FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 11. Aircraft Electrical Systems | 19. Protection of Unused Connectors | 11-261. Quick Reference Chart
9/27/01
AC 43.13-1B CHG 1
SECTION 19. UNUSED CONNECTORS AND UNUSED WIRES
11-260. GENERAL. Connectors may have
one or more contact cavities that are not used.
Depending on the connector installation, un-
used connector contact cavities may need to be
properly sealed to avoid damage to the con-
nector, or have string wire installed. Unused
wires can be secured by tying into a bundle or
secured to a permanent structure; individually
cut with strands even with insulation; or pre-
insulated closed end connector or 1 inch piece
of insulating tubing folded and tied back.
11-261. QUICK REFERENCE CHART.
A quick reference chart of unused connector
contact cavity requirements is given in ta-
ble 11-25. These requirements apply to har-
ness manufacturing or connector replacement
only.
11-262. UNPRESSURIZED AREA CON-
NECTORS. Connectors may be installed in
unpressurized areas of the aircraft. Unused
connector contact cavities installed in unpres-
surized areas should be properly sealed as fol-
lows:
a. Firewall Connectors Installations.
Firewall unused connector contact cavities
should be filled with spare contacts and stub
wires. (See figure 11-39.)
(1) Construct stub wires using high
temperature wire (260 ºC). Ensure that stub
wires are of the same type of wires in the bun-
dle.
(2) Crimp the proper contact, for the
connector and cavity being used, onto the wire.
Install the crimped contact into the unused
cavity.
(3) Extend stub wires beyond the back
of the connector clamp from 1.5 to 6 inches.
Feather trim stub wires to taper wire bundle.
(4) Secure wire ends with high tem
perature (greater than 250 ºC) lacing cord.
Nylon cable ties are not allowed for this in-
stallation.
NOTE: Both connectors mating
through the engine fire-seal are con-
sidered firewall connectors. Connec-
tors mounted on or near, but not
through, the engine fire-seal are not
considered firewall connectors.
b. Non-firewall Connector Installations.
In this type of installation all unused connector
cavities must also be filled with spare contacts.
It is not required, however, to crimp stub wires
on filling contacts.
Fill unused contact cavities with spare contacts
and Teflon sealing plugs or rods. (See fig-
ure 11-40.) Rods shall be cut so that they ex-
tend 1/8 to 1/4 inch beyond the surface of the
grommet when bottomed against the end of the
spare contact. (See table 11-26 for dimen-
sions.)
11-263. PRESSURIZED AREAS. Con-
nectors installed in pressurized areas of the
aircraft may be divided into two main installa-
tion categories, sealed and unsealed.
a. Sealed connector installations. Sealed
connectors installed in pressurized areas must
have their unused contact cavities filled with
Teflon sealing plugs or rods. (See fig-
ure 11-40.) Installation of spare contacts is
optional, except for future wiring addition re-
quirements. (See paragraph 11-234). No stub
wires are required.
b. Unsealed Connector Installations. It
is not required to fill unused contact cavities of
unsealed connectors installed in pressurized
areas with Teflon sealing plugs or rods. In-
stallation of spare contacts is optional, except
for future wiring addition requirements. (See
paragraph 11-234.)
Par 11-260
Page 11-103