FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 2. Fabric Covering | 4. Repairs to Fabric Covering | 2-42. General
9/8/98
SECTION 4. REPAIRS TO FABRIC COVERING
AC 43.13-1B
2-42. GENERAL. All materials used to
make repairs to fabric covering must be of a
quality at least equal to the original materials.
Workmanship and repair methods must be
made in a manner that will return the fabric
covering to its original airworthy condition.
a. Any combination of seams hand-sewn
and overlapped and doped may be used to
make repairs and install new fabric sections.
(See paragraph 2-7.)
b. All pigmented dope coats, including
aluminum-pigmented coats, should be re
moved to the clear dope preliminary coats be
fore installing a new fabric section or finishing
tape on the old fabric. The appropriate dope
thinner (see paragraph 2-20) may be applied
with a brush to soften the old dope. The sof
tened coats can then be removed down to the
clear dope coats by scraping with a dull-bladed
knife while supporting the fabric from the back
side. Removing the old dope by sanding is
optional.
rib lacing or other methods, the new fabric
section should be extended 3 inches past the
structural member.
NOTE: Before installing new finish-
ing tape, duplicate the original rib
lacing or other attachments without
removing the original rib lacing or at-
tachment. Removing the original fin-
ishing tape is optional.
g. When installing large sections of fab-
ric on a wing or other components, all ma
chine-sewn and/or overlapped and doped
seams should be made in accordance with the
guidelines specified in paragraphs 2-7 and 2-8.
h. When repairing a covering material
other than cotton or linen, which was ap
proved with the manufacturer’s type certificate
(TC), or approved under the authority of an
STC, follow the repair instructions furnished
by the aircraft manufacturer or supplier of the
STC-approved covering materials.
c. Avoid allowing dope to run down the
back side of the fabric or drip through the wing
onto the back side of the opposite surface,
which will cause cosmetic damage and will
show in a high gloss finish.
d. Repairing a new fabric section over
two adjacent wing ribs is considered a major
repair. A log book entry and an FAA
Form 337 must be processed accordingly.
e. All fabric patch edges not covered
with a finishing tape should have a pinked
edge or a 1/4-inch raveled edge.
f. Where the edge of a new fabric sec-
tion will be located within 1 inch of a struc
tural member to which the fabric is attached by
2-43. REPAIR OF TEARS AND ACCESS
OPENINGS. When all the original fabric is
intact, an opening may be repaired by sewing
the two sides together with a curved needle as
illustrated in figures 2-13 and 2-14. The fabric
edges should be pulled together uniformly with
no wrinkles. Before sewing, remove the old
dope coats down to the clear dope coats a dis
tance of 2 inches on each side of the opening.
The hand-sewn thread quality should be at
least equal to that specified in table 2-2 and
treated with wax (paraffin-free or beeswax) to
prevent fraying, or use the proper thread on the
STC application. After sewing, apply a coat
of clear dope over the cleaned area and install
a 3-inch wide finishing tape, centered over the
stitches.
Par 2-42
Page 2-37