FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 11. Aircraft Electrical Systems | 8. Wiring Installation Inspection Requirements | 11-101. Junction Boxes, Panels, Shields, and Microswitch Housings
AC 43.13-1B CHG 1
9/27/01
wiring must be clearly identified and must be
routed and clamped so that it cannot be mis-
matched.
FLEXIBLE METALLIC AND RIGID
NONMETALLIC. Inspection of conduit as-
semblies should ascertain that:
j. Connectors in unpressurized areas
should be positioned so that moisture will
drain out of them when unmated. Wires exit-
ing connectors must be routed so that moisture
drains away from them.
a. Conduit is relieved of strain and flex-
ing of ferrules.
b. Conduit is not collapsed or flattened
from excessive bending.
11-101. JUNCTION BOXES, PANELS,
SHIELDS, AND MICROSWITCH HOUS-
INGS. Examine housing assemblies to ascer-
tain the following:
a. Verify that one or more suitable
holes, about 3/8-inch diameter, but not less
than 1/8-inch diameter, are provided at the
lowest point of the box, except vapor-tight
boxes, to allow for drainage with the aircraft
on the ground or in level flight.
b. Verify that vapor tight or explosion
proof boxes are externally labeled VAPOR-
TIGHT or EXPLOSION PROOF.
c. Verify that boxes are securely
mounted.
d. Verify that boxes are clean internally
and free of foreign objects.
e. Verify that safety wiring is installed
on all lid fasteners on J-boxes, panels, shields,
or microswitch housings which are installed in
areas not accessible for inspection in flight,
unless the fasteners incorporate self-locking
devices.
f. Verify that box wiring is properly
aligned.
g. Verify that there are no unplugged, un-
used holes (except drainage holes) in boxes.
c. Conduits will not trap fluids or con-
densed moisture. Suitable drain holes should
be provided at the low points.
d. Bonding clamps do not cause damage
to the conduit.
e. Weatherproof shields on flexible con-
duits of the nose and main landing gear and in
wheel wells are not broken; that metallic braid
of weatherproof conduit is not exposed; and
that conduit nuts, ferrules, and conduit fittings
are installed securely.
f. Ends of open conduits are flared or
routed to avoid sharp edges that could chafe
wires exiting from the conduit.
11-103. JUNCTIONS. Ensure that only air-
craft manufacturer approved devices, such as
solderless type terminals, terminal blocks,
connectors, disconnect splices, permanent
splices, and feed-through bushings are used for
cable junctions. Inspect for the provisions
outlined below:
a. Electrical junctions should be pro-
tected from short circuits resulting from
movement of personnel, cargo, cases, and
other loose or stored materials. Protection
should be provided by covering the junction,
installing them in junction boxes, or by locat-
ing them in such a manner that additional pro-
tection is not required, etc.
11-102. CONDUIT - RIGID METALLIC,
Page 11-48
Par 11-100