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 | 2-45. Doped-on Patch Repair
9/8/98
AC 43.13-1B
c. The finishing tape width should be
6 inches wide if the opening is over 16 inches
long in any direction, is located on a wing top
surface, or the aircraft Vne speed is greater
than 150 mph.
Step 1. Tie the thread ends together with a
square knot.
2-45. DOPED-ON PATCH REPAIR. An
opening not over 8 inches in length in any di
rection, on an aircraft with a Vne speed less
than 150 mph, may be repaired with a 2-inch
overlapped and doped patch. The opening
should be trimmed to eliminate any irregular
edges and old pigmented dope coats removed
as described in paragraph 2-42.
Step 2. Start the stitch by routing through the
loop, positioning the square knot on the inside.
a. When installing a fabric patch over a
small opening, the loose edge of the fabric
around the opening may be secured by ex
tending a series of small threads, from the edge
across the opening, to the opposite side. After
the patch is completed, the threads may be
clipped and removed through an access port or
left in place.
Step 3. Complete the hand-stitch and secure the
stitching with a half hitch at a maximum each
10 stitches.
FIGURE 2-14. Hand-stitch detail.
dope and smoothed out with no voids or wrin
kles. Additional coats of clear dope and pig
mented dope are then applied to obtain the de
sired tautness and finish, as described in para
graph 2-21.
b. The fabric patch is installed by ap
plying a coat of clear dope around the opening,
then positioning the patch over the opening.
Brush out any void or wrinkles while saturat
ing only the fabric overlap area. After the first
coat of clear dope around the edge has dried
1 hour at 70 °F, wet the fabric patch to remove
any creases as described in paragraph 2-21.
After drying, apply additional coats of clear
dope and pigmented dope over the entire patch
as described in paragraph 2-21.
c. If the opening is less than 8 inches in
length in any direction and the aircraft Vne
speed is greater than 150 mph, a 2-inch wide
finishing tape should be installed on all sides,
centered on the edge of the 2-inch overlap
patch.
b. If the opening is more than 8 inches
but less than 16 inches long in any direction,
the finishing tape should be 4 inches wide.
d. If the opening is more than 8 inches
but less than 16 inches in length, in any direc
tion on an aircraft with a Vne speed less than
Par 2-44
Page 2-39