may occur.
(b) Deine both the depth and extent of the
damage using NDI according to para-
nical manual. Lay out the damage as
terlines to be used as reference marks
for positioning patch.
Damage Bolted Repair, External Patch
(c) Remove NDI couplant by wiping with
(1) Facilities, Equipment and Materials. The
clean, water moistened cloth.
following equipment and materials are required: Drill
motor, Drill guide, Drill bits, high-speed steel, Drill
reamer, carbide, straight lute or Drill bits, 8 Faceted,
Center punch, Temporary fasteners, Approved marker,
Grip Length Gauge, Vacuum Cleaner, HEPA Filter,
DO NOT damage inner surface of opposite
Composite Fasteners Installation Tooling, Patch mate-
skin or internal structure during machining or
rial (See System Speciic Technical Manual), Silicon
Carbide Abrasive Paper, Wiping Cloth, Composite
Blind Fastener (see System Speciic Technical Man-
(d) Remove skin damage along the dam-
age layout line as described in para-
The following procedure assumes the sys-
(e) Fabricate metallic patch as described
tem speciic technical manual or engineering
in TM 1-1500-204-23-10 or the system
has provided a fastener layout based upon
speciic technical manual. Refer to the
the repair design and/or criteria. Use an
system speciic technical manual for
approved drill guide for all drilling operations.
Consult the system speciic technical manual
fastener hole pattern layout.
Lay out patch on required material.
(2) Procedure for A Bolted Repair.
Cut out patch and chamfer edges.
(a) Remove dirt, grease and aircraft luids
from repair area as described in para-
Form contour in patch if required.
required to contain composite residue.
Moistened wiping cloth may be used as